Dravet Syndrome and the Challenges of Pediatric Epilepsy

An interview with Dr. John J. Millichap


John J. Millichap, MD FAAP, is a pediatric epileptologist in the Comprehensive Epilepsy Center at Ann & Robert H. Lurie Children’s Hospital of Chicago and an Assistant Professor of Pediatrics and Neurology at Northwestern University Feinberg School of Medicine. Dr. Millichap trained in Pediatrics at the Brody School of Medicine at East Carolina University prior to Child Neurology and Clinical Neurophysiology/Pediatric Epilepsy fellowships at Northwestern University.

Dr. Millichap has over 30 peer-reviewed medical publications and serves as the Deputy Associate Editor of the Resident and Fellow Section of the journal Neurology and the Editor of Pediatric Neurology Briefs. As a member of the academic faculty, he is involved in the education of trainees and grant funded clinical research concerning epileptic encephalopathies.

Science in Society spoke with Dr. Millichap about Dravet Syndrome, a severe form of pediatric epilepsy, and his work as an epileptologist.

What is Dravet Syndrome?

Dravet syndrome is a severe form of epilepsy that begins in infancy. The syndrome was first described in 1982 by a French doctor named Charlotte Dravet and was initially named "severe myoclonic epilepsy of infancy." The name was later changed to honor the doctor who discovered it. Dravet syndrome is a rare form of epilepsy in the general population, but can represent roughly 5 percent of patients with their first seizure before the age of 1 year old.

What are the signs and symptoms of Dravet Syndrome?

Dravet syndrome is characterized by an onset of seizures in the first year of life, followed by a variable course that includes different seizure types, developmental regression, and uncontrolled seizures. The initial seizures are often distinct and consist of jerking of one side of the body for prolonged period of time. Seizures are often triggered by fever, infectious illness, change in body temperature, or flashing lights. Development is normal when the seizures begin, but parents may recognize loss of developmental milestones such as walking and talking in the second year of life.

What causes Dravet Syndrome?

Variations in the gene named SCN1A are found in a high proportion of Dravet syndrome patients. This gene codes for what we call a voltage-gated sodium channel. Sometimes seizures are caused by problems in part of the body called "ion channels." Ion channels are tiny parts of the brain cell lining that control the amount of "ions" (these are salts like calcium, chloride, potassium, and sodium) inside and outside the brain cells. Too much or too little of a particular ion inside or outside of the brain cell can make the cell misfire and cause seizures. 

Can Dravet be inherited?

Almost all cases of Dravet syndrome are not inherited and are caused by new pathogenic variants in the SCN1A gene. There are complex situations where the variation may be passed from one parent to the child, but the parent does not have seizures or may have seizures that are better controlled with medication without the severe problems with development.

How is Dravet diagnosed?

Dravet syndrome is a clinical diagnosis, meaning that the diagnosis is based on the age of onset of seizures, seizure types, and progression of symptoms. Other features such as the EEG patterns and brain imaging are also considered. The genetic testing can confirm the condition, but is not required for the diagnosis.

How is Dravet treated or managed?

After diagnosis, there are specific seizure medications that are known to be more effective than others. We are hopeful that early and effective treatment may reduce the seizure burden and improve long-term developmental outcome. In addition to controlling seizures, parents are counseled regarding prognosis and measures to maximize developmental progress with therapy and testing. The mortality rate in Dravet syndrome is higher than other causes of seizures so specialized care is important to minimize this risk.

Can a person die from a seizure?

The majority of seizures are brief and will end on their own without intervention or immediate harm to the person. Since seizures occur unexpectedly, they can create dangerous situations that increase the risk of death from drowning or other accidents. Very long seizures, referred to as "status epilepticus,” can be life-threatening if none of the medications or other treatments are effective. We also counsel patients and their families about “Sudden Unexpected Death in Epilepsy” (SUDEP), which refers to a unexpected passing of a patient with epilepsy and no other cause of death determined. We don't know why this happens, but research is underway to study this and hopefully prevent it. SUDEP occurs more frequently in people with epilepsy whose seizures are poorly controlled.

How do seizures affect quality of life?

Seizures interrupt life, and a single seizure can continue to affect the daily life of an individual long after it has stopped. A child with seizures may miss school and learning opportunities, while an adult may miss work or be unable to drive. A person with uncontrolled seizures may have to limit certain activities due to a risk of injury. Except for those severe situations, persons with controlled epilepsy should be encouraged to "live life" and engage in any activity they wish as long as they keep the potential risks in mind and follow common sense.

Can epilepsy be cured?

The International League Against Epilepsy (ILAE) revised the definition of epilepsy in 2014. Important changes included the use of the word "disease" rather than "disorder." Most persons diagnosed with epilepsy cannot be cured, however, the seizures may be completely controlled with treatment. The new definition does include one specific situation where the “epilepsy is considered to be resolved for individuals who had an age–dependent epilepsy syndrome but are now passed the applicable age or those who will have remained seizure-free for the last 10 years, with no seizure medicines for at least 5 years." This change is important for the practical application of the term epilepsy in the restrictions associated with the diagnosis.

What are common triggers for seizures?

Different situations in the environment or in the body may "push" a person with epilepsy over the threshold and cause him to have a seizure. Each person will have individual triggers, but some are more common than others. Patients with epilepsy are counseled to avoid situations that may cause stress on the body such as sleep deprivation, fever, illness, alcohol use, and poor diet. Some triggers are unavoidable such as menstrual cycle for women or taking other necessary medications.

How can someone help a person having a seizure? Is there a way to stop a seizure? 

Most seizures will stop on their own within a few minutes. The most important thing is to stay calm yourself so you can help the person. Check your watch so you can keep track of the duration of the seizure. If the seizure lasts longer than the person's usual events, or if you are not sure, then call for help. Prevent injury by helping the person to the ground or moving objects out of the way. Parents of children with epilepsy are often prescribed a rescue medication that can be given rectally and help shorten the seizure.

Can a person swallow their tongue during a seizure? 

No, and it is very important not to put anything in a person's mouth during a seizure since the jaw muscles may tighten and cause a person to bite down.

Does age affect severity of seizures (does the disease progress with age or regress)?

Seizures can be severe at any age and the progression of the disease will depend on the specific cause. There are many causes of epilepsy and these are distributed differently in different age groups. Looking at all types of epilepsy, the most severe forms that are associated with developmental delay or regression have seizure onset under 2 years of age.

Why isn’t there a cure for epilepsy? What about the disease makes it hard to treat? 

We work hard to determine the exact cause of the epilepsy to provide the patient with the most effective and targeted treatments available. For example, if there is a structural abnormality in the brain, such as a tumor, causing seizures then surgical removal of the tumor may provide a "cure," meaning that the person does not have epilepsy and does not require daily seizure medications. Knowledge of other causes of epilepsy, such as variations in the SCN1A gene, allows doctors to choose specific medications and anticipate changes in the patient's condition with time.

What kind of training do you need to become an epileptologist like yourself?

Becoming any type of physician is a serious commitment that requires many years of education and subsequent specialty training. This effort is worthwhile as it leads to a lifelong career of helping others and working to solve complicated problems.

An interest in science during high school is useful, since there are basic requirements for the premedical college curriculum including chemistry, physics, biology, and mathematics. Each medical school is different, but I have heard that many successful applicants study a non–science major such as English or history since communication and writing is such an important part of what physicians do.

Following the 4 years of medical school, physicians may choose from many specialties or general care for children, adults, or both. The training to become a pediatric epileptologist is 6 years minimum after becoming a doctor. There are 2-3 years of general pediatric training, followed by 3 years of specialty training in pediatric neurology focused on all neurologic diseases including headaches, muscle diseases, nerve diseases, strokes, and epilepsy. Pediatric epilepsy is a subspecialty of neurology with special qualifications in the interpretation of the electroencephalogram (EEG), the test that records brain waves and can help to diagnose seizures and other types of brain dysfunction.

Once the doctor completes necessary training, there are different opportunities for practice in a private clinic or in a larger group at a university hospital. Usually doctors at University Hospital's will also be involved in medical research to help understand the causes of disease and develop new treatments.



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