By Dr Vipul Gupta
Pediatric strokes even though rare, is one of the leading causes of significant morbidity and mortality. In comparison to stroke occurring in adults, children present differently with unique risk factors that often optimizes the outcomes. As the risk factors for pediatric stroke vary from that in adults, the cases are often diagnosed at later stages, or remain misdiagnosed.
According to the data reported in various International journals, mortality rate of children suffering from stroke under the age of 15 years is around 25% and the remaining will have a recurrence or will have persistent neurological disorders, difficulty in learning or seizures. Unlike adults where the risk factors are predominated by diabetes, hypertension and atherosclerosis, pediatric risk factors are more diverse and larger in number.
However the instances of pediatric stroke are under reported and may be more than we realize. This is attributed to the fact that the symptoms mimic other diseases that lead to misdiagnosis and hence delay in its treatment. With recent advancements in the field of neurointervention, the survival rates of pediatric stroke (also suffering from congenital heart ailments, sickle cell disease or other blood disorders) has doubled due to improved intervention and awareness.
What is pediatric stroke?
Stroke is caused by the occlusion or rupture of arteries and veins in the brain and can be ischemic or hemorrhagic or both. Ischemic strokes are more commonly caused due to arterial blockage, but can also happen with venous blockage. When the blockage leads to rupturing of the blood vessels causing bleeding it is termed as hemorrhagic stroke. Ischemic stroke in adults accounts for 85% of all strokes whereas only 50% are attributed in the case of pediatric stroke.
Children are also vulnerable to a mini stroke (Transient Ischemic attacks – TIA) when the blood supply to the brain is interrupted for a very short time. Usually the symptoms subside immediately after TIA, but the chances for a stroke to occur within the next 24 hours doubles.
What are the symptoms?
As stroke can happen at any age, from infancy to adulthood, the age determines the appropriate treatment option for the neurointerventionist. It is thus often misdiagnosed due to the fact that the effects of stroke or its symptoms are not noticeable.
Strokes are first detected when the problems arise with their learning and development. Most noticeably there may be problems with movements in only one side of the body. Seizures are the most common symptom in infants upto 28 days old and in children upto 18 years may experience weakness or paralysis on one side of the body, facial drooping, speech problems and headaches. These symptoms are most commonly associated with ischemic strokes. Symptoms for hemorrhagic strokes include vomiting, seizures and occasional headaches.
The effect of stroke depends on the area of occurrence of stroke in the brain and the amount of damaged caused. People having larger strokes can be permanently paralyzed on one side of their body or lose their ability to speak. But some having small strokes may only have temporary problems like weakness of an arm or leg. With timely intervention most of the cases are recoverable completely.
Who is at more risk?
The risk factors and reasons for pediatric stroke are distinct and varied including malformations in the blood vessels and other congenital abnormalities.
Ischemic stroke is the leading cause pediatric stroke and the risk factors include –
1. Congenital heart ailments - Heart disorders cause up to 25 per cent of ischemic strokes in children. They can be a result of congenital heart disease, an abnormality present since birth or acquired heart disease. Stroke is not usually the first sign of heart disease. Often heart disease has been diagnosed before the child has a stroke.
2. Congenital Blood Disorders – also known as prothrombotic disorders, the condition causes the blood to thicken and clot faster. Sickle cell Disease (SCD) is another inherited condition that affects the development of RBC and changes its shape from round to sickle. Though rare, it can also cause bleeding in the brain blood vessels. Other conditions include leukemia, Anemia, and autoimmune disorders.
3. Arterial Malformation – stroke can occur due to irregular formation of arteries in the brain. Being congenital, children born with this condition often go undetected until the symptoms of stroke are persistent. Such kids need regular monitoring for recurrent strokes.
Hemorrhagic strokes attributes to 50% of the cases of pediatric stroke and the main reason is Arterio-Venous Malformation (AVM). It is a rare malformation of the arteries and veins where the high pressure blood pumped from the heart to the brain directly move to the veins that passes blood at relatively low pressure. This change in pressure causes rupturing of the vessels thereby causing bleeding.
How is it treated?
The treatment for hemorrhagic stroke focuses on stabilizing the child by controlling the blood pressure, body temperature and prevents shortness of breath before treating the hemorrhage. The surgical options include microsurgery to clip the aneurysm or remove the abnormal vessels.
The treatment for ischemic stroke works on to reduce the damage to the brain and prevent another stroke. Doctors prescribe blood thinner and also monitor reflexes, eye movements, speech skills, swallowing and other body functions. Also how the child is processing to and reacting to light, pictures, sound and touch.
Dr Vipul Gupta is the Director, Neurointervention, Agrim Institute for Neuro Sciences, Artemis Hospital