For a normal human being, the cells in the brain fire normally, and create a perfect harmonious symphony. What happens in epilepsy is the person suffering from it goes through an uncontrollable, super fast spontaneous activity, something like hundred rock bands playing with full speed. As per the latest estimate of 2018 April, around 11.5 Mn kids are affected by Epilepsy. The severity varies significantly worldwide but little is know to patient about what causes the pediatric epilepsy and what can be done to treat it.
An Epilepsy is characterized by recurrent, spontaneous seizures, and the seizures can manifest in different ways depending on which part of the brain is involved. Generally speaking, a seizure is defined as a period of synchronous excitement of a group of brain cells happening abnormally.
When a patient’s brain goes through seizure, the cells of your brain go into a spasm of activity, usually starting with a small area or a very small group of cells and then quickly moving to a larger area of the brain. It’s like the water spreading on a surface that the seizures spread.
At times it is notices that for few seconds or minutes the person becomes completely non-responsive, this is termed as Absence seizures. On the other hand generalized seizures, can involve convulsions and falling.
Researchers from University of California, whose major area of study is in pediatric epilepsy, have found that seizures can impact a child’s life in many different ways. Some of the epilepsies can interfere with the child’s attention, impacting their activities in school. In few other cases, it directly involves brains structures which are involved in learning and memory, impacting it so severely that at times these parts do not work properly. There are many dangers lurking in there, like if a child is crossing a road and has a epilepsy attack, he will in an instant lose the ability to interact with the surroundings leading to unwanted outcomes.
If one starts penning down the number of reasons why epilepsy happens, the causes list will run into several hundreds. Different reasons leads to different types of Epilepsy. A slight lack of oxygen at the time of birth can be so critical that it could lead to refractory epilepsy.
“It is observed that few prematurely born children or those who have difficult births can have brain injuries that cause seizures during the first weeks of life,” says Paul Carney, a pediatric neurologist at the University of Florida. “The good news is that a lot of these children will outgrow their seizures in first month itself and will show no trace of epilepsy in future. However, in certain case, this could lead to a lifelong trouble with difficult to treat cases, causing acute trouble to family and the patients.
One major reason of Epilepsy in India is infection. Neurocysticercosis (NCC) and Tuberculosis being the most common, followed by viral, bacterial & fungal infections of brain. Neurocysticercosis is acquired through consumption of food contaminated with feces of a T. solium tapeworm carrier (i.e., through fecal–oral contract). Eggs of the tapeworm are shed in stool and contaminate food through poor hygiene. When these eggs are ingested, they cross the gastrointestinal tract and migrate via the vascular system to the brain, muscle, eyes, and other structures. Once in the brain, the larval cysts (cysticerci) initially generate a minimal immune response and may remain in the brain as viable cysts for years. 70%-90% cases of NCC present with seizures.
Tuberculosis can affect the brain in multiple ways; it can either involve the layers of the brain (meningitis) or brain parenchyma (encephalitis); either of which can cause seizures. Another important manifestation of Brain TB is Tuberculoma (i.e. a granuloma in brain) which usually presents with seizures. There are a lot of other ways through which TB can involve the brain, but they are beyond the scope of this discussion. On CT or MRI it is at times difficult to distinguish between NCC & TB, although MRI is more sensitive than CT in differentiating between the two.
“It is well understood in pediatric epilepsy that Seizures can be the tip of the iceberg of a serious brain disorder and earlier detection can be of tremendous difference between being able to see considerable results with treatment”
Still it must be known that there are many pediatric seizures where causes are unknown. Since there is no one cause of pediatric epilepsy, hence there is no single prognosis. In general, 50 to 75 percent of children with epilepsy will eventually have complete seizure remission. Remission is more likely if there are no underlying neurological deficits present, seizure frequency is low, and response to anti-seizure medication is good.
In India, about 32% of children who suffers from epilepsy have intellectual disabilities. With low rate of remission, the epilepsy in such children tend to exist for rest of their lives leading to other challenges. Attention deficit- hyperactivity disorder, depression, autism are common psychiatric and behavioural problems seen in children with epilepsy.
There is a field of research which is focused on understanding whether seizures themselves contribute to the cognitive deficits sometimes seen in children with epilepsy. John Swann, who studies pediatric epilepsy at the Baylor College of Medicine, believes that seizures contribute to learning and memory problems.
Swann’s laboratory induced seizures in infant mice who were otherwise neurologically normal and then tested their learning and memory skills as adults. It was found that mice that experienced recurrent seizures as infants demonstrated spatial learning and memory deficits as adults. Further studies using brain slices showed changes in the microanatomy of cells in the hippocampus, a brain region involved in learning and memory.
“We saw that these cells had fewer branches and fewer synapses, or connections between cells,” Swann says. “What this essentially means is that seizures are actually preventing the normal growth of these nerve cell branches.”
Researchers believe that they are still in earlier stage of understanding the mechanism behind this growth suppression. One field of study says, that this may be a protective mechanism that the brain is using to try to stop the seizures.
“If you decrease the number of excitatory synapses on a nerve cell branch, then the cell will be less excitable and you might have fewer seizures.”
The majority of children with epilepsy can control their seizures with anti-epileptic drugs, which act on the brain cells to make them less likely to fire.
1. The first line of treatment,is medication.
“Eighty percent of children respond well to some form of medication, and the trend over the last 10 years has been to develop medications that are better tolerated and have fewer side effects.”
2. The second line, used in case drugs don’t respond is surgery.
If seizures don’t respond to drugs, the other way is the surgery to remove a small portion of the brain where the seizures originate can be considered. Seizure remission after surgery ranges from 60 to 70 percent. While most children make remarkable recoveries after such surgeries, they sometimes suffer weakness on the opposite sides of their bodies from the surgery site.
3. The third form is Vagus Nerve stimulation.
Another option for medication-resistant epilepsy is vagus nerve stimulation. The vagus nerve controls body functions that are not under voluntary control, such as heart rate. In vagus nerve stimulation, a device like a pacemaker is implanted just under the left collarbone with a wire that delivers regular, mild electrical current to the vagus nerve and stimulates the brain. It is thought that this stimulation helps calm down the irregular brain activity that leads to seizures. This treatment has been shown to decrease seizure frequency by half in at least one-quarter of children.
Finally, a special diet can be considered for children who do not respond to anti-epileptic medication and who are not good candidates for surgery. The ketogenic diet is a high-fat, low-carbohydrate diet that mimics a fasting state and forces the body to use fat rather than carbohydrates as an energy source. While scientists don’t understand how it works, the ketogenic diet has been used for nearly 100 years to control epileptic seizures.
There is still a mystery surrounding the fact of what makes some pediatric epilepsies resistant to medication.
However, new animal models and advances in neuroimaging and genetics offer new hope for treatment. Improvements in magnetic resonance imaging (MRI) have helped doctors detect structural brain malformations in children with drug-resistant epilepsy, making successful surgical intervention more likely.
In addition, scientists have identified many genes that contribute to different pediatric epilepsy syndromes, and they believe that medications tailored for specific genetic mutations are on the horizon.
There are many pediatric epilepsies with which a gene hasn’t been associated yet, but it’s just a matter of time. There’s reason to be hopeful. Things are changing rapidly. We’re beginning to understand in some detail what is causing epilepsy and how it’s generated, and with that we are pursuing new ways to treat it.
While experiencing uncontrollable seizures can be catastrophic for the developing brain, both human and animal research is moving at a rapid rate to help children live seizure-free lives.
The writer is Dr. Navdeep Kumar, MD(Medicine) DNB (Neurology) who practices at Indo Gulf Hospital Noida, India and is rated as No. 1 Neurologist in Delhi NCR.