麻豆传媒

Focal epilepsy patients with hard-to-detect, subtle seizures experienced long delays to diagnoses and treatment, and those delays were tied to a high occurrence of motor vehicle accidents, a cross-sectional study showed.

Among 246 focal epilepsy patients with subtle, non-motor seizures, median time to diagnosis from their first reported seizure was 616 days, reported Jacob Pellinen, MD, of the University of Colorado School of Medicine in Aurora, and co-authors. In contrast, median diagnosis for 201 patients with disruptive motor seizures occurred in 60 days (P<0.001).

Proportions of patients who experienced injury before being diagnosed and the severity of those injuries were similar between the two groups. However, 19 of 23 (82.6%) motor vehicle accidents happened among people with undiagnosed subtle seizures, they wrote in .

"The findings highlight the fact that non-motor seizures are poorly recognized by patients, families, and medical professionals," Pellinen said. "Improving recognition could help close this treatment gap."

Undiagnosed subtle seizures may include brief hallucinations or déjà vu episodes and are not benign, Pellinen pointed out. "The vast majority of pre-diagnostic motor vehicle accidents in our study occurred in people with undiagnosed non-motor seizures," he told 麻豆传媒. "This has not been previously reported, and has significant implications for the health of people with new-onset epilepsy and the communities in which they live."

"Driving safety is of major importance to quality of life in people with epilepsy," noted Hal Blumenfeld, MD, PhD, of Yale University in New Haven, Connecticut, who wasn't involved with the research. "These new findings shed light on a previously unknown cause of car accidents in people who do not yet know they have epilepsy."

The study analyzed data from participants enrolled in the from June 2012 through November 2017. The project included 34 participating epilepsy centers and outpatient clinics in the U.S., Canada, Europe, and Australia.

Participants were referred within 4 months of treatment for newly diagnosed focal epilepsy. A total of 447 patients completed enrollment data for this analysis.

"To determine whether treatment initiation was effective, we obtained a very thorough history of pre-enrollment seizures of these patients," said co-author Jacqueline French, MD, of NYU Comprehensive Epilepsy Center in New York City. "It quickly became evident that many patients experienced a long delay to diagnosis, and therefore to treatment."

The researchers grouped patients by initial seizure semiology into two categories: subtle seizures (primarily motor arrest or focal aware without motor) or disruptive seizures (primarily motor activity or verbal output, including generalized tonic-clonic seizures). Demographic characteristics were similar between the two groups. Most patients were women and the average age at seizure onset was 30.

More patients with new-onset focal epilepsy presented with initial subtle seizures than with disruptive seizures (55% vs 45%, P=0.001). Two-thirds of patients with initial subtle seizures (67.5%) were not diagnosed until they developed seizures with disruptive features, including bilateral tonic-clonic seizures.

About 72% of patients with initial subtle seizures had preserved awareness, while 90% of patients with initial disruptive seizures had loss of awareness. Patients with subtle seizures and preserved awareness were diagnosed in a median of 801 days.

Before diagnosis, 40.7% of people with subtle seizures experienced injuries, as did 49.3% of patients with disruptive seizures; the difference between groups was insignificant. However, most potentially preventable motor vehicle accidents (MVAs) occurred in patients with initial subtle seizures (P<0.001).

"Although our study does not prove that earlier treatment would prevent injuries including MVAs or progression from non-motor to motor seizures, it highlights this as an important area for further investigation," Pellinen and colleagues noted.

"As a conservative assessment, among the U.S. population between the ages of 12 and 60 years (as in our study), and considering the annual incidence of epilepsy to be approximately 67.77 per 100 000 persons, there are about 142 500 cases of new onset epilepsy each year," they wrote.

"Approximately half of cases begin in driving-aged people, and about 60% of these epilepsies are focal. Based on our findings, there are approximately 1,816 MVAs every year in the USA alone due to undiagnosed non-motor focal seizures," they continued. "Notably, our study would not have enrolled people who died during an MVA or who had severe injury, and we relied on participants to disclose MVAs, so the number may actually be the tip of the iceberg."

Although the Human Epilepsy Project database collected in-depth seizure semiology information, one limitation is that it relied on patient-reported retrospective data from months or years before diagnosis, the researchers said. This may have underestimated the frequency of subtle events for which patients did not seek evaluation and the number of prior injuries, especially minor ones, in undiagnosed patients.

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