The report gives a more holistic picture of a highly studied by little understood issue in multiple sclerosis.
Seizures occur in 2% of patients with multiple sclerosis (MS) globally, and epilepsy occurs in 3% of patients, according to a new review article.
The report provides a more comprehensive and international picture of the co-incidence of MS with seizure/epilepsy, an issue that has been studied extensively on a smaller scale, but which remains shrouded in considerable mystery. The findings were published in International Journal of Preventive Medicine.
Seizure and epilepsy are known to be more prevalent in persons with MS than in the general population, although reports from different regions and countries have reached different prevalence conclusions, according to corresponding author Mahsa Ghajarzadeh, MD, MPH, PhD, of Tehran University of Medical Science, in Iran, and colleagues.
The investigators searched several scholarly databases in search of studies and abstracts looking at seizure and epilepsy in MS that were published up until October 2019. Nearly 5000 studies were identified. After eliminating duplicates, non–cross-sectional studies, and those not published in English, the authors had 39 studies and abstracts to include in their final analysis. The studies were published between 1972 and 2019, and the majority (29) were published in Europe.
Ghajarzadeh and colleagues found a pooled prevalence of seizure in MS cases of 2% (95% CI, 1%-3%), and a pooled prevalence of epilepsy of 3% (95% CI, 2%-4%). Rates varied significantly by continent.
Studies from Asia showed an epilepsy prevalence of 6%, while the prevalence was 3% in both Europe and America. The investigators said they did not believe that location was the cause of the heterogeneity, noting that “the level of heterogeneity decreased after subgroup analysis in Asian and American subgroups.”
The investigators said their findings align with previous research estimating the prevalence of epilepsy in MS being between 3.2% and 4%, which is roughly 4 times the rate of epilepsy in the general population. They said epilepsy could have a significant impact on disease progression, increasing the likelihood that relapsing-remitting MS becomes secondary-progressive MS. Epilepsy in MS has also been linked with more intensive cortical inflammation.
“Seizure/epilepsy can be the first symptom of MS, the incidence rate of which increases with the longer duration of the disease or the higher number of lesions,” they wrote. “However, no relationship has been found between the severity of MS and epilepsy.”
Turning to seizures, the authors said it is not yet known how they affect MS prognosis, and the issue remains highly controversial.
“The cause of seizure in MS is not clear; however, cortical and juxtacortical inflammation, demyelination, and atrophy are considered to play a role in the development of seizures/epilepsies in MS,” Ghajarzadeh and colleagues wrote.
More broadly, the authors said much remains unknown about the issue of seizures/epilepsy in MS. Seizures can occur at any time during MS, and all types of seizures have been reported. Some researchers have pointed to focal seizure followed by secondary progression as the most prevalent type of seizure in patients with MS, but others have found primary generalized tonic-clonic seizures to be the most common.
The investigators said patients with seizures are generally advised to take antiepileptic medications to prevent new seizures and status epilepticus.
Mirmosayyeb O, Shaygannejad V, Nehzat N, Mohammadi A, Ghajarzadeh M. Prevalence of seizure/epilepsy in patients with multiple sclerosis: a systematic review and meta-analysis. Int J Prev Med. 2021;12:14. Published 2021 Feb 24. doi:10.4103/ijpvm.IJPVM_75_20