Online Health Chat with Dr. Neil Friedman
May 26, 2010
Cleveland_Clinic_Host: Stroke is one of the top 10 causes of death in children, and the majority of pediatric stroke survivors will have lingering, persistent neurological and/or cognitive impairment. Epilepsy may develop in a significant number of stroke survivors. However, children tend to recover from stroke better than adults, due mostly to the plasticity of their brains (ability of brain networks to reorganize and recover following injury) and the fact that their brains are still developing.
The risk of stroke is highest during the first year of life, but stroke may occur any time throughout childhood or adolescence. Perinatal stroke – during the late stages of pregnancy and through the early newborn period – occurs in about 1 in every 3,000 live births. Boys and African-American children are at higher risk than other population groups for stroke.
U.S.News & World Report ranks Cleveland Clinic Pediatric Neurology and Neurosurgery program among the top four in the nation, and we are also ranked best in Ohio. Our pediatric neurology team works closely with pediatricians and pediatric specialists at Cleveland Clinic Children’s Hospital, offering advanced medical care and rehabilitation services for acute illnesses and injuries as well as for chronic and disabling conditions.
Neil Friedman, MBChB, obtained his medical degree from the University of Cape Town, South Africa in 1987. He spent the next 18 months working in a rural hospital in South Africa gaining clinical experience before working in London, England, for the next three years in various pediatric subspecialty fields. This included 10 months of research in pediatric neuromuscular disorders under Professor Victor Dubowitz at the Royal Postgraduate Medical School, London, United Kingdom.
His specialty training included a Pediatrics residency at the University of Arizona (1995) with subsequent completion of a Neurology fellowship with special qualifications in Child Neurology through Children’s Hospital, Boston (1998).
Since 1998, Dr Friedman served as a staff physician in Pediatric Neurology at the Cleveland Clinic. He is board-certified in both Pediatrics and Neurology. He is the director of the Pediatric Neurology Training Fellowship since 2003.
Dr. Neil Friedman’s specialty interests include pediatric stroke, the neurological complications of congenital heart disease and cardiomyopathy, pediatric neuromuscular disease and neonatal neurology. He has been instrumental in establishing an Ohio Pediatric Stroke Registry and is a member of the International Pediatric Stroke Study consortium. He has also established a protocol for the neuromuscular and neurometabolic evaluation of children with idiopathic cardiomyopathy and has established a multidisciplinary pediatric neuromuscular clinic for the comprehensive evaluation, diagnosis and treatment of children with neuromuscular disease.
To make an appointment with Dr. Neil Friedman or any of the other specialists in our Center for Pediatric Neurology& Neurosurgery at Cleveland Clinic, please call 216.636.5860 or call toll-free at 866.588.2264. You can also visit us online at clevelandclinic.org/pediatricneurology.
Cleveland_Clinic_Host: Welcome to our Online Health Chat with Dr. Neil Friedman. We are thrilled to have him here today for this chat. Let’s begin with the questions.
Pediatric Stroke: General Information
Wilma: Why do we see more strokes in boys?
Speaker_-__Dr__Neil_Friedman: Even allowing for trauma, the incidence of stroke in boys remains higher than girls for childhood stroke. While trauma may be explained by boys being generally more boisterous and active, it is unclear why this sex ratio difference is true, even when trauma is excluded. A recent paper from Germany suggested that there may be a correlation with testosterone levels and pediatric stroke and this may potentially explain, in part, the sexual bias. In truth, we still do not fully understand this discrepancy.
Pediatric Stroke: Risk Factors
johnstorm: What are the risk factors for pediatric stroke?
Speaker_-__Dr__Neil_Friedman: There are multiple risk factors for pediatric stroke. This is in contra-distinction to adult stroke, where degenerative disease, hypertension and atherosclerosis are the major risk factors. In children, about 25-30% of arterial ischemic stroke are caused by underlying cardiac disease, including congenital heart disease. We know also, from recent studies that about 80% of children show evidence of cerebral blood vessel abnormalities on vascular imaging. This includes trauma (dissection or tear of the artery), genetic vascular diseases (e.g. Moya Moya), post-infectious causes (e.g. post-chicken pox), hematologic disorders (e.g. sickle-cell disease) and disorders of clotting.
Pediatric Stroke: Causes
Wilma: My son was born with several clots in his body, but he does not have any blood disorders or heart problems and has been healthy since. Can the stress of simply being born cause clots and stroke in infants?
Speaker_-__Dr__Neil_Friedman: I presume that reference to 'any blood disorders' means that clotting disorders or hypercoagulable disorders were excluded. We know that pregnancy and the period around delivery results in a lot of changes to the blood coagulation system, especially in the mother. Studies have shown that transient coagulation abnormalities in the newborn have been seen in up to 50-70% of cases. However, these clotting disorders are transient and are likely risk factors for clotting around the time of birth, but do not persist beyond birth. Conversely, if underlying clotting disorders and cardiac disorders can be excluded in a neurologically normal newborn with stroke, the risk for future stroke in that child is less than 3%.
lindsay: Is it true in utero strokes occur when either one- mom is dehydrated, or mom's blood pressure drops really low.
Speaker_-__Dr__Neil_Friedman: In general, when a person's blood pressure drops or if one is severely dehydrated, there is a general decrease in blood flow to the entire brain. This will usually result in a more global type of brain injury (global hypoxia) or what is known as a watershed infarct/stroke rather than a focal injury to the brain, which we traditionally regard as a stroke. The reason for the in utero strokes in not well known, in many instances.
lindsay: My son had hydrocephalus up until about 3 weeks until birth, but then at 11 months we found out he had an in-utero stroke. Could the hydrocephalus have caused this?
Speaker_-__Dr__Neil_Friedman: If I understand the question correctly, it would appear that during the pregnancy they saw enlargement of the ventricles (fluid filled cavities in the center of the brain). Enlargement of the ventricles may be due to increased pressure (hydrocephalus), but can also be enlarged secondary to a loss of brain tissue (no pressure concerns). If this is unilateral (i.e. one-sided) then it is possible there had been a stroke in utero, with damage or loss of tissue on that side and compensatory enlargement of that ventricle. If the compensatory enlargement is bilateral (both sides), then it would imply more diffuse brain injury than a focal stroke. Finally, hydrocephalus itself, because of the increased pressure, can potentially obstruct blood flow to the brain with secondary stroke. I hope this answers the question.
colin919: My daughter also had a prenatal stroke, but was not premature, no problems during pregnancy, etc. Is there any way to find out the cause of this?
Speaker_-__Dr__Neil_Friedman: Unfortunately, despite recent advances in our knowledge of prenatal and childhood stroke, the majority of prenatal strokes go undiagnosed. As in a previous response, it is important to exclude underlying cardiac causes or clotting disorders in these instances. If the child is otherwise neurologically normal, and no suggestion of any genetic or metabolic type problem, then the risk for recurrent stroke in a child with in utero stroke is thought to be very low (less than 3%).
Pediatric Stroke: Complications
andreas: What are the chances of a child who suffered a stroke at birth and suffers from relatively mild partial complex seizures to become seizure free? Do these seizures typically worsen in frequency and intensity as a child grows?
Speaker_-__Dr__Neil_Friedman: Great question. In general, we know that approximately 30-50% of children that suffer stroke during childhood will develop epilepsy (recurrent seizures). We refer to this as symptomatic epilepsy, given the underlying brain injury. There is less information regarding seizure freedom in these children. Generally, with respect to epilepsy, we try and treat children until they are two-year seizure free, before attempting to take them off medication. This is successful in about 70% of cases. Whether children with underlying stroke have a higher risk for relapse is not yet definitively known. As far as frequency and intensity of seizures, this is highly variable and not necessarily predictable, at the onset.
JacksMom: Is it possible that a childhood stroke survivor (stroke at 2 days old) may never develop seizures?
Speaker_-__Dr__Neil_Friedman: Yes. As previously mentioned in an earlier response, we believe the overall risk for the development of epilepsy (recurrent seizures) is about 30-50%, depending on the area of brain involved. Seizures are frequently the presenting feature in newborn strokes (over 90% of cases). However, the risk for subsequent epilepsy is probably the same (30-50%), depending on the series that have been published.
minmom68: My soon to be 9 year old son had a stroke around birth. He has a problem with body temperature regulation, especially when in the shower or pool or ocean. The water has to be very warm (85+), otherwise he complains it is too cold and he forms goosebumps and his teeth chatter. Other parents of an online support group for child stroke survivors have mentioned this about their children also. Could this be related to the stroke and the way the brain is affected or could it be another issue? My son is Factor V Leiden Deficient and is also on medication for complex partial seizures - if this information is pertinent for the answer.
Speaker_-__Dr__Neil_Friedman: This is an interesting observation that I have not specifically heard of before. Certainly, in children with extensive brain injury or damage from any reason can get hypothalamic dysfunction, i.e. the hormonal regulation control center for temperature can be affected. In more 'typical' strokes seen in children, the degree of brain injury is usually not severe enough to result in hypothalamic dysfunction. I suspect this may potentially be an unrelated issue to your son's stroke.
jacksdad: Is it true that motor recovery may have better outcomes when the area of stroke is located in the cortex vs. inner capsule?
Speaker_-__Dr__Neil_Friedman: This can be true and depends, to a large degree, on the extent of the stroke. If one thinks of the cortex as a parachute, the strings from the parachute then come together in a much smaller, narrower area. So a smaller area of injury, in this narrower area (i.e. the internal capsule) can result in as much, or more, damage as the same size stroke over the surface of the brain. The internal capsule can be considered, therefore, 'prime real estate’ as far as injury to motor fibers is concerned.
jacksdad: Do strokes resulting in hemiparesis always have decreased sensory reception associated in the affected limb(s)?
Speaker_-__Dr__Neil_Friedman: Not always. While we do know that sensory impairment following stroke occurs, many recent studies in children have focused more on the motor deficit than the sensory deficit. Sensory involvement depends to a large extent on the location of the stroke in the same way that speech is not always affected in a child with a stroke (also depends on the area of involvement). It is certainly in the area that requires more attention and focus, but it is not uncommon to see impaired sensation in hemiplegic stroke.
Pediatric Stroke: Diagnosis & Treatment
bkellogg1: Dr. Friedman thanks for your time. I am curious what (if any) vitamins, minerals, etc. are out there that may help support healing, growth, and recovery for a child's brain after suffering a stroke? Also, is there any long term impact of anti-convulsants on kids over time? Thank you.
Speaker_-__Dr__Neil_Friedman: While certainly having good nutritional status helps and promotes growth in general, there are no specific vitamins or diets that have unequivocally been shown to improve stroke outcome in children. In certain situations, such as MTHFR gene deficiency, supplementation with vitamin B and Folate helps to reverse the effect of the enzyme deficiency and reduce homocystine levels, thereby reducing stroke risk. Some people believe coenzyme Q10, which is a transporter for electrons in our mitochondria, may help energy production and have possible benefits in many medical conditions, including stroke.
As far as long-term impact of anti-convulsants on children, in general there does not appear to be any significant long-term impact with respect to the stroke or neurological outcome. To qualify this however, some children do suffer adverse effects from these medications. This often depends on the specific medication as to the specific side-effect. Rarely, as with any medication, bad reactions and allergies may occur.
cmm: In an emergent stroke, how are pediatric patients treated, and is it different from adults?
Speaker_-__Dr__Neil_Friedman: This is a great question and gets at the heart of one of the major problems we still face with pediatric stroke, namely the recognition that stroke occurs in children. We know that the earlier one can diagnose stroke and intervene, the better the outcome, as damage continues to occur even hours after the initial stroke. The management, as in adults, is aimed at preserving viable brain tissue. Supportive measures to maintain blood flow to the brain are important. This includes maintenance of blood pressure, as well as other supportive interventions such as temperature control (possibly reducing body temperature/hypothermia), maintaining normal blood sugars and efforts to prevent recurrent stroke.
While clot dissolving drugs, such as TPA, have not been approved in children, anticoagulation with blood thinners (in the appropriate setting) may be indicated. Equally important is determining the cause of the stroke, as specific therapy may be indicated. Children with stroke should be evaluated and treated at centers with the expertise and skills necessary in pediatric stroke, rather than in adult centers.
mmirabito: What advice can you give parents considering constraint induced movement therapy for children with impacted limbs?
Speaker_-__Dr__Neil_Friedman: Constraint therapy is an old therapy that is again finding favor in the pediatric rehabilitation world. It involves restraining the normal arm, thereby encouraging the use of the weak or paretic arm or hand in the hopes of improving function. This is equivalent to patching a good eye when a child has strabismus or squint. In many children, constraint therapy can be very effective. One does need to monitor for frustration and make sure that this is not counterproductive to the therapy.
cmm: In the event of an ischemic stroke, does use of anticoagulant therapy increase the risk of hemorrhage; and if so, do you use it to prevent the extension of the ischemia?
Speaker_-__Dr__Neil_Friedman: This is a complicated question to answer in a few lines. In general, if the ischemic stroke is 'bland,' (i.e. scans show no evidence of blood) the risk of anticoagulation is considered low. Even in the presence of a small amount of blood with an ischemic stroke, anticoagulation can be safely used, if monitored closely and in the correct setting (pediatric ICU). There is a risk, in these instances, for potential extension of the bleeding, and therefore worsening of the stroke or increased intracranial pressure. The reason for using anticoagulation is both to try and stop clot progression (if that is the cause of the stroke) or prevent secondary stroke while the cause for the stroke is being evaluated. Again, I would stress that this only be done in an appropriate setting and preferably by a pediatric stroke specialist in conjunction with their other pediatric specialist colleagues.
mxz111: My daughter had a stroke during birth. She has 2 copies of MTHFR gene. Is she more likely to get another stroke?
Speaker_-__Dr__Neil_Friedman: Homozygous mutations in the MTHFR gene (i.e. both copies of the gene affected) does predispose a person to increased clotting risk. This is a risk factor, such as would be seen with diabetes, hypertension or elevated cholesterol in an adult patient. It is often not the sole cause of the stroke, but does increase a child's likelihood for stroke in the 'correct' setting (e.g. dehydration). The mechanism of stroke with MTHFR gene mutation is thought to be elevated blood homocystine levels. Fortunately, supplementation of vitamin B and Folic acid helps to reverse the effects of the enzyme deficiency, thereby normalizing the homocystine level and therefore reducing the stroke risk. As an aside, this is a genetic disorder and it is possible that either parent may also be homozygous for this mutation and therefore at risk for stroke, themselves. I would therefore recommend you and her father be tested, if this has not already been done.
Cleveland_Clinic_Host: I'm sorry to say that our time with Dr. Neil Friedman is now over. Thank you again Dr. Friedman for taking the time to answer our questions about Pediatric Stroke.
Speaker_-__Dr__Neil_Friedman: Thank you for joining me today. I am sorry if I was unable to answer all of your questions, but I did try to at least answer one question from everybody, on a wide variety of topics. Time will not allow me to answer them all, there were so many questions! I will try to answer some additional questions that will be posted in the transcripts, so please check back at clevelandclinic.org/webchat in a week's time. For more information about pediatric stroke, please feel free to visit us at clevelandclinic.org/pediatricneurology.
At the request of many of my families, we have set up a pediatric stroke support group and details of our first meeting here in Cleveland on 8/21/10 will soon be posted on the above website. I hope you can join us for this, and I will be available to answer additional questions at that time.
- To make an appointment with any of the other specialists in our Center for Pediatric Neurology& Neurosurgery at Cleveland Clinic, please call 216.636.5860 or call toll-free at 866.588.2264. You can also visit us online at clevelandclinic.org/pediatricneurology.
- A remote second opinion may also be requested from Cleveland Clinic through the secure eCleveland Clinic MyConsult website. To request a remote second opinion, visit eclevelandclinic.org/myConsult.