General points

Epilepsy affects four million people in the USA and five million in Europe. The severity and frequency of seizures differs from one individual to another and consists of a loss of contact with more or less important motor or sensory functions. Its treatment is essentially based on several drug combinations but between 26 and 50% of patients often have difficulty following these combinations correctly.

In the most severe form, epileptic seizures are continuous or overlapping and can lead to death if untreated.

Epilepsy affects four million people in the USA and five million in Europe. The severity and frequency of seizures differs from one individual to another and consists of a loss of contact with more or less important motor or sensory functions. Its treatment is essentially based on several drug combinations but between 26 and 50% of patients often have difficulty following these combinations correctly.

In the most severe form, epileptic seizures are continuous or overlapping and can lead to death if untreated.

Seizure on road

Nowadays, assessing the risk between this disease and driving is still difficult.
Most of the time conducting prospective studies faces ethical problems and previous observational and/or retrospective studies have found contradictory results.

As a matter of fact, this disease has a great heterogeneity of presentation. The presence of prodromes, the type and duration of seizure, the efficacy and compliance with various therapeutic combinations are different from one patient to another and makes comparing different studies’ populations really challenging.

On the one hand, CDC (Centers for Disease Control and Prevention) data on fatal accidents collected in the United States from 1995 to 1997 attributes only a few crashes (n=86 or 0.2%) to an attack.1

Conversely, in a retrospective cohort study comparing 159 epileptic patients with 559 control subjects, seven-times more patients were treated for post-crash trauma in the epilepsy group.2

Recently a large national Swedish cohort compared the accident rate between 29,220 epileptic patients (75.3% treated) and 267,637 control subjects. This indicator was 4.6% compared to 3.4% in controls, (i.e. 37% over-risk) without affecting the mortality rate (0.1% in both populations). In subgroup analyses, the presence and type of treatment had no pejorative influence.3

In 2012, Classen et al. analyzed 16 studies’ results on this topic. They classified them into three descending thresholds according to the quality of their execution and the level of evidence provided.4

They concluded:

  • A lack of indisputable level 1 studies.
  • From the level 2 classified studies’ data, epilepsy surgery, absence of seizures for 6 to 12 months, a low frequency of accidents unrelated to epilepsy and regular therapeutic adjustments would be some favorable elements for driving approval.
    A 6 to 12 months seizure-free period would be sufficient despite complementary data demonstrating a 93% risk reduction beyond 12 months; and others (Taylor et al) suggesting durations longer than 3 years.
    An anti-epileptic treatment would favor minor accidents but avoid severe injuries. Mandatory seizure reporting would have a minor positive effect and the presence of auras before seizures would not necessarily reduce the accidents risk.
  • Class 3 small numbers studies with few events would find seizure causality in accidents. Schematically young, licensed males would be most often involved.

In these conditions, driving remains highly regulated for these subjects currently..

Nowadays, assessing the risk between this disease and driving is still difficult.
Most of the time conducting prospective studies faces ethical problems and previous observational and/or retrospective studies have found contradictory results.

As a matter of fact, this disease has a great heterogeneity of presentation. The presence of prodromes, the type and duration of seizure, the efficacy and compliance with various therapeutic combinations are different from one patient to another and makes comparing different studies’ populations really challenging.

On the one hand, CDC (Centers for Disease Control and Prevention) data on fatal accidents collected in the United States from 1995 to 1997 attributes only a few crashes (n=86 or 0.2%) to an attack.1

Conversely, in a retrospective cohort study comparing 159 epileptic patients with 559 control subjects, seven-times more patients were treated for post-crash trauma in the epilepsy group.2

Recently a large national Swedish cohort compared the accident rate between 29,220 epileptic patients (75.3% treated) and 267,637 control subjects. This indicator was 4.6% compared to 3.4% in controls, (i.e. 37% over-risk) without affecting the mortality rate (0.1% in both populations). In subgroup analyses, the presence and type of treatment had no pejorative influence.3

In 2012, Classen et al. analyzed 16 studies’ results on this topic. They classified them into three descending thresholds according to the quality of their execution and the level of evidence provided.4

They concluded:

  • A lack of indisputable level 1 studies.
  • From the level 2 classified studies’ data, epilepsy surgery, absence of seizures for 6 to 12 months, a low frequency of accidents unrelated to epilepsy and regular therapeutic adjustments would be some favorable elements for driving approval.
    A 6 to 12 months seizure-free period would be sufficient despite complementary data demonstrating a 93% risk reduction beyond 12 months; and others (Taylor et al) suggesting durations longer than 3 years.
    An anti-epileptic treatment would favor minor accidents but avoid severe injuries. Mandatory seizure reporting would have a minor positive effect and the presence of auras before seizures would not necessarily reduce the accidents risk.
  • Class 3 small numbers studies with few events would find seizure causality in accidents. Schematically young, licensed males would be most often involved.

In these conditions, driving remains highly regulated for these subjects currently..

Références

  1. Sheth SG, Krauss G, Krumholz A, Li G. Mortality in epilepsy: driving fatalities vs other causes of death in patients with epilepsy. Neurology 2004;63:1002-7.
  2. Lings S. Increased driving accident frequency in Danish patients with epilepsy. Neurology 2001;57:435-9.
  3. Sundelin HEK, Chang Z, Larsson H, et al. Epilepsy, antiepileptic drugs, and serious transport accidents: A nationwide cohort study. Neurology 2018;90:e1111-e8.
  4. Classen S, Crizzle AM, Winter SM, Silver W, Eisenschenk S. Evidence-based review on epilepsy and driving. Epilepsy Behav 2012;23:103-12.