Unveiling the Impact of Seizures While Driving: A Retrospective Cohort Study on Type, Frequency, and Consequences in People With Epilepsy Prior to Diagnosis

Abstract

Impact of Seizures While Driving Prior to Diagnosis in People With Focal Epilepsy: Motor Vehicle Accidents and Time to Diagnosis

Bases B, Barnard S, French JA, Pellinen J. Neurology. 2023;101(13):e1370-e1375. doi:10.1212/WNL.0000000000207464. PMID: 37286361

Objective:

To identify the type, frequency, and consequences of seizures while driving (SzWD) in people with epilepsy prior to diagnosis.

Methods:

We performed a retrospective cohort study using the Human Epilepsy Project (HEP) to identify pre-diagnostic SzWD. Clinical descriptions from seizure diaries and medical records were used to classify seizure types and frequencies, time-to-diagnosis, and SzWD outcomes. Data was modeled using multiple logistic regression to assess for factors independently associated with SzWD.

Results:

32 pre-diagnostic SzWD were reported among 23/447 (5.1%) participants. Of these, seven (30.4%) had more than one. Six participants (26.1%) experienced a SzWD as their first-lifetime seizure. Most SzWD were focal with impaired awareness (n = 27, 84.4%). Of participants who had MVAs, six (42.9%) had no recollection. SzWD led to hospitalization in 11 people. Median time from first seizure to first SzWD was 304 days (IQR = 0-4056 days). Median time between first SzWD to diagnosis was 64 days (IQR = 10-176.5 days). Employment was associated with a 3.95-fold increased risk of SzWD (95% CI: 1.2-13.2, p = 0.03), and non-motor seizures were associated with a 4.79-fold increased risk (95% CI: 1.3-17.6, p = 0.02).

Significance and discussion:

This study identifies the consequences of seizure-related MVAs and hospitalizations people experience prior to epilepsy diagnosis. This highlights the need for further research aimed at improving seizure awareness and improving time to diagnosis.

Commentary

There are more than 200 000 new diagnoses of epilepsy a year in the United States. ¹ With a diagnosis of epilepsy, there are important safety precautions necessary including driving restrictions. However, there is often a delay in diagnosis of epilepsy, particularly with focal non-motor seizures ^2,3 and seizures may be misdiagnosed. This gap between onset and diagnosis leaves the patient unadvised regarding safety precautions, including driving. A recent study by Bases et al ⁴ found that 5% of individuals with focal epilepsy experienced seizures while driving (SzWD) prior to diagnosis of epilepsy. This study addresses a crucial concern in the realm of epilepsy and road safety, investigating the frequency and consequences of seizures occurring while driving in individuals with focal epilepsy before they receive an official diagnosis. Seizures while driving are a feared consequence of epilepsy, posing significant risks to individuals and public safety. While SzWD accounts for up to 1% of motor vehicle accidents (MVAs), this is considerably lower than accidents associated with distracted driving, speeding, substance use, or drowsiness. Nevertheless, considering the annual occurrence of 6 million MVAs in the United States and annual incidence of 200,000 new diagnoses of epilepsy, this issue remains significant. What makes SzWD particularly concerning is that these statistics represent cases after epilepsy diagnosis, leaving the contribution of undiagnosed epilepsy uncertain. This underscores the urgent need for timely epilepsy diagnosis and treatment to mitigate SzWD-associated risks.

Diagnostic and treatment delays have broad negative consequences on the quality of life, cognitive function, and overall well-being of individuals with epilepsy, increasing morbidity and mortality rates, including those resulting from MVAs and hospitalizations. Improving the time to diagnosis offers a potential means to reduce the occurrence of prediagnostic SzWD.

The authors aimed to determine how frequently seizures occur while driving before an epilepsy diagnosis and how long it takes for a person to be diagnosed. The methodology employed in this study involved a retrospective analysis of data from the Human Epilepsy Project (HEP), which spans multiple countries and provides a diverse dataset for analysis. The study included 447 participants diagnosed with focal epilepsy within 4 months of initiating treatment, categorized into 2 groups based on the initial seizure presentation: those with focal nonmotor seizures and those with focal seizures involving motor symptoms.

The study results revealed significant differences between these 2 groups, with individuals experiencing nonmotor seizures facing notably longer median times to diagnosis from their first seizure, emphasizing a concerning diagnostic delay. This finding aligns with earlier studies, underscoring the urgency of addressing diagnostic delays in epilepsy.

The data also provide information related to prediagnostic SzWD, including seizure and MVA descriptions. The authors identified 23 people (5%) who had one or more SzWD, totaling 32 seizures before diagnosis. Among these individuals, 7 (30%) experienced multiple SzWD incidents, and for 6 (26%), the seizure while driving was their first-ever seizure. Most SzWD incidents were focal with impaired awareness (n = 27, 84.4%). Among participants who had MVAs, 6 (42.9%) had no recollection. A 3.95-fold increased risk of SzWD was found in those employed (95% CI: 1.2-13.2, P = .03) and a 4.79-fold increased risk in those with non-motor seizure (95% CI: 1.3-17.6, P = .02). Those with non-motor seizures also experienced longer delays between first seizure and diagnosis. The median time from experiencing the first seizure to experiencing a seizure while driving was 304 days, while the average time from the first seizure while driving to an epilepsy diagnosis was 64 days. Notably, individuals with non-motor seizures experience longer delays in diagnosis, underscoring the need for early recognition of diverse seizure types.

There were 19 MVAs (59%) and 11 hospitalizations for injuries (34%), such as tongue bite, dislocated thumb, fractured sternum, cerebral hemorrhage, and near-drowning, highlighting both the physical and financial toll of SzWD. It is important to note that these percentages may underestimate the true incidence due to limitations in self-reporting of historical events.

The authors’ estimate of nearly 6500 people experiencing prediagnosis SzWD annually in the United States alone may be an underestimate since some participants’ seizure history was self-reported, potentially leading to underreporting of SzWD incidents, and the data excluded patients over age 60.

This study documents the incidence and consequences of SzWD prior to diagnosis. It underscores the urgent need to improve nonmotor seizure recognition among both the general public and health care professionals to improve diagnosis of epilepsy and decrease diagnostic delay. ^{5 -7} Timely diagnosis and treatment are crucial in reducing the incidence of prediagnostic SzWD and its associated risks. Improved public health initiatives aimed at improving seizure recognition are needed to reduce the impact of epilepsy and improve the safety and quality of life for individuals with epilepsy.

Tracey A. Milligan, MD, MS, FAES, FANA
Neurology,
New York Medical College School of Medicine