Prognostic impact of epileptic seizures in multiple sclerosis varies according to time of occurrence and etiology

Abstract

Background and purpose Epileptic seizures occur more often in patients with multiple sclerosis (MS) than in the general population. Their association with the prognosis of MS remains unclear. This study was undertaken to evaluate whether epileptic seizures may be a prognostic marker of MS disability, according to when the seizure occurs and its cause. Methods Data were extracted from a population‐based registry of MS in Lorraine, France. Kaplan–Meier curves and log‐rank tests were used to compare the probability of different levels of irreversible handicap during the course of MS in patients who experience epileptic seizures or do not, according to the chronology and the cause of the first epileptic seizure. Results Among 6238 patients, 134 had experienced at least one epileptic seizure (2.1%), and 82 (1.2%) had seizures secondary to MS. Patients with epileptic seizure as a first symptom of MS (14 patients) had the same disease progression as other relapsing–remitting MS patients. Patients who developed epileptic seizures during the course of MS (68 patients) had a higher probability of reaching Expanded Disability Status Scale = 3.0 (p = 0.006), 6.0 (p = 0.003), and 7.0 (p = 0.004) than patients without an epileptic background. Patients with a history of epileptic seizures unrelated to MS also had a worse prognosis than patients without an epileptic background. Conclusions Epileptic seizures might be viewed as a “classic MS relapse” in terms of prognosis if occurring early in MS, or as a marker of MS severity if developing during the disease. Epileptic diseases other than MS may worsen the course of MS.

Epileptic seizures at multiple sclerosis onset and their role in disease progression

“…These results are somewhat different compared to very recent data showing no different disease progression in MS patients with an initial epileptic seizure compared to controls. 11 Unlike to our cohort, the cohort investigated by Selton et al only included patients with preexisting (although very moderate) disability with an EDSS of 1. We here demonstrated that patients with an abnormal neurological status as measured by the EDSS, compared to patients without any deficit, that is, monosymptomatic, has an influence on the long-term prognosis, which might at least in part explain the different results.…”

“…3 The effect of epileptic seizures at the onset of MS on disease progression has rarely been investigated so far. In a very recent study by Selton et al, 11 MS patients with epileptic seizures at the onset of MS did not have a different disease progression compared to the MS control group.…”

“…The overall group of MS patients with seizures at onset did not show a different disability in the long-term comparison, which is in line with very recent data. 11 Furthermore, dividing the group of MS patients with seizures at onset into the polysymptomatic and monosymptomatic subgroups revealed different results in the long-term progression. In the polysymptomatic group, including patients with additional neurologic symptoms besides seizures at MS onset, most symptoms at onset and all symptoms at the last examination were more frequent compared to the control group, leading to a higher EDSS at the last visit.…”

“…In the only study with data on EDSS in a group of patients with epileptic seizures as the first event of MS, the mean EDSS was 1.0, suggesting at least a minimal structural alteration. 11 Whether the presence of clinically measurable disability has any implication on the long-term disability progression remains unknown.…”

“…11 Unlike to our cohort, the cohort investigated by Selton et al only included patients with preexisting (although very moderate) disability with an EDSS of 1.…”