<p>This review of the Russian and international literature examines the factors and characteristics of the development of epilepsy in multiple sclerosis (MS). The following are regarded as causes of epileptic seizures: acute focal brain tissue damage with edema and irritation of the cerebral cortex, systemic neuroinflammation with impaired ion-electrolyte and neurotransmitter metabolism and the influences of cytokines, secondary neurodegenerative changes with metabolic and disorders of neurotransmitter metabolism in long-term MS patients, comorbid diseases, the effects of drugs modifying the course of MS on the development of epileptic seizures, and the independent combination of epilepsy and MS. MRI is the gold standard for the diagnosis of MS, though it does not detect axonal-dendritic damage, so there is a need for research into new imaging methods. Neuroplastic changes in epilepsy and MS can be both adaptive and maladaptive, such that a search for therapeutic interventions enhancing the former and inhibiting the latter is needed, and this must take account of the mechanisms of neuroplasticity in both epilepsy and MS.</p>