Medical mystery: Dravet epilepsy syndrome Friday, 03 February 2012 03:35

The medical mystery began when a couple’s third child, 6-month-old Michaela, had just suffered a serious seizure and was sent to a nearby hospital. At the hospital, doctors reassured her that Michaela had suffered a febrile seizure, a frightening and usually harmless event they said was unlikely to recur. As a precaution, the baby was admitted for observation. Just hours later, doctors had trouble controlling a second, more severe seizure.

That night in July 1997 marked the beginning of a 101 / 2-year ordeal, as more than a dozen specialists in four states tried without success to find an underlying cause for Michaela’s frequent, in¬trac¬table seizures — and a treatment that would control them before they caused irreparable brain damage or death.

It was quickly evident that Michaela’s seizures were not just febrile: They occurred when she had no fever, and doctors suspected she had epilepsy. “She would be in her bouncy seat and both arms would just shoot straight up in the air,” Cossolotto recalled. “I knew nothing about epilepsy.”

She soon learned. At times Michaela’s seizures were so severe that doctors had to place her in a drug-induced coma to save her life. Despite test after test, no doctor could say what kind of epilepsy she had, and no cocktail of medications proved effective in controlling the seizures. Nor did doctors know the reasons for problems that emerged as she aged: delayed speech, mild mental retardation and serious growth deficiency.

The seizures unabated, Cossolotto called the Mayo Clinic in Rochester, Minn. A pediatric neurologist there began treating Michaela with various antiseizure medications while continuing the search for an underlying cause. At one point the little girl was seizure-free for nearly a year, but the convulsions returned, worse than ever.

In September 2007, Cossolotto took Michaela, then 10, to see a pediatric geneticist who had been featured on a TV show about baffling medical cases. A suggested referral to Elaine Wirrell, the hospital’s new pediatric epileptologist, a neurologist who specializes in treating children with epilepsy was made. “I had never heard of an epileptologist,” Cossolotto said.

In November 2007, Michaela saw Wirrell, the latest in a seemingly endless parade of doctors. The appointment seemed like so many others. After listening to Michaela’s history and reviewing her records, Wirrell told Cossolotto that she suspected a rare disorder and wanted to order a test.

Three weeks later, Wirrell called Cossolotto with the definitive answer that had eluded her for so long. The blood test for the SCN1A gene revealed that Michaela had Dravet syndrome, also known as severe myoclonic epilepsy of infancy, a rare and serious form of the seizure disorder named after the French doctor who described it in 1978.

Dravet is usually caused by a spontaneous — not inherited — genetic mutation present at birth that affects the functioning of brain cells, according to the National Institute of Neurological Disorders and Stroke. Its hallmark is severe seizures during the first year of life that are difficult to control. Many children with Dravet, which occurs in one in every 20,000 to 40,000 births, also exhibit poor language skills, behavioral problems and cognitive deficits. There is no cure for Dravet, but some medications are effective in controlling seizures. Among them are clobazam combined with stiripentol, a French drug that has not been approved by the Food and Drug Administration but can be legally imported because it treats a rare illness.

As a result of the diagnosis and proper medication, Michaela’s life has dramatically improved. Although she still grapples with cognitive and behavioural problems, her seizures have dwindled to only a handful annually. Now 15, she is a freshman in high school with friends, a Facebook page and other trappings of adolescence.

WP-Bloomberg

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