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Diseases & Conditions

Susac Syndrome

Susac Syndrome is an autoimmune disease that affects the brain, eye (retina) and inner ear.

Brain Eye Inner Ear
Headache (often migraine-like) Visual disturbance; visual field deficit Hearing loss
Short term memory difficulty The patient notes an area within their field of vision in which they "can't see anything." Tinnitus (ringing, or buzzing in ear---often "roaring")
Slow thought processing Patients describe these areas as a "dark spot," "black spot," "pink spot," or a "hole" in their visual field. Vertigo (whirling dizziness)
Confusion The medical term for this phenomenon is scotoma. Loss of balance
Impaired decision-making and judgment Loss of peripheral vision
Other cognitive dysfunction

This section is intended to help patients, families, their friends, and health care professionals to better understand Susac Syndrome. It is designed to answer questions like:

  • How does Susac Syndrome present?
  • What symptoms and other abnormalities can it produce in the eyes, brain and inner ear?
  • What do we know about the cause?
  • How is it diagnosed or misdiagnosed?
  • How does Susac Syndrome behave over time?
  • How is Susac Syndrome treated and optimally followed?
Brief Description

Susac Syndrome is an autoimmune disease that affects the microvasculature (tiniest arteries and capillaries) of the brain, retina and inner ear---resulting in varying degrees of ischemic injury (injury due to decreased blood flow and oxygen) to these tissues. By autoimmune, we mean that a person's own immune system is mistakenly attacking part of that person's own body. For an explanation of the "immune system" and "autoimmune mistake," go to the section entitled "The Immune System, Autoimmune Mistakes, and the Concept of Immunological Self-Correction" at the end of this section.

Download a PDF to read a brief description Susac Syndrome.


Because Susac Syndrome is due to injury to the microvasculature in the brain, retina, and inner ear, it causes the following categories of symptoms:

  • Brain Symptoms – Cognitive dysfunction and other neurologic symptoms
  • Eye Symptoms – Visual disturbance
  • Inner Ear Symptoms – Hearing loss, Vertigo, Tinnitus

Download a PDF to read a detailed list of the "Symptoms" associated with Susac Syndrome.


The key to understanding Susac Syndrome is to appreciate the concept of "Autoimmune Endotheliopathy."

  • "Endotheliopathy" means that the endothelial cells (EC) are sick.
  • "Autoimmune" means that the endothelial cells are sick because the person's own immune system is mistakenly waging an attack on those cells, thereby injuring them.

Download a PDF to read more on the "Cause."


Ophthalmologic Findings of Susac Syndrome

Autoimmune Endotheliopathy In The Retinal Vasculature

Patients with Susac Syndrome typically notice "dark spots" in one or both of their visual fields. This "dark spot" obstructs their vision in that particular portion of their visual field, so that they "can't see anything" in that particular spot. The patient might say, "When I look at your face, I can't see part of it." Some patients describe this as a "black spot," a "pink spot," or a "shadow." Sometimes, instead, patients complain of "flashing lights" appearing somewhere in their visual field.

Download a PDF to read more on the "Ophthalmologic Findings of Susac Syndrome."


This MRI reveals 5 obvious "holes in the corpus callosum.

Autoimmune Endotheliopathy in The Brain

The same endothelial cell swelling, loss of tight-junctions, "leakage," and partial/complete occlusion that is going on in the tiny blood vessels of the retina (see "Eye" section) can go on in the microvasculature of the brain and explains the brain disturbances and the typical MRI brain abnormalities of Susac Syndrome.

MRI abnormalities in Susac Syndrome include the following:

  • Abnormalities in the Corpus Callosum:
    • "Snowballs"
    • Linear defects ("Spokes")
    • "Holes"

These corpus callosal abnormalities are located in the central portion of the corpus callosum, as opposed to the under-surface of the corpus callosum.

Download a PDF to read more on the "Autoimmune Endotheliopathy In The Brain."


Autoimmune Endotheliopathy In The Inner Ear: Audiologic Abnormalities of SS

The third component of the Susac Syndrome clinical triad is inner ear involvement---involvement of the cochlea and the vestibular apparatus. Again, it is an autoimmune endotheliopathy in the microvascular of the inner ear that is the problem. This endotheliopathy leads to narrowing of the channel within the tiny blood vessels that feed the cochlea and vestibular apparatus, and the resultant decreased blood flow and decreased delivery of oxygen and nutrients causes ischemic injury to these tissues.

The figure at right shows the anatomy of the inner ear. Because it is the blood supply to the tip of the cochlea that is most vulnerable, and because the tip of the cochlea is responsible for hearing sounds of low frequency, the autoimmune endotheliopathy of Susac Syndrome primarily causes low frequency sensorineural hearing loss. Loss at other frequencies, however, can also occur. The hearing loss of Susac Syndrome can be on one side, both sides, equal, or unequal. It can develop suddenly, or more progressively. It can be so profound as to require cochlear implants.

Download a PDF to read more on "Autoimmune Endotheliopathy in the Inner Ear."

Clinical Course

The clinical course (how the disease behaves over time) and long term outcome of Susac Syndrome differ from patient to patient. Many patients experience an acute or subacute "monophasic encephalopathic course" (figure to right) that lasts 1-2 years and is not followed by any further disease activity.

If the disease during those 1-2 years is relatively mild or is otherwise easily controlled by immunosuppressive medication, the outcome can be very good, i.e. little or no permanent damage sustained. With more severe disease, more prolonged disease, or both, there is potential for permanent, severe irreversible damage, i.e. varying degrees of dementia, visual loss, and deafness.

Download a PDF to read more about the clinical course of Susac Syndrome.


Ideally, treatment of Susac Syndrome should be based on:

  • An accurate understanding of the immunopathogenesis (cause) of the disease.
  • An accurate understanding of the natural history and potential outcome of the disease.
  • The results of controlled clinical trials.
  • Individualized consideration of the risks of under-treatment versus the risks of over-treatment.

Unfortunately, our understanding of the immunopathogenesis of Susac Syndrome is quite incomplete. And, to date, our knowledge of the natural history and treatment of Susac Syndrome is based entirely on anecdotal case reports and retrospective analyses of short series of patients. No comprehensive, systematic and prospective study of the clinical features, clinical course, and treatment of Susac Syndrome has been conducted. No controlled studies of treatment have been conducted.

Download a PDF to read more on "Treatment."

Differential Diagnosis

Many different diseases need to be considered before making a definite diagnosis of Susac Syndrome. Conversely, Susac Syndrome is often misdiagnosed, for example, as "atypical multiple sclerosis (MS)," "unusual demyelinating disease," "atypical ADEM (acute disseminated encephalomyelitis)," or "atypical complex migraine." Therefore, to avoid over-diagnosis and misdiagnosis of Susac Syndrome, it is wise to consider the disease categories listed below:

  • Demyelinating Diseases
  • Autoimmune/Rheumatologic diseases
  • Non-Inflammatory Cerebrovascular disease
  • Infectious CNS disease
  • Malignancy
  • Primary CNS lymphoma
  • Metastatic CNS malignancy
  • Paraneoplastic CNS syndromes
  • Migraine syndromes
  • Meniere's disease
  • Psychiatric disease
  • Other Encephalopathy

Download a PDF to read more on "Differential Diagnosis."

Cleveland Clinic has established a Susac Syndrome Program to provide clinical services for patients with Susac’s syndrome. The Susac’s Syndrome Program, which is directed by Robert Rennebohm, MD, has the following components:

The Susac Syndrome Consultation Clinic

The Susac Syndrome Consultation Clinic is designed to comprehensively evaluate patients with definite or suspected Susac syndrome. This clinic is staffed by a collaborative multi-disciplinary team of specialists–the Susac Team–which is comprised of neurologists, ophthalmologists, rheumatologists, ENT specialists, audiologists, neuro-ophthalmologists, neuro-otologists, and neuro-radiologists who have developed special interest in Susac Syndrome.

Patients may be referred from anywhere in the United States, or internationally. Patients come to Cleveland Clinic for at least 3-4 days, during which time they attend a series of scheduled outpatient appointments with appropriate members of the Susac Team. After each member of the Team has completed their evaluation, the Team draws its conclusions and shares its recommendations with the patient and the patient’s home physicians.

The Susac Syndrome MyConsult Program

The MyConsult Program is an online second opinion service available to patients who would like the Susac Syndrome Program to review their medical records (and associated MRIs, fluorescein angiograms, and other studies) and offer an opinion regarding diagnosis and treatment. Steps involved:

  • Register securely on the Cleveland Clinic MyConsult website.
  • Select Susac Syndrome as your diagnosis, and fill out the appropriate questionnaires.
  • Collect and send the required medical records and studies to Cleveland Clinic.
  • Once all of this information about your illness has been received, it will be placed in a binder and presented to Dr. Rennebohm, Head of the Susac Team.
  • Dr. Rennebohm and other appropriate members of the Susac Team will thoroughly review the information in the binder (including the actual MRI and fluorescein angiography images) and render an opinion regarding diagnosis and treatment.
  • Dr. Rennebohm will then be available to work with your home physicians regarding your further care.

An online medical second opinion for Susac Syndrome costs $565. The MyConsult Program is designed for patients who may not want to, or are unable to, come to Cleveland to attend the Susac Syndrome Consultation Clinic.

The Susac Syndrome Website at Cleveland Clinic

A fundamentally important component of the Susac Syndrome Program is the development and maintenance of the website you are currently viewing.

This website was designed to provide comprehensive education about Susac Syndrome – for physicians, patients, families, and anyone else interested in Susac Syndrome. Patients who attend the Susac Syndrome Consultation Clinic or access the MyConsult Program are encouraged to read through this website.

Learn more about this site.

The International Collaborative Study (ICS) of Susac Syndrome

Another key component of the Susac Syndrome Program is the research component. The ICS is designed to learn as much as we can from as many patients as possible. Please see the Clinical Research section of this website.

International Education

The Susac Syndrome Program is committed to increasing awareness of Susac Syndrome among physicians throughout the world. Accordingly, Dr. Rennebohm and other members of our Susac Team are available to present information about Susac Syndrome at medical institutions and medical meetings anywhere in the world.

Clinical Study: The International Collaborative Study (ICS) of Susac Syndrome (SuS)

The Cleveland Clinic's Study of Susac Syndrome

The Cleveland Clinic has now launched its new IRB-approved International Collaborative Study (ICS) of Susac Syndrome. Any patient with a diagnosis of Susac syndrome (SuS) is welcome to participate in the Study---including patients who live in countries other than the United States. This Study is being conducted by the Susac Syndrome Research Team at Cleveland Clinic. Robert Rennebohm, MD is the Principal Investigator (PI).

The Purpose of this Study

The purpose of the ICS is to efficiently collect clinical information (both prospectively and retrospectively) on at least 50 current, 50 past and 50 future patients with Susac syndrome, from around the world---so that more can be learned about the clinical features, clinical spectrum, clinical course, treatment needs, long-term outcome, and cause of Susac syndrome.

The ICS is a patient-empowering study, designed to enable patients, themselves, to individually document and collectively submit data about the clinical course and clinical features of their Susac syndrome. In this sense, the patients, individually and as a group, serve as patient-researchers, to collaboratively study their disease.

Short Summary of the ICS

Short Summary of the ICS

There are two separate components to the ICS---the International Disease Registry (IDR) and the Comprehensive Database Project (CDP). It is anticipated that some patients will want to participate in only the IDR and others (we hope all) will want to participate in both the IDR and the CDP:

  • International Disease Registry (IDR): The goal of the IDR is to collect essential, but limited, basic information on as many patients with Susac Syndrome as possible, from around the world. The “basic information” that is collected on the IDR Form and entered into the Registry includes only the following:
    • Patient’s age at time of disease onset
    • Patient’s age at the time of diagnosis
    • Patient’s gender
    • Patient’s country of residence when they developed Susac syndrome (and the state, if the country is the USA)
    • Patient’s home country
    • Ethnicity of patient’s parents
    • Basic characteristics of the patient’s Susac syndrome:
      • Which components of the Susac triad have been involved: brain? eyes? ears?
      • What were the first symptoms?
      • What abnormalities were seen on the brain MRI?
  • The main questions the IDR addresses are:
    • How many patients with Susac's syndrome are there in the world?
    • In which countries do the patients reside?
    • Are certain ethnic groups disproportionately affected? (For example, is Susac syndrome more common amongst people of northern European ancestry, or is it equally common in other population groups? To date, for example, only two patients from India and only a few from China have been reported, suggesting that SuS might be less common in Asian populations.)
    • What clinical features are most commonly experienced?
  • The IDR requires minimal time, effort and commitment on the part of the patient, and no time on the part of the patient’s physicians. The patient or family fills out the IDR Form, as best they can. Our Research Team then confirms the information, based on medical records and images subsequently received from the patient and their physicians.

    The patient must sign a Consent Form before submitting the IDR Form.

    (All these forms may also be found in the Appendix at the end of this Clinical Study section.)

    As soon as our Research Team receives the IDR Form from the patient, the Form is assigned an anonymous code number and entered into the Registry (IDR). No patient identifying information is entered into the IDR. Only Dr. Rennebohm will know the patient associated with the code number for the registered patient.

    Patients will eventually be asked to send (to Dr. Rennebohm) those parts of their medical records (e.g. a CD of their MRI studies, in particular) that will make it possible for Dr. Rennebohm to verify (and correct, if necessary) the information the patient has entered on their IDR Form (and add any missing information).

  • Comprehensive Database Project (CDP): The Comprehensive Database Project collects more extensive and detailed information, than does the IDR. It requires more time, effort, and commitment on the part of the patient.

    For Newly Diagnosed Patients: This project enables, empowers, and encourages all newly (or recently) diagnosed patients to serially fill out a specific set of Data Collection Forms (mostly self-report questionnaires), starting as soon as possible after diagnosis. By “serially,” we mean that they will fill out this set of forms at designated intervals (more frequently, initially, then less frequently) throughout the course of their illness. In this way, the patients will document details of the clinical course and outcome of their disease, including the responsiveness of their disease to various treatments.

    The Data Collection Forms will be filled out on-line, using the REDCap database system (which is explained later in this document). PDF versions of the Data Collection Forms may be viewed by downloading them from the APPENDIX at the end of this document. The PDF versions may be used by the patient and their physicians for their own personal purposes—to keep track of their disease progress.

    For examples of how these Forms are used, and for a demonstration of the value of the Forms, please see the SUPPLEMENT at the end of this Clinical Study section.

    For “Veteran” patients: This project also enables, empowers, and encourages all patients with not-so-recently diagnosed Susac syndrome (even patients who received this diagnosis many years ago) to use some of the same Data Collection Forms to retrospectively capture, reconstruct, and share the details of their experience, including details regarding their long term outcome.

    All patients (both newly diagnosed patients and “veteran” patients) will be asked to send certain portions of their medical records (including MRI images, etc.) to Dr. Rennebohm, who will use that information to complete additional data collection forms on the patient.

The Role of the Patient’s Physicians: For both the IDR and the CDP the role of the patient’s physicians is limited to sending portions of the patient’s medical records to Dr. Rennebohm. The patient’s home physicians do not need to complete any forms for either the IDR or the CDP (though they certainly may, if they wish). They are not serving as co-investigators, and they do not need to obtain approval from their local IRB/ERB (Institutional Review Board/Ethics Review Board) in order for their patient(s) to participate in either the IDR or the CDP. Indeed, out of respect for how busy and over-extended most physicians are, the ICS is deliberately designed to not bother the patients’ physicians. The patients and our Research Team will do the work.

Patients will need to sign a Consent Form before participating in either the IDR or the CDP. It will be clearly indicated on the Consent Form whether they are consenting to participation in the “IDR only” or in both the IDR and the CDP. A copy of the Consent Form may also be found in (and downloaded from) the Appendix. Also, a document regarding the Consenting Process may be found in the Appendix.

For participation in either component, the patient will eventually be asked to send relevant parts of their medical records to Dr. Rennebohm—which, in turn, will require them to sign a Release of Medical Records Form (one provided by Cleveland Clinic and one provided by their home physicians). A copy of the Cleveland Clinic Release of Medical Records Form may be found in (and downloaded from) the Appendix.

We have created a SuS Educational Website (the one you are now viewing) that provides educational information about SuS, explains the ICS, facilitates enrollment of patients from around the world, and provides the Data Collection Forms. A key strategy of the ICS is to enable, empower, and enlist patients to efficiently provide quality data about their experiences with SuS—i.e. this is a patient-driven study and the patients are serving as “patient-clinical researchers.” If a patient needs help in understanding how to accurately fill out the Data Collection Forms, help is available—namely, in addition to our Research Team, several patients who have already experienced Susac syndrome and fully understand how to use the forms are available to serve as “patient clinical research mentors.” If a patient would like to contact such a mentor for help, we can give a mentor’s email address to the patient.  Indeed, this study is designed to enable patients to band together and help each other to study their own disease.

Patients and physicians may access the SuS Website (the one you are currently viewing) for treatment and management guidelines, for the set of Data Collection Forms (in the Appendix), and for directions for participation in the ICS. The Forms, which may be downloaded from this website, were initially designed to help physicians during the day-to-day care of their patients with SuS. They are now being used, also, for research purposes.

IRB Approval

The International Collaborative Study (ICS) of Susac Syndrome has been fully approved by the IRB (Institutional Review Board) at Cleveland Clinic (CCF IRB # 13-188). The complete IRB proposal may be found in the Appendix.

Inclusion and Exclusion Criteria

Patients may participate in the ICS if they have received a diagnosis of definite, probable, or possible Susac syndrome from their personal physician. Patients will be enrolled if they have experienced at least one component of the Susac triad (encephalopathy, retinal vasculopathy, or inner ear disease), if other plausible explanations for their illness have been deemed less likely by their personal physician and by the Principal Investigator’s review of the patient’s medical records, and if the patient has signed formal written consent.

The International Disease Registry (IDR)

The International Disease Registry (IDR) has been established and will be maintained at  Cleveland Clinic.

The goal of the IDR is to collect very basic (see below), but essential, information on as many patients with Susac Syndrome as possible, worldwide.

The "basic information" that will be collected on each patient, and entered into the Registry, is limited to the following:

  • Patient's Age (years and months—for example 33 years, 2 months) when they developed their first symptom(s) of Susac syndrome.
  • Patient's Age (years and months) when they were actually diagnosed with Susac syndrome.
  • Patient's Gender.
  • Patient's  Country of Residence when they developed Susac syndrome (and, the state of residence, if the patient lives in the USA).
  • Patient’s Home country: (The country the patient views as their Home country).
  • Ethnicity of the patient’s mother.
  • Ethnicity of patient’s father.
  • Basic characteristics of Patient’s Susac syndrome (Yes or No answers to the following questions):
    • Has the patient experienced Susac involvement of the brain (e.g. cognitive dysfunction, headache, memory loss, confusion)?
    • Has the patient experienced Susac involvement of the eyes/retina (e.g. scotoma, a dark spot in their vision, BRAO)?
    • Has the patient experienced Susac involvement of the inner ear (hearing loss, tinnitus, or vertigo)?
    • What were the first symptoms?
    • Has the patient had MRI abnormalities characteristic of Susac Syndrome?
      • Did this include lesions in the corpus callosum?

No other data will be collected for the IDR. A specific IDR Form (see Appendix) has been created to capture the above "basic information" and no other patient-related information. All of the IDR Forms will be completed and submitted by the patient—with or without the help of their physicians. Dr. Rennebohm will ultimately verify the data on the Form, based on information he receives from the patient and their physician(s). The above "basic information" on an individual patient, when placed in the Registry, will be identified by only an anonymous code number. Only Dr. Rennebohm will know the patient name that is associated with the code number. The Registry will, therefore, contain no patient identifying information.

It is anticipated that some patients may want to participate only in this IDR component of the ICS and not in the more complicated and time-consuming Comprehensive Database Project (CDP). In such instances the Consent Form will clearly indicate that the patient is consenting to participate only in the IDR component of the ICS. Patients who consent to participate only in the IDR will, however, eventually be asked to send (to Dr. Rennebohm) those parts of their medical records (e.g. a CD of their MRIs) that will make it possible to verify the information entered on the IDR Form. Before sending those records, the patient will need to sign a Release of Medical Records Form (one provided by Cleveland Clinic and one provided by their home physicians).

The goal is to accurately complete an IDR Form on as many patients with Susac syndrome as possible, from around the world—and then analyze the data.

At a later date, Dr. Rennebohm may contact an "IDR only" patient to discuss the possibility of the patient participating in subprojects of the Comprehensive Database Project. At that point, if the patient would like to participate in subprojects of the Comprehensive Database Project, the patient would need to sign a new Consent Form, indicating so.

An IDR Research Information Sheet may be found in the Appendix. This Research Information Sheet explains the purpose of the IDR, emphasizes that no patient-identifying information will be included on the IDR form or be entered into the Registry, lists exactly what information is being recorded on the form, and explains how the patient may participate.

The Comprehensive Database Project CDP

The primary purpose of the CDP is to use a set of Data Collection Forms to capture, document, and study the clinical course and outcome of Susac syndrome, including responsiveness to various treatments.

PDF versions of the Data Collection Forms may be viewed by downloading them from the Appendix at the end of this document. For research purposes, the Data Collection Forms will be filled out (by the patient) on-line, using the REDCap database system (which is explained later in this document). For personal clinical purposes, patients and their physicians are very welcome to use the PDF versions of the Data Collection Forms, to whatever extent they find the Forms helpful.

For examples of how these Forms are used, and for a demonstration of the value of the Forms, please see the Supplement at the end of this clinical study section.

Key strategies of the CDP are:

  • To collect clinical data in a way that does not require the patient’s personal physician(s) to do anything that the physician would not routinely want to do as part of optimal care for a patient with Susac syndrome.
  • To enable and empower newly (or recently) diagnosed patients to capture and share their experience with Susac syndrome—by serially completing a set of self-report forms—that is, newly diagnosed patients will complete a set of Data Collection Forms at many points in time during the course of their illness (more frequently, initially, then less frequently). Please see the document entitled Susac-TimeLine (Susac-TL) in the Appendix. Also, please see the examples provided in the Supplement.
  • To enable and empower “veteran” patients (patients whose diagnosis of Susac syndrome was made many months/years ago) to document and share the status of their disease at several key points in time—e.g. at onset, at the one year mark, and now—with emphasis on the outcome of their disease and its responsiveness to the treatments they received.
  • To enable and empower all patients to provide narrative self-reports and to send relevant parts of their medical records (including CDs of MRIs and fluorescein angiography studies) to Dr. Rennebohm for research purposes (after signing a Consent Form and a Release of Medical Record Form).
  • To have Dr. Rennebohm and the ICS Research Team use the above medical records to complete additional Data Collection Forms, regarding the patient. In this way, the participating patient’s home physicians are not required to fill out any research forms or do any work at all, regarding the ICS. The patients, Dr. Rennebohm, and his staff at Cleveland Clinic do all of the research work of the ICS. The patient’s physicians are free to concentrate entirely and only on providing optimal patient care. Their only responsibility is to facilitate the sending of the medical records that their patient asks them to send (and signs consent for them to send) to Dr. Rennebohm.

The patient’s physician is not serving as a co-investigator and is not filling out forms for research purposes. Accordingly, the patient’s physician does not need to obtain local IRB/ERB approval for the patient’s participation in the study. Again, the role of the patient’s physician is simply to agree to send the patient’s medical information (e.g. consultation notes, hospital notes, clinic notes, lab results, MRI, fluorescein angiography, and audiograms) to the Study’s Principal Investigator (Dr. Rennebohm)—at the formal signed request of the patient. The participating patient signs the same “Release of Medical Records” form that their physician routinely asks patients to sign when a patient requests that their records be sent to another physician. In addition, the patient will sign the Cleveland Clinic Release of Medical Records form (and FAX or otherwise send it back to us). Because the patient’s physician is simply sending the patient’s records and is not otherwise participating in research, local IRB approval is not necessary.

The Comprehensive Database Project (CDP) involves use of several Data Collection Forms (see Appendix). These Forms were developed by Dr. Rennebohm for routine clinical use by physicians and patients—to facilitate and improve the week-to-week and longer-term care of patients with Susac syndrome. Over the years physicians and patients have found these forms useful to them—in that serial use of these forms (and the scores they generate) provide an easier, more efficient, and more accurate way to follow the progress of an individual patient and to make decisions regarding that patient’s treatment. The Forms are particularly helpful if use of them is started at the time of diagnosis or at the onset of treatment. See Supplement for an example of the value of using these forms.

Physicians and patients may download PDF versions of these Forms (from the Appendix) for their personal use, even if they are not participating in the ICS. The physician, the patient, or both, may use them (e.g. the Medication Flow Sheet and the Susac-Symptoms Form,  and possibly the Susac Da-GA and Susac-PAM) in the routine week-to-week, month-to-month care of the patient. Accordingly, completion of these Forms may become part of some patient’s routine care, and in those cases the Forms become part of the patient’s medical record. This is modeled after Dr. Rennebohm’s development of the CMAS (Childhood Myositis Assessment Scale) to facilitate and improve the routine clinical care of juvenile dermatomyositis (JDM). The CMAS is now routinely used by many pediatric rheumatologists, in their routine day-to-day care of children with JDM. After many years of being used simply and only for clinical care purposes, the CMAS eventually became an important research tool and is now used in most clinical studies of JDM. Similarly, the HAQ (Health Assessment Questionnaire) has become routinely used by many rheumatologists—both as part of their day-to-day clinical care of patients with rheumatoid arthritis and as a research tool.

The majority of the Forms used in the Comprehensive Database Project are designed as patient/family self-report forms. This was purposefully done, because it was anticipated that patients/families would be highly motivated to use them, and physicians might feel too busy to use the forms. We wanted use of the forms to be a patient-driven effort. The main forms the physician might want to consider using (for clinical care purposes) are the Medication Flow Sheet and the physician versions of the Susac-Symptoms, Susac DA-GA, and Susac PAM Forms. When patients elect to participate in the Comprehensive Database Project, they are encouraged to take the initiative of serially using the patient self-report forms and sharing the results with their physicians.

Although the forms used in the Comprehensive Database Project were initially developed for the purpose of facilitating and improving routine week-to-week clinical care of individual patients, they will now serve to generate clinical data for research purposes—just as the data from clinical use of the CMAS and HAQ have been used for clinical research purposes for JDM and rheumatoid arthritis. Many of the forms (e.g. the Susac-CML and Susac-Medication Flow Sheet, in particular) can be filled out retroactively by the patients and by the Principal Investigator of the ICS, based on information in the patient’s medical records.

A suggested TimeLine (Susac-TL) is provided in the Appendix to indicate when (at what times during the patient’s course) it is helpful for the physician/patient/family to complete the forms and obtain the various evaluations—for the sake of providing efficient and optimal care. If a patient’s physician elects to provide care for the patient without use of any CDP forms, that is okay. In such instances, Dr. Rennebohm, for research purposes, will do his best to retrospectively complete these forms, based on medical records he receives from the patient.

To facilitate management of their own patient, physicians are encouraged to maintain the Susac Medication Flow Sheet. The patient and family may also want to maintain this flow sheet, so that they can optimally keep track of the patient’s treatment.

How will participating patients access, complete and submit the Data Collection Forms?

Data collection will be accomplished by using the REDCap Database System.

REDCap stands for Research Electronic Data Capture.  It is a secure, web-based application for building databases and managing online questionnaires/surveys. We will help all enrolled patients learn how to complete and submit their forms via REDCap. Here is how the REDCap system works:

The patient will receive an email from REDCap. The email will contain a link to REDCap that will enable the patient to access a specific blank Data Collection Form. The patient completes the Form on line and clicks the submit button. Their completed Form is then automatically filed in their personal secure file, which is identified only by their personal anonymous Patient ID #. At scheduled times (see Susac—TimeLine, Susac-TL), a new email message is sent to the patient to enable them to again access REDCap to complete and submit a new form.

We think patients will quickly recognize that the REDCap system is an excellent way for them to complete and submit Data Collection Forms. It is the easiest, most secure, most confidential, most efficient, least expensive, and most organized way for patients to complete and submit their forms.

Patients who are unable to use the REDCap system, may download the PDF versions of the forms from the Appendix, fill them out, and either mail, FAX (216 445 1035), or Save-as-an-Attachment-and-Email or Scan-and-Email the forms to:

The Consenting Process

If a patient would like to participate in the ICS (either the IDR alone, or the IDR and the CDP), or wants more information, how does he/she go about doing so?

In the Appendix please find and read the Consenting Process, for complete details. Below is an outline of the process:

The first step is to email Dr. Rennebohm (at: to indicate your interest in participating in the ICS.

Dr. Rennebohm (or a member of our Research Team) will be happy to discuss the IDR and CDP with you (by email, or by phone, or both) and answer any questions you may have.

Once you decide to definitely participate in the ICS, the next steps are:

  • Sign a Consent Form:
    • You can download the Consent Form (and the explanation that accompanies it) from the Appendix; or you can ask Dr. Rennebohm to email the Consent Form to you.
    • Note that there is a checkbox within the consent form that allows you to indicate whether you are consenting to participate in only the IDR or the IDR and the CDP.
    • Note that the Consent Form can be filled out on line, except for the need to provide your actual signature.
    • On the day you officially sign the Consent Form, it will be necessary for Dr. Rennebohm (or an ICS research team member) to have a phone conversation with you to verbally document that you feel fully informed (verbally) about the ICS and are signing the consent form after being fully informed. This is a strict IRB rule.
  • Send the Consent Form:
    • After signing the Consent Form, you can mail, FAX, or scan-and-email it to Dr. Rennebohm
    • FAX #: 216 445 1035
    • Email Address:
    • Mail Address:
      Rob Rennebohm, MD
      Director, Susac Syndrome Consultation Services
      Crile Bldg, Desk A111, Attn: Janica Petty
      Cleveland Clinic
      9500 Euclid Ave.
      Cleveland, OH, USA 44195
  • Sign the Release of Medical Records forms—one from the Cleveland Clinic (see Appendix) and one from your home physician(s). You can mail, FAX, Save-and-Email-as-an-Attachment, or scan-and-email a copy of the Cleveland Clinic form to Dr. Rennebohm. You do not need to send your home physician’s form to Dr. Rennebohm.
  • Upon receipt of your signed Consent Form, Dr. Rennebohm will create a Secure Confidential Patient Enrollment File for you. Only Dr. Rennebohm will have access to this File. It will contain:
    • Your name, date of birth, home address, phone number, email address.
    • Your assigned anonymous ICS Patient ID number.
    • Checkboxes that indicate that we have received your signed Consent Form and signed Cleveland Clinic Release of Medical Records Form. Checkboxes will also indicate whether you have requested to participate in only the IDR or in both the IDR and the CDP.
    • Your actual signed Consent Form and Cleveland Clinic Release of Medical Records Forms will be scanned and saved in this File.
  • By this time you should be sure to have notified your home physician(s) that you have decided to participate in the ICS.
  • The next step is to ask your home physician(s) to send a brief email to Dr. Rennebohm so that Dr. Rennebohm can establish email correspondence with your home physician(s), regarding the ICS.

After the above has been accomplished:

  • Dr. Rennebohm will email you to explain the top priority information he needs from you---e.g. a completed IDR Form and a CD that contains all of your MRI images. (The CD of MRIs can be obtained by going to the Radiology Department that performed the study and asking them to “burn” your MRI studies onto a CD. They usually charge only a small fee for this service. The IDR Form will be sent to you via REDCap.)
  • Dr. Rennebohm will email the patient’s home physician(s) to:
    • Explain that their patient has chosen to participate in Cleveland Clinic’s IRB-approved International Collaborative Study (ICS) of Susac Syndrome and has signed a Consent Form to do so.
    • Encourage the physicians to review the Cleveland Clinic’s Susac Educational Website, especially the Clinical Study section that describes the ICS.
    • Explain and emphasize that the patient’s home physician(s) need not obtain local IRB approval in order for the patient or their home physicians to participate in the ICS.
    • Encourage the home physicians to use the Data Collection Forms to the extent to which they might find them helpful in their routine care of the patient---but, at the same time, it will be emphasized that use of these forms is completely optional.
    • Encourage the home physician to comply with the patient’s formal, signed request (and right) to have portions of their medical records sent to ICS Headquarters.
    • Request that a CD of the patient’s initial MRI (and all subsequent MRIs) be sent (by the physician or by the patient) to the ICS Headquarters (to the PI of this study).
    • Request that the initial (and all subsequent) ophthalmologic reports be sent to ICS Headquarters. These reports will include the ophthalmologist’s routine report, plus reports of a visual field and OCT studies. If fluorescein angiography (FA) is done, the headquarters would like to have the official report and a CD of each entire FA study.
  • Dr. Rennebohm will verify the patient-completed IDR Form, based on additional information he receives from the patient and the patient’s home physician(s).
  • Dr. Rennebohm (or a member of our Research Team) will then help the patient get started with further Data Collection Forms (if the patient is participating in the CDP), using the REDCap system.

We would like to emphasize that patients may participate in the ICS to whatever extent they wish. They may participate in only the IDR component, or in both the IDR and the Comprehensive Database Project. If they participate in the CDP, they may do so minimally, maximally, or anywhere in-between.

Collection of Medical Records of Patients from throughout the World:

Individual patients who wish to participate (to any degree) in the ICS (either the IDR alone or the IDR and CDP) will be asked (after signing the Consent Form) to request that portions of their medical records be sent to the ICS Headquarters—for research purposes—so that details of their clinical experience with Susac syndrome can be made available to Dr. Rennebohm and his team of investigators.

The patients will explain to their physicians that they have signed a Consent Form to participate in the ICS and that the patient now wishes to have certain parts of their medical records sent to ICS Headquarters at Cleveland Clinic—for clinical research purposes. The patient’s home physician(s) may send the patient’s medical records by simply having the patient sign the “Release of Medical Records” form that the physician’s office/institution routinely uses when patients ask for their records to be sent to another physician or institution.

The medical records that the patient and their physicians will be encouraged to send (in order of priority) include:

  • CD of all MRIs
  • CD containing all FA studies (or at least the initial and most recent FA study)
  • Initial Consultation Notes (e.g. from Neurology, Ophthalmology, ENT, Audiology, Rheumatology)
  • Hospitalization summaries (including admission and discharge notes)
  • Subsequent Clinic Notes of the neurologists, ophthalmologists, ENT specialists, and other physicians involved in the on-going care of the patient’s Susac syndrome
  • Copies of the results of visual field exams and OCT studies
  • Copies of audiograms and any vestibular studies
  • Brain biopsy reports (if biopsy has been done)
  • Copies of any of the ICS Data Collection Forms that the patient or physician may have used as part of the patient’s routine clinical care

Once the above medical records have been received by Dr. Rennebohm, they will be de-identified, and then studied by the ICS investigators (Dr. Rennebohm and team) to document details of the patient’s clinical experience with Susac syndrome. The data will be collated and stored in a secured fashion that ensures protection of patient confidentiality and privacy—using an anonymous code number for each patient.

CPD Sub Projects

Study of the Spectrum, Clinical Course, Responsiveness to Treatment, and Outcome of Susac Retinal Vasculopathy—A CDP Sub-project:

A major feature of Susac syndrome is retinal vasculopathy (autoimmune microvascular endotheliopathy in the retina). The clinical features of Susac retinal vasculopathy include: scotoma, cotton wool spots, “vessel wall hyperfluorescence”,  “leakage”,  varying degrees of branch retinal artery occlusion (BRAO), capillary dropout, microaneurysms, neovascularization, and vitreous hemorrhage. The nature of this retinal vasculopathy is best revealed by fluorescein angiography (FA). Color retinal photos, OCT and visual field studies also reveal abnormalities.

There is a paucity of information regarding the clinical spectrum of Susac retinal vasculopathy—particularly the natural history, responsiveness to treatment, clinical course, and long-term outcome of Susac retinal vasculopathy. For example, we do not have proven answers to the following questions:

  • When a patient develops a partial or complete BRAO, how much immunosuppressive treatment is needed and for how long? How often is sufficient blood flow restored, and if so, how long does it take to do so?
  • When BRAO develops, does the size of the vessel matter? Is BRAO in a proximal branch retinal artery more threatening than BRAO in tiny vessels out in the far periphery?
  • How soon can immunosuppressive therapy reverse vessel wall hyperfluorescence and leakage? How much long-term immunosuppression is needed to prevent relapse of vessel wall hyperfluorescence, leakage, and BRAO?
  • Is vessel wall hyperfluorescence and leakage always a sign of active immune attack on the vessel? Or, can previously damaged vessels that are no longer experiencing any active immune attack, leak and become hyperfluorescent (simply because of the past damage they sustained)?
  • For how many months or years can an individual patient continue to experience recurrent episodes (clinical or subclinical) of Susac retinal vasculopathy (active immune attack on the microvasculature)? How frequently do such episodes usually occur (how many episodes per year)? Do some patients experience chronic constant continuously active Susac retinal vasculopathy for months/years (as opposed to only intermittently active disease)?
  • What is the long-term outcome of Susac retinal vasculopathy?
    • How severe is the long-term visual impairment—from both the patient’s perspective and the ophthalmologist’s perspective?
    • How many patients develop irreversible damage—e.g. microaneurysms, neovacularization, capillary dropout, vitreous hemorrhage, permanent visual field loss?
    • What do serial OCT studies reveal?
  • What is the role of ultra-wide field fluorescein angiography (Optos) in the evaluation and long-term management of Susac retinal vasculopathy?
  • How is Susac retinal vasculopathy best treated?

To address these questions we will be studying the ophthalmologic evaluations performed on all patients who have agreed to participate in the ICS. This will involve study of FA images sent by patients/physicians.

Long-Term Outcome of Susac Syndrome—A CDP Sub-project:

Little is known about the long term outcome of patients who have had SuS. By “long term outcome” we mean the status of patients 5, 10, 20, 30 years after onset of their disease.

What are patients whose SuS was diagnosed 3, 5, 10, 20, or 30 years ago, now experiencing?

  • How much irreversible damage has the disease caused?
  • How well are patients functioning cognitively?
    • How much memory deficit?
    • How much impairment of “executive function?”
    • How much impairment of thinking ability, thought-processing?
  • How well are they functioning physically?
    • How much difficulty do they have carrying out ordinary Activities of Daily Living (ADL)
    • Have they developed spasticity? To what degree?
    • Have they developed bladder dysfunction? To what degree?
  • What has their “Quality of Life (QOL)” been since experiencing SuS?
  • To what extent did their experience with SuS necessitate vocational changes or adaptations?
  • How are they doing emotionally?
  • What has been the effect of their SuS on their marriage and family life?
  • How much irreversible visual disturbance?
  • How much irreversible hearing loss?

Only limited formal studies of the long-term outcome of SuS have been conducted. The one long-term outcome study that has been published does not include formal neurocognitive or quality of life evaluations (Aubart-Cohen, 2007).

In this Sub-Project, patients will be asked to complete a set of outcome questionnaires to indicate how they are currently doing, and they will be asked to retroactively complete some of those same questionnaires to indicate how they were doing at several different points of time in the past (for example, at the time of diagnosis and at the one year mark). These questionnaires will include:

  • Susac-Symptoms Form
  • Susac-Disease Damage Score (DDS)
  • Susac-HL, Susac-Mini-T, Susac TSAS
  • Susac-Quality of Life (QOL) Questionnaire
  • Susac-HAQ Functional Status Questionnaire
  • Susac-NEI VFQ-25 (Visual Function Questionnaire)
  • Vocational Status Questionnaire
  • Susac-Current Medications
  • Susac-Cumulative Medications

In addition, the following studies will also be obtained to document their current status:

  • Formal visual field, OCT, and FA testing
  • Formal audiometry evaluation
  • Formal, extensive neuro-cognitive testing (if possible), or Susac-SAGE
  • Current or most recent MRI

Clinical Course Graphs:Some willing patients will also be asked to retrospectively draw a free-hand graph of the clinical course of their Susac illness—one graph to depict the level of active disease in the brain over time; one to depict active ophthalmologic involvement, one for hearing loss, and one for tinnitus. These free-hand graphs will be filed in a Compendium of SuS Free Hand Clinical Course Graphs and will be compared to other clinical course data generated by the SuS-ICS. This Compendium will provide many examples of how the SuS of individual patients has behaved over time.

Qualitative research: Some willing patients and families will be interviewed about their experiences with SuS, so that we can hear their voices and document and study what they have to say.

Susac Syndrome and Pregnancy—A CDP Sub-Project:

Several patients with Susac syndrome have first developed their Susac syndrome during a pregnancy. Others have developed their Susac syndrome during the post-partum period. Others have experienced relapses of their Susac syndrome either during a subsequent pregnancy or subsequent post-partum period. As far as we know, all patients with Susac syndrome who have eventually had babies have had perfectly normal babies.

We need more data to determine what percentage of patients with Susac syndrome experience initial disease during either pregnancy or the post-partum period; what percentage of those patients (or other patients) experience relapse during a subsequent pregnancy or post-partum period; how severe are the relapses when they do occur; and what percentage of the babies born in the context of Susac syndrome are perfectly normal?

Data will be collected to better answer these and related questions about Susac syndrome and pregnancy.

Retrospective and Prospective Study of SuS in Children and Adolescents—A CDP Sub-project:

Only a few cases of SuS in children/adolescents have been reported in the international medical literature. It is likely, however, that SuS has been under-diagnosed and under-reported in children, as well as adults. Many pediatricians, including pediatric rheumatologists, ophthalmologists, and neurologists, have either never heard of SuS or are minimally aware of it. Most have never seen a case.

The primary objectives of this sub-study are:

  • To survey the international pediatric rheumatology community, the pediatric ophthalmology community, and the pediatric neurology community (via professional List Serves) to determine how many cases of pediatric SuS have been noted by members of these medical communities.
  • To retrospectively collect and analyze data on the patients so identified, with particular attention to:
    • Clinical characteristics at the time of diagnosis
    • Treatment, including response to various treatments
    • Clinical course: monocyclic, polycyclic, or prolonged continuous?
    • Outcome
  • Comparison of SuS in children vs. SuS in adults
  • To increase physician awareness of SuS in children

Retrospective Study of Treatment of SuS with IVIG, Rituximab, or both—A CDP Sub-project:

The current recommendations for treatment of SuS are based on the treatment of juvenile dermatomyositis (JDM)---a better known and more extensively studied autoimmune microvascular endotheliopathy disorder. The immunosuppressive therapies that have routinely been used for, and have greatly benefitted patients with, JDM have included oral prednisone, pulses of methylprednisolone, IVIG, methotrexate, mycophenolate mofetil, and cyclophosphamide. These same therapies have appeared to greatly benefit patients with SuS.


IVIG is a particularly important treatment option for SuS. It has the best benefit/risk ratio of any therapy used for SuS. Unfortunately, IVIG is very expensive and many insurance companies and governments are unwilling to cover the cost of IVIG treatment—particularly, since there are no formal published studies of a large number of patients that show that IVIG is effective for SuS. It is imperative, therefore, that we collect data regarding the effectiveness of IVIG for SuS.


The most recently studied new therapy for JDM has been rituximab---an anti-CD20 B cell antibody. Rituximab has been shown to be a promising therapy for a number of autoimmune diseases, including rheumatoid arthritis, lupus, Sjogren’s syndrome, ITP, and autoimmune hemolytic anemia, and multiple sclerosis---as well as juvenile and adult dermatomyositis.

Because rituximab appears to be a promising option for treatment of dermatomyositis, it has been recommended and used as a reasonable innovative option for treatment of SuS (2-4).

Dr. Rennebohm has become aware of at least 15 physicians who have opted to treat SS with rituximab. They and their patients have usually chosen this option because they have viewed it as a less risky alternative to cyclophosphamide and because rituximab has shown potential as a steroid sparing agent. In some instances the rituximab has been added to cyclophosphamide because of the extreme severity/intensity of the disease. Dr. Rennebohm’s subjective impression is that the patients (and their physicians) who have used rituximab believe it has been effective in the majority of, but not all, cases. Since rituximab is increasingly being used for a variety of autoimmune diseases, including dermatomyositis and SuS, it is important to conduct a formal retrospective study to determine the extent to which rituximab has benefited patients with SuS. This would be the first study of rituximab in the treatment of SuS.

To determine whether rituximab is worthy of inclusion in any future clinical trial of treatment for SuS, it is obviously important to retrospectively and systematically study patients with SuS who have already been treated with rituximab.

Bio-Bank Projects—A CDP Sub-project:

In addition to studying clinical aspects of Susac syndrome, an important component of the ICS is the collection of research samples for the analysis of novel biomarkers that may potentially aid in either the diagnosis of Susac syndrome, assessment of disease activity, or understanding of the immunopathogenesis of SS.

The Consent Form will provide an option for blood draws for biomarker analysis, and will seek permission to store any unused cerebral spinal fluid (CSF) from clinical samples for future analysis. Specimens will be collected and processed into either 0.5 ml or 1.0 ml aliquots, boxed, and stored in a minus 70 degree C freezer on site. Funding will be supported by the Fasenmyer Center at Cleveland Clinic.

The potential biomarkers that we are interested in studying include:

  • Circulating endothelial cells (CECs), which is a reliable marker of vascular injury.
  • Endothelial microparticles (MPs), which are potential prognostic markers for endothelial injury.
  • Anti--Endothelial Cell Antibodies (AECA).
  • Soluble fms-like tyrosine kinase-1(sFlt-1), also known as soluble VEGF receptor.
  • Calcitonin gene-related peptide (CGRP).
  • Biomarkers implicated in the pathophysiology of cerebral vasospasm.
  • Exploratory genetic and proteomic studies (with isolation of plasma, DNA, and c-DNA).

The above biomarker and genetic studies will be done in conjunction with already existing studies being conducted by Rheumatology (Drs. Calabrese and Hajj-Ali) and Ophthalmology (Dr. Srivastava) at Cleveland Clinic.

We will also be establishing a brain biopsy bank: Some patients who enroll in the ICS will have had brain biopsies. With the consent of these patients, we will request their biopsy materials for study.

Statistical Analysis

Our goal is to collect data on as many patients with SuS as possible, from around the world. Since the prevalence and incidence of SuS is unknown, the true number of patients with past, current, or future SuS is unknown. Given this uncertainty and the paucity of scientifically sound information about SuS, there is no a priori comparison or effect size to look for, and, as such, no usual power calculation or sample size calculation can be provided. Under the expectation of accumulating at least 150 patients, even if split into 3 groups, information on the accuracy of some descriptive estimators of outcomes can be presented: In the case of dichotomous variables, the proportions will have a corresponding 95% confidence interval with a margin of error of 0.15 in the worst case scenario. For continuous variables, given the lack of information on variability associated with them, 50 subjects allow for normal theory approximations to work.

In this first phase of the project we aim to collect enough data to be in a position to look at possible patterns present in the disease and its course. At this stage we will be performing descriptive exploratory analyses on the main outcomes by other variables of interest such as demographics and courses of treatment to obtain a picture of what has happened with the disease to date. In this sense, usual summary descriptors such as means, medians, standard deviations, interquartile ranges, proportions, and graphical summaries such as boxplots, scatterplots, and time series will be used to gain knowledge about the disease. There are some a priori hypotheses regarding effects of treatments on outcomes—however, until we obtain a clear picture that will inform us of the uniformity or variability of treatments used, we will not be able to define comparison groups for statistical analysis. Hence, this first phase is crucial for setting up future further hypotheses and statistical analyses.

Privacy Protection

The database product that will be used to obtain and store data will be REDCap. All computers used will be encrypted and password protected. The SuS Research Team at the Cleveland Clinic will be responsible for maintaining the computer system and entering and maintaining the data. Sub-investigators will be able to obtain data only through the permission of the Principal Investigator.

All study material will be coded with a participant ID number. The key for the participant ID number and the corresponding participant name will be stored (in the Secure Confidential Patient File) within the computer used for the study. All files will be triple password protected. Back-up disks for the system will be stored in a locked filing cabinet. Following analysis, all data will be stored in disks and given to the Principal Investigator for confidential secured storage.

In the event that patient information in this registry is to be shared (for research purposes) with any colleagues outside of Cleveland Clinic, all patient identifiers will have been removed—such that the only identifier of the data is the code ID number.

Interactions with Patients

Patients who wish to participate in the ICS may find all instructions on the SuS-Website and in the Appendix at the end of this section. They may also download the Consent Form, the IDR Research Information Sheet, and all Forms (and their instructions) from the website. In many of our communications with patients, we will simply refer them to the website.

On other occasions we will be communicating with patients via email.

Informed Consent

All participants in the ICS must sign a written Consent Form (also see APPENDIX).


Greco A, De Virgilio A, Gallo A, Fusconi M, Turchetta R, Tombolini M, Rizzo MI, de Vincentiis M. Susac's syndrome--pathogenesis, clinical variants and treatment approaches. Autoimmun Rev. 2014 Aug;13(8):814-21.

García-Carrasco M, Mendoza-Pinto C, Cervera R. Diagnosis and classification of Susac syndrome. Autoimmun Rev. 2014 Apr-May;13(4-5):347-50.

Dörr J, Krautwald S, Wildemann B, Jarius S, Ringelstein M, Duning T, Aktas O, Ringelstein EB, Paul F, Kleffner I. Characteristics of Susac syndrome: a review of all reported cases. Nat Rev Neurol. 2013 Jun;9(6):307-16.

Kleffner I, Duning T, Lohmann H, Deppe M, Basel T, Promesberger J, Dörr J, Schwindt W, Ringelstein EB. A brief review of Susac syndrome. J Neurol Sci. 2012 Nov 15;322(1-2):35-40.

Mateen FJ, Zubkov AY, Muralidharan R, Fugate JE, Rodriguez FJ, Winters JL, Petty GW. Susac syndrome: clinical characteristics and treatment in 29 new cases. Eur J Neurol. 2012 Jun;19(6):800-11.

Papo T, Klein I, Sacré K, Doan S, Bodaghi B, Aubart-Cohen F. Susac syndrome. Rev Med Interne. 2012 Feb;33(2):94-8.

Roeser MM, Driscoll CL, Shallop JK, Gifford RH, Kasperbauer JL, Gluth MB. Susac syndrome--a report of cochlear implantation and review of otologic manifestations in twenty-three patients. Otol Neurotol. 2009 Jan;30(1):34-40.

Susac JO, Egan RA, Rennebohm R: Susac's Syndrome 1975–2005: Microangiopathy/autoimmune endotheliopathy. J Neurol Sci 2007, 257:270-272. PubMed Abstract | Publisher Full Text |

Rennebohm R, Susac JO: Treatment of Susac's syndrome. J Neurol Sci 2007, 257:215-220. PubMed Abstract | Publisher Full Text |

Rennebohm RM, Egan RA, Susac JO: Treatment of Susac's syndrome. Curr Treat Options Neurol 2008, 10:67-74. Publisher Full Text |

Rennebohm RM, Lubow M, Rusin J, Martin L, Grzybowski D, Susac JO: Aggressive Immunosuppressive treatment of susac’s syndrome in an adolescent---Using treatment of dermatomyositis as a model. Pediatric Rheumatology 2008, 6:3. This article may be accessed via:

Hahn JS, Lannin WC, Sarwal MM: Microangiopathy of brain, retina, and inner ear (Susac's syndrome) in an adolescent female presenting as acute disseminated encephalomyelitis. Pediatrics 2004, 114:276-281. PubMed Abstract | Publisher Full Text |

Muttikkal THE, Vattoth S, Chavan VNK: Susac syndrome in a young child. Pediatr Radiol 2007, 37:710-713. PubMed Abstract | Publisher Full Text |

Fox RJ, Costello F, Judkins AR, Galetta SL, Maguire AM, Leonard B, Markowitz CE: Treatment of Susac syndrome with gamma globulin and corticosteroids. J Neurol Sci 2006, 251:17-20. PubMed Abstract | Publisher Full Text |

Heiskala H, Somer H, Kovanen J, Poutiainen E, Karli H, Haltia M: Microangiopathy with encephalopathy, hearing loss and retinal arteriolar occlusions: two new cases. J Neurol Sci 1988, 86:239-250. PubMed Abstract | Publisher Full Text |

Kaminska EA, Sadler M, Sangalang V, Hoskin-Mott A: Microangiopathic syndrome of encephalopathy, retinal vessel occlusion, and hearing loss. Can J Neurol Sci 1990, 17:241.

Petty GW, Engel AG, Younge BR, Duffy J, Yanigahara T, Lucchinetti CF, Bartleson JD, Parisi JE, Kasperbauer JL, Rodriguez M: Retinocochleocerebral vasculopathy. Medicine 1998, 77:12-40. PubMed Abstract | Publisher Full Text |

O'Halloran HS, Pearson PA, Lee WB, Susac JO, Berger JR: Microangiopathy of the brain retina, and cochlea (Susac's syndrome): a report of five cases and a review of the literature. Ophthalmoscopy 1998, 105:1038-1044. Publisher Full Text |

Crowson AN, Magro CM: The role of microvascular injury in the pathogenesis of cutaneous lesions of dermatomyositis. J Human Pathol 1996, 31:515-519.

Rennebohm R: Juvenile dermatomyositis. Pediatr Ann 2002, 31:426-433. PubMed Abstract

Fisler RE, Liang MG, Fuhlbrigge RC, Yalcindag A, Sundel RP: Aggressive management of juvenile dermatomyositis results in improved outcome and decreased incidence of calcinosis. J Am Acad Dermatol 2002, 47:505-511. PubMed Abstract | Publisher Full Text |

Aubart-Cohen F, Klein I, Alexandra J-F, Bodaghi B, Doan S, Fardeau C, Lavallee P, Piette J-C, Hoang PL, Papo T: Long-term outcome in Susac syndrome. Medicine 2007, 86:93-102. PubMed Abstract | Publisher Full Text |

Susac JO, Murtagh FR, Egan RA, Berger JR, Bakshi R, Lincoff N, Gean AD, Galetta SL, Fox RJ, Costello FE, Lee AG, Clark J, Layzer RB, Daroff RB: MRI findings in Susac's syndrome. Neurology 2003, 61(12):1782-1787. PubMed Abstract |

Egan RA, Nguyen TH, Gass DM, Rizzo JF, Tivnan J, Susac JO: Retinal arterial wall plaques in Susac's syndrome. Am J Ophthalmol 2003, 135:483-486. PubMed Abstract | Publisher Full Text |


Below are PDF versions of the Data Collection Forms that will be used in the ICS. All of these PDF versions have virtually identical REDCap versions that are imbedded within the REDCap system. The REDCap versions, that patients will be completing on line when they receive their emails from REDCap, are “cleaner,” prettier, and easier to complete and submit on-line, than are the PDF versions. 

For research purposes, patients will complete and submit forms via the REDCap system. For clinical care purposes, patients and physicians are very welcome to use the PDF versions (below) for their own personal use. Most of the PDF versions can be completed on line; some (those with 10 cm visual analog scales) must be printed out and completed by hand.

If a patient/family would like help in understanding how to correctly use any of the forms, they are welcome to contact our Research Team (—or, we can connect them with one of several patients who are very familiar with use of these forms (including use of the REDCap system) and are willing to serve as “Mentors for Patient-Researchers.”

IDR Form:

CDP Data Collection Forms:

Top Priority Forms:

Lower Priority Forms:



Examples Regarding the Use and Value of the Disease Assessment Forms

To exemplify use of some of the most important Forms of the ICS, and to demonstrate the value of using them, we are sharing Forms that were completed by an actual patient. To preserve the anonymity and privacy of the patient, we have eliminated all patient-identifying information, and we have changed the dates. The patient/family has gladly given us permission to use the patient’s history and their completed Forms for demonstration and teaching purposes. Again, the dates in the history have been purposefully changed.

First, a Summary of the Patient’s Story:

The patient was well until 12/16/13 when she developed numbness and tingling near her mouth and lips and in her hands/fingers. She had also become tired, and was beginning to forget things, often “failing to follow-up on things.”

The above symptoms continued. Then, on 12/30/13 she developed more dramatic and obvious behavioral abnormalities. She became inappropriately giddy and giggly. She seemed unaware of how abnormal she was behaving. Soon she became somewhat incoherent. These symptoms prompted a 911 call and admission to the hospital on 12/31/13. On admission, the following symptoms were evident:

  • Headaches, with vomiting
  • Decreased mental alertness, slow thought processing
  • Short term memory problems
  • Confusion, disorientation, odd behaviors, compromised insight regarding her condition
  • Decreased executive function (disorganized, not able to take care of her affairs or make good decisions)
  • Personality change
  • Emotional lability (giddiness, inappropriate giggling)
  • Marked inability, intellectually, to do her usual work
  • Numbness and tingling (paresthesias)
  • Difficulty walking
  • Imbalance
  • Bladder dysfunction
  • Apraxia (unable to figure out how to do things that she used to do automatically)
  • Vertigo
  • She had no hearing loss or tinnitus (vertigo was her only inner ear symptom)
  • She had no convincing visual symptoms (no scotoma)

On 12/31/13 an MRI revealed several “snowball” lesions in her corpus callosum, as well as several scattered smaller lesions elsewhere in her white matter. (Her MRI looked very much like those shown on this website.) 

Although her diagnosis was unclear at that time, she was treated with 4 consecutive daily pulses of methylprednisolone (1000 mg each), from 1/1/14 through 1/4/14. (See Medication Flow sheet). She improved considerably and rapidly (thanks to the pulses). On 1/5/14 she was discharged, on oral prednisone 60 mg each day.

She continued to improve on a daily basis until 1/10/14 when many of her symptoms again worsened. This prompted re-admission, further evaluation, and further treatment. A fluorescein angiogram (FA) revealed multiple branch retinal artery occlusions (BRAO). A repeat MRI showed new lesions. At this point a definite diagnosis of Susac syndrome was made. Over the next 8 days (1/15-1/22) she received 6 pulses of methylprednisolone, 2 gm/kg IVIG, and was started on Cellcept (mycophenolate mofetil). During this time she improved and stabilized---though a repeat FA study on 1/26 showed new active disease in her retina (since the initial study). On 1/27/14 she was started on rituximab.

Her clinical course since then is depicted by the data on her Susac Symptoms Serial Scores (Example SSS 1-3) and on her Susac Syndrome Medication Flow Sheet (Example MED 1-4). In addition, Example Symptoms A and Example Symptoms B show the actual data entered on the Susac Symptoms form at two different times---time zero (12/31/13) and 17 weeks later (4/29/14).

Comments about the Data on the Forms

Susac Syndrome Medication Flow Sheet:

The Medication Flow Sheet shows exactly what immunosuppressive medications the patient received from onset of treatment through 5/16/14---including the doses and exact dates. The Instructions for use and interpretation of this Flow Sheet may be found in the document entitled “MED Instructions.” Note that this patient has primarily been treated with prednisone, pulses of methylprednisolone, IVIG, Cellcept, and rituximab. Although the option of cyclophosphamide was considered, it was decided to use Cellcept instead. Note that the use of pulses and IVIG was a bit atypical in her case---in that for a period of time she received IVIG once per week, then every 10 days, with an accompanying lower dose of pulse methylprednisolone (250 mg, or 500 mg, rather than 1000 mg).

Susac Symptoms:

Examples A and B show the patient’s actual individual Susac Symptoms scores at time zero (12/31/13, before onset of any treatment) and 17 weeks later (4/29/14). Note that on a scale of 0 to 100---with 0 meaning no symptom and 100 meaning an extremely severe degree of that particular symptom---the patient’s scores for each of the 13 neurologic symptoms were quite high on 12/31/13. For example, her scores for decreased mental alertness, headache, memory impairment, and confusion were 62, 51, 96, and 61, respectively, and the average score for the 13 neurologic symptoms was 69.1. On 4/29/14 those same scores were 4, 0, 2, and 0, respectively, and the average score for the 13 neurologic symptoms was only 1.5---documenting marked improvement.

Note that since the patient was within the first 6 months of her disease, she did not complete the sections regarding Disease Activity and Disease Damage. These two sections, particularly the Disease Damage section, are intended for patients who have experienced their disease for longer than 6 months. Note that by 4/8/14 the patient/family did feel sufficiently comfortable with and capable of commenting on the extent to which they thought any symptoms of unsuppressed active disease were present. They did not think any symptoms of unsuppressed active disease were present---i.e. if there was any active disease still going on at that time, they thought her medications were completely suppressing any symptoms of that active disease.

Susac Symptoms Serial Scores (Susac-SSS):

Note that on 12/31/13 the Total Symptoms Score was 947, the vast majority of it being due to high scores for neurologic symptoms. After her initial treatment with 4 pulses of methylprednisolone (on 1/1-1/4) her total score improved to 500. But, then she worsened (by 1/10), as reflected by her rise in score to 615. After she received more aggressive immunosuppression (1/15-1/27) her score improved to 307, stabilized in that range for a few weeks, then started to further steadily decline towards normal. By 2/26/14 her total score was down to 127, by 3/25 it was 59, by 4/29 it was 19, and by 5/15 it was down to 7.

Note that the measures of Impaired Ability (disability) and impaired Quality of Life (QOL) were also quite severely abnormal on 12/31/13---an average score of 86.7 on a scale of 0-100. By 2/26/14 that score was down to 21.3 and on 5/15/14 it was 6.7---documenting marked improvement in her physical function and QOL.

Also, note her serial QOL scores. On a scale of 0-100, with 100 being the best possible quality of life that is practical to expect, and 0 being the worst quality of life imaginable---the patient’s QOL score was 20 on 12/31/13, quickly improved to 90, and remained in the 90-91 range thereafter.

Concluding Comments:

The main reason for sharing these examples is to demonstrate the value of using these forms---both for research purposes and to facilitate and improve the care of an individual patient.

For an individual patient, the serially collected data allow the patient and their physicians to recognize how well or poorly they are doing. In this patient’s case, there was concern early in her course that she might need cyclophosphamide treatment, if she did not improve with sufficient speed and to sufficient extent. Her serial scores helped the patient and physicians to make the good therapeutic decisions they made—and to document the results of those decisions.

Continued recording of serial scores in this patient’s future will facilitate early recognition of any relapse that might occur at some time in her future (either spontaneously, or due to tapering of medication too much, too soon). If such a relapse does occur, it will be possible to compare its severity to her status during the first weeks of her illness.

So, these forms help the individual patient and physician in the management of that individual case.

But, in addition, imagine how helpful it would be if every new patient were to document the progress of their disease in the same way that the Example patient has. If all new patients were to use these same forms to document the severity and characteristics of their disease at onset and the serial changes that occur after onset of their treatment, we could learn much about the treatment needs, clinical course, and long term outcome of Susac syndrome. We could learn to recognize early indicators of who needs very aggressive immunosuppressive treatment and who might not need as much immunosuppression. We could compare patients to one another. We could document how long Susac syndrome usually remains active, how often Susac syndrome relapses, and when relapse is most likely to occur (or finally stop occurring). We would be able to compare outcomes of patients who started out the same, but were treated in different ways.

Indeed, these forms were designed to not only facilitate and improve individual patient care, but also to uniformly collect data on large numbers of patients for clinical research purposes. The patient/family responsible for these Examples has superbly demonstrated that patients/families can be empowered, enabled, encouraged, and enlisted to serve as thoughtful, competent Patient-Clinical Researchers!!

To see the actual examples, click on the following documents:

Note: It should be realized that some patients whose clinical characteristics at the time of diagnosis are similar to those of our Example patient will not experience the same reassuring course that our Example patient experienced. Some patients with almost the same characteristics at the time of diagnosis will not respond nearly as well, or as fast, as our Example patient did, even when treated in the same way, and sometimes even when treated more aggressively (e.g. with cyclophosphamide). Every patient is different—regarding how much treatment they do or do not need and how quickly they improve; and their treatment needs and clinical course are often very difficult to predict at the time of diagnosis. Some patients, who ultimately do just as well as our Example patient, have a much slower pace of improvement—i.e. it takes a longer time before their Symptoms scores become as low as those of our Example patient.

In 1975 Dr. Susac saw a young woman with a previously unreported combination of problems – a clinical triad of:

  • Encephalopathy
  • Branch retinal artery occlusions (BRAO)
  • Deafness

Shortly thereafter, Dr. John Selhorst referred to Dr. Susac a 40 year old woman with an identical set of clinical findings. In 1979 Drs. Susac, Selhorst, and John Hardiman (the neuropathologist at the Armed Forces Institute of Pathology who interpreted the brain biopsy in the Selhorst case) published a report of these two cases. The title of the report wasMicroangiopathy of the Brain and Retina.

In 1986, Dr. Susac presented a 26 year-old woman with this syndrome to the Dr. William Hoyt at a Neuro-ophthalmological Symposium held in Dr. Hoyt's honor in San Francisco. When Dr. Hoyt, one of the nation's most eminent neuro-ophthalmologists, saw the branch retinal artery occlusions, he announced the diagnosis as "Susac Syndrome."

Because the syndrome is very commonly misdiagnosed as "atypical multiple sclerosis (MS)," Dr. Robert Daroff, then Editor-in-Chief of the medical journal Neurology, asked Dr. Susac to write a brief article on the syndrome for neurologists (1994). Dr. Daroff insisted that the article be entitled "Susac Syndrome." The disease has been called "Susac Syndrome" ever since.

Since the initial report, approximately 300 patients with Susac Syndrome have been reported in the medical literature.

In 2005, at a Susac Syndrome Symposium organized by Dr. Martin Lubow at Ohio State University, Dr. Rennebohm presented to Dr. Susac a case of an adolescent with Susac Syndrome. At that symposium a concept of emphasis was that Susac Syndrome represents an "autoimmune endotheliopathy" and that the immunopathogenesis and treatment of juvenile dermatomyositis might serve as a helpful model in better understanding, treating, and studying Susac Syndrome.

By 2008 it became obvious to Drs. Susac and Rennebohm that an International Collaborative Study of Susac Syndrome would be the most effective and efficient way to increase knowledge about Susac's Syndrome. Accordingly, Drs. Susac and Rennebohm teamed up to create the content on this website to both facilitate the Susac's Syndrome International Collaborative Study and to serve as a major source of education about Susac Syndrome.

The international Neurology community, and Medicine in general, lost one of its greatest clinicians when Dr. Susac died in February, 2012 at the age of nearly 72. He was still generously and compassionately helping patients with Susac syndrome (and their physicians) until a few weeks before his death.

In July, 2012 Dr. Rennebohm moved from Calgary to the Cleveland Clinic to establish and direct a comprehensive Susac Syndrome Program, which includes an International Susac Syndrome Consultation Service and continuation of the International Collaborative Study of Susac Syndrome.

My Personal Story written by Yvonne Heerema

In January 1993 I was a busy family practitioner in Calgary, Alberta and I thought that things were pretty normal except that I was about 8 weeks pregnant and was getting over a cold that had turned into sinusitis. I had one episode of severe dizziness at the end of January. I was more tired than usual and had some trouble focusing on things, but I blamed all my symptoms on early pregnancy. My family, however, had a more significant awareness of what was occurring, and on February 10, 1993 my sister rushed to my house after a bizarre phone conversation, during which I seemed very confused, and brought me directly to my family doctor`s office.

My doctor was alarmed at my slow and abnormal thought processing and sent me straight to the hospital where I was admitted. In hospital I was found to be quite confused and had lost most of my short term memory. I became dizzy and rapidly lost my coordination when walking. Shortly after admission I developed nausea and vomiting and required an intravenous drip to correct dehydration.

There was a series of lab tests, an electroencephalogram, lumbar puncture and a MRI of my head. The tests showed general slowing of my brain waves while the MRI showed widespread abnormal spots throughout the brain. The spinal fluid had an unusually high protein content, no white blood cells and no sign of infection.

My mental functioning decreased significantly during the first week of hospitalization and I was treated with intravenous steroids for three days (pulse methyl prednisone) followed by oral high dose steroids (Prednisone 8o mg daily). An initial diagnosis of atypical multiple sclerosis was made and I was discharged to be followed up in the multiple sclerosis (MS) clinic. I was too ill to worry or think while in the hospital and just slept. In truth I had a severe sickness of the brain which is called encephalopathy and I had lost the ability for normal thought.

Read the rest of Yvonne's story

This contact information is primarily offered for questions regarding the SuS-International Collaborative Study. We suggest that:

  • Any questions about the diagnosis and treatment of an individual patient be channelled through the patient’s physician.
  • Visitors realize that the material on this website has been designed for information purposes only. It should not be used in place of medical advice, instruction and/or treatment. If you have specific questions, please consult your doctor or appropriate healthcare professional.
Robert Rennebohm, MD
  • Director of the of Susac Syndrome Program at Cleveland Clinic
  • E-mail:
  • Phone number: 216.445.6626 or 216.444.2400

Susac Syndrome Program Mailing Address

Susac Syndrome Program
Crile Bldg, Desk A111
c/o Margaret LaPlaca
Cleveland Clinic
9500 Euclid Ave.
Cleveland, OH 44195

Online Second Opinion

The MyConsult Program is an online second opinion service available to patients who would like the Susac Syndrome Program to review their medical records (and associated MRIs, fluorescein angiograms, and other studies) and offer an opinion regarding diagnosis and treatment.

Articles on Susac Syndrome