Neurosyphilis

What is neurosyphilis?

Neurosyphilis is a potentially life-threatening complication of syphilis, a sexually transmitted infection (STI). Neurosyphilis happens when the Treponema pallidum bacterium (the bacterium that causes syphilis) invades your brain and/or spinal cord. Not everyone who has syphilis develops symptoms of this complication.

Neurosyphilis and syphilis are distinct — but related — conditions. Neurosyphilis affects your central nervous system (CNS) and causes neurological symptoms. Syphilis is an STI with different signs and symptoms.

Untreated neurosyphilis can result in serious medical complications, including permanent paralysis, dementia and death. Seeking treatment as soon as syphilis or neurosyphilis symptoms appear is essential.

What are the forms of neurosyphilis?

There are five forms of neurosyphilis. Researchers break them up into two groups: early neurosyphilis and late neurosyphilis.

Early neurosyphilis

Early forms of neurosyphilis include:

• Asymptomatic neurosyphilis (ANS): This form doesn’t cause any neurological symptoms. It occurs before you develop symptoms of syphilis, too. Healthcare providers diagnose this form when a cerebrospinal fluid (CSF) analysis finds evidence of syphilis but you don’t have symptoms. If you have syphilis and don’t receive treatment, ANS generally occurs between the first few weeks to the first few years of getting the infection.
• Meningeal neurosyphilis: This form happens when the syphilis bacteria cause inflammation of your meninges — the three layers of tissue that protect your brain and spinal cord. It causes symptoms such as headache, nausea and vomiting. If you have syphilis and don’t receive treatment, this form can occur within the first few months to several years after infection.
• Meningovascular neurosyphilis: This form happens when the syphilis bacteria cause inflammation of your meninges arterial walls (endarteritis). This causes thrombosis (when blood clots block veins or arteries) and obstructs blood flow to brain tissue. It causes a variety of issues, including stroke. If you have syphilis and don’t receive treatment, this form can develop within the first few months to several years after infection.

Late neurosyphilis

Late neurosyphilis (parenchymal) forms include:

• General paresis: This form happens due to chronic inflammation of your meninges (meningoencephalitis), resulting in a breakdown of brain tissue. It causes a variety of psychological symptoms and conditions. Early symptoms include mood disturbances and personality changes. If you have syphilis and don’t receive treatment, this form can occur three to 30 years after the initial infection.
• Tabes dorsalis: This is the most severe form of neurosyphilis. It results from the breakdown of the posterior (dorsal) column and roots of your spinal cord. It causes a variety of symptoms, including movement issues, nerve pain and bladder dysfunction. If you have syphilis and don’t receive treatment, tabes dorsalis can occur anywhere from five to 50 years after infection.

Who does neurosyphilis affect?

Neurosyphilis can affect anyone who has a syphilis infection, especially if you don’t receive treatment for syphilis for months or years.

People who have unprotected sex are at high risk for the transmission of syphilis. Men who have sex with men (MSM) account for about 80% of syphilis cases in the United States.

People with HIV tend to develop symptoms of neurosyphilis sooner than people without HIV. Researchers aren’t sure why this happens, but they think it might be because people with HIV have weakened immune systems.

How common is neurosyphilis?

It’s difficult for researchers to determine how common neurosyphilis is because the reporting of cases is inconsistent. But they do know how common syphilis is — there were over 133,000 cases in the U.S. in 2020. It’s one of the most common STIs.

Asymptomatic neurosyphilis is the most common form of neurosyphilis. General paresis and tabes dorsalis are less common than the other forms due to medical advancements in the prevention, screening and treatment of syphilis.

What are the symptoms of neurosyphilis?

Neurosyphilis symptoms mainly affect your nervous system. They’re distinct from symptoms of syphilis.

The symptoms of neurosyphilis depend on its form. The earliest form — asymptomatic neurosyphilis — has no symptoms.

Meningeal neurosyphilis symptoms

Symptoms of meningeal neurosyphilis include:

• Headache.
• Nausea and vomiting.
• Neck stiffness.
• Light sensitivity (photophobia).
• Vision or hearing issues.
• Cranial nerve dysfunction.

Menigovascular neurosyphilis symptoms

Menigovascular neurosyphilis symptoms include those of the meningeal form in addition to:

• Vertigo.
• Stroke.
• Muscle weakness or loss (atrophy), especially in your legs.

General paresis symptoms

Healthcare providers divide general paresis symptoms into early and late symptoms. They can develop gradually or suddenly.

Early symptoms of general paresis include:

• Mood disturbances, such as irritability.
• Personality changes.
• Changes in sleeping habits.
• Forgetfulness.

Late symptoms of general paresis include:

• Mood swings (labile mood).
• Memory loss.
• Impaired judgment.
• Confusion.
• Delusions.
• Seizures.

It can also cause psychiatric conditions, including:

• Depression.
• Delirium.
• Mania.
• Psychosis.

Tabes dorsalis symptoms

Symptoms of tabes dorsalis include:

• Ataxia.
• Nerve pain.
• Bladder control issues.
• Abnormal sensations, such as burning or tingling (paresthesia).
• Vision changes.
• Eye issues, such as pupil abnormalities (Argyll Robertson pupils) and ocular palsies.
• Loss of coordination and reflexes.
• Neuropathic arthropathy (Charcot joint).
• Problems walking.

What are the symptoms of syphilis?

Syphilis symptoms vary depending on the stage of the infection.

In the first phase, a chancre (small, painless sore) develops on your genitals.

During the second phase of syphilis, a pink, bumpy, rough rash appears on your skin. It usually appears on the palms of your hands or soles of your feet. You may also have flu-like symptoms, such as:

• Fatigue.
• Fever.
• Sore throat.
• Muscle aches.

It’s important to seek medical care as soon as possible if you develop these symptoms. If you find out a sexual partner has tested positive for syphilis, you should get an STI test.

What causes neurosyphilis?

A bacterium called Treponema pallidum causes neurosyphilis. More specifically, the bacterium invades your central nervous system (CNS), causing neurological symptoms. This is the same bacterium that causes syphilis. The bacteria can enter your body through your anus, vagina, penis, mouth or broken skin.

Neurosyphilis can occur during any stage of syphilis.

Research suggests that in the majority of people who have syphilis, bacterium infect their CNS — often before they experience symptoms of syphilis. However, for some people, the infection of their CNS can spontaneously (randomly) go away without causing inflammation and neurological symptoms.

Syphilis, however, won’t go away without antibiotic treatment. Your risk of developing symptomatic neurosyphilis increases the longer you have an untreated syphilis infection.

Is neurosyphilis contagious?

Neurosyphilis itself isn’t contagious. It’s a complication of syphilis.

But syphilis is contagious. It spreads through sexual contact with someone who has the infection. Having unprotected vaginal, anal or oral sex increases your chances of getting syphilis.

How is neurosyphilis diagnosed?

Healthcare providers typically diagnose neurosyphilis based on your symptoms and a cerebrospinal fluid (CSF) analysis. CSF is the clear liquid that surrounds your spine and brain.

A provider will ask you about your symptoms and medical history. They’ll perform a physical exam and a neurological exam. If they suspect syphilis and neurosyphilis, they’ll order the following tests or procedures:

• Blood tests to look for evidence of the bacteria that cause syphilis.
• Lumbar puncture (spinal tap), which is a procedure in which a healthcare provider inserts a needle into your lower back to get a sample of CSF.
• Cerebrospinal fluid analysis to look for evidence of the bacteria in your CSF under a microscope.

The U.S. Centers for Disease Control and Prevention (CDC) recommends that all people with syphilis should also receive an HIV test if their status is unknown or if they previously had an HIV-negative result.

How is neurosyphilis treated?

Stopping neurosyphilis and preventing it from getting worse involves treating the syphilis infection.

Healthcare providers use antibiotics to treat syphilis and other bacterial infections. They most commonly prescribe penicillin — either by an IV in your vein or intramuscular injections (shots). Another common antibiotic for syphilis treatment is ceftriaxone.

After treatment, you’ll need several follow-up blood tests at different intervals, such as at three months and six months, to make sure the infection is gone. You’ll also need follow-up lumbar punctures for cerebrospinal fluid analysis every six months to make sure the infection isn’t present in your central nervous system.

Your healthcare provider will give you information about these follow-up tests. Don’t be afraid to ask them questions about the process.

Can neurosyphilis damage be reversed?

Antibiotic treatment stops the progression of neurosyphilis. But treatment may not be able to reverse the neurological damage that has already occurred.

People who have asymptomatic or meningeal neurosyphilis generally return to their original health if they receive proper treatment. People with meningovascular neurosyphilis, general paresis or tabes dorsalis may have an improvement in their symptoms after treatment. However, they usually don’t return to their original health.

How can I prevent neurosyphilis?

The only way to prevent neurosyphilis is to avoid getting syphilis. The only certain way to prevent syphilis is to abstain from sex.

If you’re sexually active, you can reduce your risk of getting syphilis by always using protection during sex. It’s important to use a condom or female condom properly to lower your chance of getting the infection.

It’s also important to seek medical diagnosis and treatment for syphilis as soon as you develop symptoms. Early treatment can prevent neurosyphilis from progressing to more severe forms.

What is the prognosis for neurosyphilis?

The prognosis (outlook) for neurosyphilis depends on the form you have and how quickly you’re able to receive treatment.

People who have asymptomatic or meningeal neurosyphilis and receive proper treatment usually have no lasting neurological symptoms or complications.

People with meningovascular syphilis, general paresis or tabes dorsalis often have lasting neurological symptoms or complications. But treatment can help improve symptoms and prevent neurosyphilis from getting worse. If syphilis isn’t treated, tabes dorsalis can cause death.

When should I see my healthcare provider about neurosyphilis?

If a healthcare provider diagnoses you with neurosyphilis, you must fully treat the syphilis infection. You’ll have several follow-up tests to make sure there’s no sign of the bacteria in your body. It’s important to attend these appointments.

If you have permanent neurological symptoms or conditions due to neurosyphilis, you’ll likely need to see your healthcare team regularly to receive treatment for the specific conditions.

What stage of syphilis is neurosyphilis?

Syphilis and neurosyphilis are distinct conditions. Neurosyphilis is a complication of syphilis. You can have neurosyphilis at any stage of syphilis.

A note from Cleveland Clinic

It can be embarrassing to talk about anything sex-related with a healthcare provider. But if you suspect you have syphilis, it’s important to talk to one so you can receive testing and treatment. Without early testing and treatment, you can develop long-term health problems, like neurosyphilis. Speak with your healthcare provider about regular screenings for syphilis and other STIs to reduce your risk of complications. Don’t be afraid to ask them questions. They’re available to help you without judgment.