Men in Black” was flickering on the screen, and Laura Cossolotto and her husband were enjoying a rare night at the movies in their home town of Centerville, Iowa, when her brother-in-law rushed into the darkened theater.

The couple’s third child, 6-month-old Michaela, had just suffered a serious seizure and was at a nearby hospital. As Cossolotto raced to be with the baby, she immediately remembered that Michaela had been running a fever after receiving a vaccine against diphtheria, pertussis and tetanus (DPT) three days earlier.

“I thought the shot must have something to do with it,” Cossolotto recalled. “I had three kids, and nothing like this had ever happened, so what else could it have been?”

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. Hours later, after doctors had trouble controlling a second, more severe seizure, the infant was whisked by helicopter to a larger hospital in Des Moines, 100 miles north.

That night in July 1997 marked the beginning of a 10 1/2-year ordeal, as more than a dozen specialists in four states tried without success to find an underlying cause for Michaela’s frequent, intractable seizures — and a treatment that would control them before they caused irreparable brain damage or death.

For years Cossolotto held the DPT shot responsible for Michaela’s problems, joining legions of parents who have blamed various ingredients in pediatric vaccines for triggering serious medical and developmental ills, most notably autism. Since the early 1980s these allegations, based on discredited theories and more recently on an influential British study that last year was deemed an “elaborate fraud,” have flourished, largely because of their enduring popularity on the Internet. As a consequence, fearful parents have refused to immunize their children, resulting in outbreaks of vaccine-preventable diseases, including measles and whooping cough.

Cossolotto, who spent hours online desperately seeking answers, found the vaccine hypothesis persuasive, particularly after doctors failed to offer another explanation. The belated discovery of what was wrong with her daughter would upend Cossolotto’s long-held views and lead to major improvements in Michaela’s life.

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. Eight times before she was 3, she was helicoptered to Des Moines or Iowa City for emergency treatment. “I remember sitting by her bed in the ICU wondering: Would she wake up? And if she did, would she be a vegetable?” Cossolotto recalled.

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.

Specialists ruled out fragile X syndrome, a chromosomal disorder that causes mental retardation, gastrointestinal malabsorption, cystic fibrosis and numerous rare metabolic problems as well as heart defects and brain malformations.

Between the ages of 3 and 5, Michaela did not gain an ounce; she entered kindergarten at age 5 weighing 33 pounds, roughly the average weight of a 2 1/2-year-old girl. At a growth clinic where she was evaluated for failure to thrive, doctors told Cossolotto “the problem was that I allowed her to graze during the day and that I was a bad parent,” she recalled.

Around the age of 4, Michaela began regressing, displaying what seemed to be classic signs of autism: She would rock for hours, avoid eye contact and seem to retreat into her own world. By this time Cossolotto was spending hours a day scouring the Internet. She quickly turned up what seemed to be a promising explanation: pediatric vaccines.

Michaela’s doctors were skeptical, but Cossolotto became increasingly convinced she had found a possible answer. She began taking her daughter to see a specialist in environmental medicine in St. Louis, five hours away. He embraced the vaccine theory and ran his own series of tests, diagnosing a mold allergy. At Cossolotto’s request, he signed a waiver allowing Michaela to attend kindergarten without receiving the required immunizations. “I wasn’t taking any chances,” her mother recalled.

But after several months autism faded from the picture: Remedial help Michaela received in school caused the autistic behaviors to recede. Cossolotto’s belief in the vaccine theory waned, she said, but remained in the back of her mind.

When Michaela was 5, Cossolotto’s youngest daughter was born with Down syndrome. At times the pressure seemed unbearable as she struggled to care for two special-needs children.

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. “At this time, I do not have a unifying diagnosis to explain her problems,” the specialist, who practices in Iowa, wrote.

Neither did Michaela’s doctor at Mayo, who suggested a referral to Elaine Wirrell, the hospital’s new pediatric epileptologist, a neurologist who specializes in treating children with epilepsy. “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.

“I thought, ‘Oh, more bloodwork; we’re going to rule out another diagnosis,’ ” Cossolotto recalled.

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.

In many cases Dravet emerges when a baby runs a fever, which can occur after receiving an immunization. But, notes Wirrell, chief of pediatric epilepsy at Mayo, “it’s absolutely not the immunization causing Dravet” but rather the fever that causes the existing disorder to surface. Wirrell, who has seen 20 children with Dravet, said that those who have never been immunized show symptoms after spiking a fever.

Several recent studies have explored the relationship between the DPT vaccine and Dravet, which was first suggested as a cause of neurological problems in a 2006 study by a team of Australian epilepsy specialists. A 2010 study in Lancet Neurology found that the vaccine did not affect the outcome of Dravet: Babies whose seizures began after the shot fared no worse than those whose illness surfaced at another time. A 2011 report in the journal Pediatrics found that five children presumed to have neurological damage caused by the DPT shot were later discovered to have Dravet.

In Michaela’s case, the combination of seizures that began at six months, soon after the DPT shot, and the lack of any other cause made Wirrell suspect Dravet; the gene test confirmed it, although about 30 percent of children with Dravet do not test positive.

For Cossolotto, the diagnosis meant coming to terms with the reality of her daughter’s serious, incurable illness. “I always thought that if I knew what it was, we could fix it,” she said. “But it was Dravet, and there was no fixing it. I had to keep telling myself, ‘You have an answer.’ ”

“Five or 10 years ago, many people were not thinking that this is a seizure syndrome,” Wirrell said. She credits parents, especially Cossolotto, who since 2008 has been president of the support and advocacy group called, with raising awareness of the disorder and promoting effective treatment.

Epileptologists, she added, are attuned to Dravet, while general neurologists may be unfamiliar with it. “Recurrent prolonged seizures fairly early in life should trigger a referral to a pediatric epileptic specialist,” she advised.

As a result of the diagnosis and proper medication, Michaela’s life has dramatically improved. Although she still grapples with cognitive and behavioral 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.

Without a diagnosis, Cossolotto said, she would probably still believe — erroneously — that the DPT shot caused Michaela’s illness. “I understand this is a genetic condition,” she said. “Having an answer does make a difference.”