Pauline Anderson

December 13, 2017

WASHINGTON, DC — Lengthy delays in epilepsy diagnosis are contributing to preventable motor vehicle accidents, new research suggests.

Many doctors are not familiar with types of seizures other than those causing convulsions, Jacqueline French, MD, professor, NYU Comprehensive Epilepsy Center, New York City, told Medscape Medical News

"We think there should be better education for clinicians, as well as for the general public," she said. Such education would improve seizure recognition and reduce avoidable harm related to diagnostic delay, she added.

The findings were presented here at the American Epilepsy Society (AES) 71st Annual Meeting 2017.

Subtle Seizures

Researchers used prospective data on 173 participants from the Human Epilepsy Project (HEP), which follows patients aged 12 to 60 years with newly diagnosed focal epilepsy.

Using information from a standardized interview form, researchers classified subjects into those with "disruptive seizures," which included generalized tonic-clonic seizures, and those with what they called "subtle seizures."

"That doesn't mean they don't have alteration of awareness, it just means that they don't sort of shout or have a lot of motor activity during their seizure," said Dr French.

Of the 171 participants analyzed, 97 had initial presentations characterized by subtle seizures and 76 by disruptive seizures.

Researchers determined the time from onset of symptoms to diagnosis using seizure diaries and clinic notes. Median time to diagnosis was 337 days in patients with subtle seizures vs 110.5 days in those with disruptive seizures (P < .0001). 

"We found that a very large number of people go a very long time without a diagnosis," said Dr French.

Although patients with disruptive seizures were more likely to have impaired awareness than those with subtle seizures, the presence of impaired awareness did not affect time to diagnosis in either group.

All six of the automobile accidents that may have been avoided occurred in those with impaired awareness before seizure diagnosis.

"That's more than 5% of newly diagnosed patients who had car accidents that could have been avoided," said Dr French. "If you multiply that by all the people with newly diagnosed epilepsy in the US, we're talking a huge liability of auto accidents for those with undiagnosed seizures. I think that's a big deal."

If the seizures had been diagnosed earlier, two thirds could have been eliminated by antiepileptic drugs, said Dr French.

"Pretty much every study has shown a 66% treatment response in newly diagnosed patients."

Dr French added that the law in most states would have prevented these patients from driving after a diagnosis of epilepsy until they were seizure free for at least 6 months.

Many doctors — and patients, too — don't recognize that events not involving convulsive-type movements are, in fact, seizures, said Dr French.

"Most people are only aware of convulsive seizures and are not familiar with other types of epileptic seizures."

She used the example of a 30-year-old woman who since the age of 12 years had been having increasing episodes of "déjà vu and a rising epigastric sensation."

This patient wasn't referred to a neurologist until age 25, and even then wasn't diagnosed or treated. "At age 30, she had a typical episode while driving that was accompanied by loss of awareness, leading to a motor vehicle accident causing a head injury," said Dr French.

The woman became completely seizure-free with treatment. 

Missed Diagnoses

Commenting on the findings for Medscape Medical News, Michael Privitera, MD, professor, neurology, and director, Epilepsy Center, University of Cincinnati Gardner Neuroscience Institute in Ohio, said although the number of car accidents in the study was small, he agreed they were likely preventable with more timely diagnosis and treatment.

He said he liked the way the researchers distinguished between "subtle" and "disruptive" seizures. "This is not a widely accepted terminology, but in this situation it quite accurately describes the presentation."

The most "noteworthy" finding of the study was the high rate and long duration of undiagnosed symptoms, said Dr Privitera.

"Neurologists and epileptologists have all seen patients like this, but the magnitude of the problem is quite surprising."

It's not unusual for patients to come to the neurologist only after a "disruptive" seizure, usually a tonic-clonic seizure, said Dr Privitera.

"These patients have often reported symptoms to a non-neurologist who either ignores or evaluates the patient for an incorrect diagnosis — for example, a patient with recurrent abdominal symptoms as a focal aware seizure may get an extensive gastroenterological workup, whereas the problem is seizures."

The Epilepsy Foundation has received funding for seizure educational initiatives, some of which will be aimed at non-neurologists, for example, emergency department doctors, pediatricians, and primary care physicians, who may be the first to see patients. Dr Privitera is co-director of some of these programs.

Funding for the HEP database comes from a variety of sources, including the Epilepsy Study Consortium, UCB pharmaceuticals, Finding a Cure for Epilepsy and Seizures (FACES), Pfizer, Eisai, Lundbeck, Sunovion, the Andrews Foundation, the Vogelstein Foundation, and Friends of FACES. The researchers have disclosed no relevant financial relationships.

American Epilepsy Society (AES) 71st Annual Meeting 2017. Abstract 1.158. Presented December 2, 2017.

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