Cycling, Walking Also Risky in People with Epilepsy

— Rates higher than for car accidents, and independent of seizure meds

MedicalToday

Serious pedestrian, bicycling, and automobile accidents are more common in people with epilepsy, but the risks are independent of seizure medications, reported researchers in Sweden.

Epilepsy was linked to a 1.4-fold increased risk in overall serious transportation accidents -- a 2.2-fold increased risk in pedestrian accidents, a 1.7-fold increased risk in bicycle accidents, and a 1.3-fold increased risk in car accidents -- compared with controls, reported Helene Sundelin, MD, PhD, of Linkoping University Hospital, and colleagues online in .

Action Points

  • Note that this Swedish population-based study found that epilepsy was associated with a significantly increased risk of transportation accidents, but this risk was not modified by use of anti-epileptic medication.
  • Given the unique differences in the use of non-automotive transport in the Swedish population, these results may not be broadly generalizable to other populations.

"Transportation is important for taking part in the community," Sundelin told : "There's a need to explore the factors behind the increased risks of accidents for the different types of transportation" and to treat dysfunctions that might affect attention and executive functions in people with epilepsy.

This is the largest study to date that compares accidents among epilepsy patients and a control population, observed Vineet Punia, MD, MS, of the Cleveland Clinic, who was not involved with the research.

"This study provides a lot of key patient counseling metrics to neurologists," he noted. "Now, we know the risk of pedestrian and cycling accidents is, in fact, higher among people with epilepsy compared to car accidents. This finding is a critical addition to the literature as the trend for cycling becomes more common."

For the study, Sundelin's team identified 29,220 individuals 18 years or older with epilepsy and 267,637 matched controls from Sweden's National Patient Register (NPR), excluding people with cerebral palsy or intellectual disability. The main outcome measure was serious transportation accidents, defined in the NPR or Swedish death registry as an emergency visit at a hospital or a death.

The researchers followed the nationwide cohort from 2006 to 2013 to analyze the risk of serious transportation accidents and compare the risks during periods of medication and non-medication in the same patient, adjusting for civil status, employment, education, living area, psychiatric disorders, and psychotropic medication.

Most patients (75.3%) with epilepsy received anti-seizure drugs. Among epilepsy patients, 24.1% had an earlier psychiatric disorder, compared with 6.3% of the controls. Antidepressants were the most common psychotropic medications (17.6%) in epilepsy patients, followed by hypnotics/anxiolytics (15.0%).

After adjusting for confounders, people with epilepsy showed significantly higher rates of serious transportation accidents (HR 1.37, 95% CI 1.29–1.46). Increased risks occurred in pedestrian accidents (HR 2.24, 95% CI 1.69–2.97); bicycle accidents (HR 1.68, 95% CI 1.49–1.89); and car accidents (HR 1.31, 95% CI 1.19–1.44).

There were no significant differences in accident rates during epilepsy medication periods compared with non-medication periods, in within-individual comparisons or at the population level. HRs of patients with levetiracetam/lamotrigine monotherapy or oxcarbazepine/carbamazepine monotherapy did not differ from the main analysis.

Most previous studies have focused on the increased risk of motor vehicle accidents in epilepsy; that risk may be underestimated because patients fear losing driving privileges, noted Stephan Eisenschenk, MD, of the University of Florida, who was not involved in the study. The higher risks of cycling and pedestrian accidents shown in this study are important, because patients are more likely to report accidents not related to driving, he told . "If non-vehicular accidents are reported during clinic visits, physicians should counsel patients with epilepsy who are driving that there is also a concurrent higher risk for motor vehicle accidents."

Driving restrictions for epilepsy patients throughout the United States, wrote Allan Krumholz, MD, of the University of Maryland, and Anne Berg, PhD, of the Ann & Robert H. Lurie Children's Hospital of Chicago, in an .

Rationales for safe driving often are based on the risk of a seizure occurring after a defined period of being seizure-free, Krumholz and Berg observed, adding that the study is valuable because it looks at "the potential association of accident risk with anti-seizure medications and also adjusts for psychiatric comorbidity, which itself may play a role in the risk of accidents."

The researchers noted that none of the databases used in the study included driver's license information, and it was not possible to determine whether people involved in accidents were driving, had seizures while driving, or caused accidents. This held true for both individuals with epilepsy and controls. And only accidents that resulted in emergency hospital visits or death were included in the analysis, not minor accidents.

Disclosures

The research was funded by the Swedish Research Council for Health, Working Life, and Welfare and the Swedish Initiative for Research on Microdata in the Social and Medical Sciences.

The researchers reported relationships with Eli Lilly, Shire, Actavi, CURE, GSK, UCB, Eisai, Bial, and Novarti.

The editorialists reported no relevant relationships.

Primary Source

Neurology

Sundelin H "Epilepsy, antiepileptic drugs, and serious transport accidents" Neurology 2018; DOI: 10.1212/WNL.0000000000005210.

Secondary Source

Neurology

Krumholz A and Berg A "Epilepsy and transportation" Neurology 2018; DOI: 10.1212/WNL.0000000000005197.