Multiple sclerosis and epilepsy – the complex relationship
Aleksandra Waszczuk, Konrad Rejdak
Multiple sclerosis is one of the most common chronic neurodegenerative diseases of the central nervous system with autoimmune background. The prevalence of epileptic seizures in patients with multiple sclerosis ranges from 0.5% to 10%, while in the general population it ranges from 0.5% to 1%. Clinical studies have proved that all types of epileptic seizures may occur in the course of multiple sclerosis. Yet, it needs to be remembered that not all seizure symptoms are consistent with epileptic seizures. Non-epileptic seizures include tonic spasms (paroxysmal dystonias), paroxysmal akinesias and paresthesias, and trigeminal neuralgia. According to the literature of the subject, the majority of the available antiepileptic drugs have been broadly used for management of seizures in multiple sclerosis patients. However, there is a group of medications registered for multiple sclerosis treatment, that can in isolated cases slightly lower the seizure threshold thus causing or strengthening episodes of epileptic seizures. They include 4-aminopyridine and baclofen used for supportive therapy of multiple sclerosis, and according to some sources also immunomodulatory drugs such as interferon beta. The latest research has shown sodium channel blockers such as lamotrigine and phenytoin to potentially assist neuroprotection by inhibiting axonal degeneration that underlies the impaired mobility in multiple sclerosis patients. Additionally, phenytoin has found its application in the therapy of optic neuritis, also in the course of multiple sclerosis. Multiple sclerosis is indisputably a disease whose course eludes clear prognosis, whereas the coexistence of epileptic seizures and the clinical multiple sclerosis symptoms frequently poses both diagnostic and therapy-related challenges for the treating physicians.