Epilepsy and Multiple Sclerosis: Is There a Link?
Allen and colleagues examined 2 record-linked statistical data sets from England: Hospital Episode Statistics (HES) (1999-2011) and the Oxford Record Linkage Study (ORLS) (1963-1998). After establishing admissions for multiple sclerosis, they searched the linked database for epilepsy as an "outcome" condition, using G40-G41 and ICD-7, -8, and -9 codes. They also reversed the procedure, establishing admissions for epilepsy, and then looking for multiple sclerosis as an "outcome" condition.
Both databases provided similar results. When multiple sclerosis was the initial diagnosis, epilepsy was increased in the HES database by a relative risk of 3.3 (P < .001) and in the ORLS by a relative risk of 4.1 (P < .001). When epilepsy was the initial diagnosis, multiple sclerosis was increased in the HES cohort by a relative risk of 1.9 (P < .001) and by 2.5 (P = .001) in the ORLS.
The knowledge that epilepsy and multiple sclerosis occur together more frequently than by chance should heighten vigilance for both when diagnosing or treating patients with either condition. For example, unexplained cognitive symptoms in a patient with multiple sclerosis may turn out to be partial complex seizures, whereas an episode of painful blurry vision in someone with epilepsy could indicate optic neuritis as the first symptom of multiple sclerosis. If seizures require treatment, an antiepileptic drug should be chosen that does not exacerbate preexisting symptoms of multiple sclerosis, such as ataxia, tremor or impaired cognition.
More research needs to be done to investigate the underlying reasons for the increased incidence of epilepsy in patients with multiple sclerosis, as well as an increased incidence of multiple sclerosis in patients with epilepsy. Inflammatory cortical demyelination in multiple sclerosis could cause neuronal loss and seizures. Could an inflammatory pathogenesis of epilepsy also lead to multiple sclerosis? As research continues to progress very rapidly in both of these disease states, maybe we won't have to wait long to find out.
Analysis of Hospitalizations for Multiple Sclerosis and Epilepsy
Allen and colleagues examined 2 record-linked statistical data sets from England: Hospital Episode Statistics (HES) (1999-2011) and the Oxford Record Linkage Study (ORLS) (1963-1998). After establishing admissions for multiple sclerosis, they searched the linked database for epilepsy as an "outcome" condition, using G40-G41 and ICD-7, -8, and -9 codes. They also reversed the procedure, establishing admissions for epilepsy, and then looking for multiple sclerosis as an "outcome" condition.
Both databases provided similar results. When multiple sclerosis was the initial diagnosis, epilepsy was increased in the HES database by a relative risk of 3.3 (P < .001) and in the ORLS by a relative risk of 4.1 (P < .001). When epilepsy was the initial diagnosis, multiple sclerosis was increased in the HES cohort by a relative risk of 1.9 (P < .001) and by 2.5 (P = .001) in the ORLS.
For Now, Heightened Vigilance Needed
The knowledge that epilepsy and multiple sclerosis occur together more frequently than by chance should heighten vigilance for both when diagnosing or treating patients with either condition. For example, unexplained cognitive symptoms in a patient with multiple sclerosis may turn out to be partial complex seizures, whereas an episode of painful blurry vision in someone with epilepsy could indicate optic neuritis as the first symptom of multiple sclerosis. If seizures require treatment, an antiepileptic drug should be chosen that does not exacerbate preexisting symptoms of multiple sclerosis, such as ataxia, tremor or impaired cognition.
More research needs to be done to investigate the underlying reasons for the increased incidence of epilepsy in patients with multiple sclerosis, as well as an increased incidence of multiple sclerosis in patients with epilepsy. Inflammatory cortical demyelination in multiple sclerosis could cause neuronal loss and seizures. Could an inflammatory pathogenesis of epilepsy also lead to multiple sclerosis? As research continues to progress very rapidly in both of these disease states, maybe we won't have to wait long to find out.