The literature data of the last three decades on the problem of comorbidity of multiple sclerosis (MS) and epilepsy have been analyzed, such as issues of pathogenesis, clinical course, prognosis, and treatment of this dual pathology. Epileptic seizures occur in 2–3% to 5.9% of patients with MS, which is 3–6 times more common than in the general population. The incidence of epilepsy raises with increasing duration and severity of MS, with its
progressive course, and also depends on the effect of drugs for the treatment of MS. There is no unanimity in the literature on the age and gender characteristics of the occurrence of  epileptic seizures in MS. Probable mechanisms of MS comorbidity and epilepsy are analyzed. Data on certain common pathophysiology of MS and epilepsy and the concept according to which the model of epilepsy in MS is considered as a network disease are presented. Data on clinical manifestations and diagnosis of comorbid MS with epilepsy are presented. Epileptic seizures can occur at any stage of MS: before the clinical manifestations, at the onset of the disease, in the late stages, or can indicate exacerbation of MS. Types of epileptic seizures with a dual diagnosis (MS + epilepsy) are diverse. The majority of patients (up to 87.5%) have focal seizures (aware or unaware) or focal seizures to bilateral tonic-clonic, and a small share of patients have seizures of unknown origin. Most researchers believe that patients with MS and epilepsy have a more severe MS course and a worse long-term prognosis. The main directions of MS treatment and the impact of such treatment on the development of epileptic seizures are highlighted. Data on the effect of some disease-modifying drugs for the treatment of MS on the course of epilepsy and, on the other hand, on the impact of some antiseizure medications on the course of MS are presented. It is concluded that patients with MS have individual profiles and interindividual variability of epileptogenicity. The principles of treatment of epileptic
seizures/epilepsy in patients with MS are proposed.