Spinal cord affection, according to various sources, is a common complication of a new coronavirus infection. The article describes various variants of spinal cord pathology in COVID-19, their potential mechanisms of development, approaches to treatment and outcomes of the disease. Three patients who were observed at the Research Center of Neurology and represent the most interesting cases of classic transverse myelitis, myelitis with predominant involvement of the lateral and posterior cords, and longitudinal widespread myelitis associated with antibodies to myelin oligodendrocyte glycoprotein (MOG) are considered in detail. These clinical observations demonstrate the importance of early diagnosis and selection of adequate therapy for a favorable outcome of the disease.

The results of complex studies were used to formulate a concept of the development of neurological impairments in multiple sclerosis (MS). Acutely developing impairments to spike propagation, reaching the level of conduction blockade, due to the active pathological process with demyelinating and axonal damage to the CNS lead to the formation of neurological impairments in exacerbations of MS, while complete or partial reversion (regression) of these symptoms in the stage of remission results from compensatory changes in the nature of conduction, which were not, however, accompanied by recovery of electrophysiological measures. The development of stable neurological deficit in secondary-progressive MS is determined by impairments to spike conduction processes associated with significant levels of demyelination and atrophic changes in the CNS, with myelin loss and axon death. Finally, the severity of cognitive changes is determined by differences in the severities of both the focal demyelinating process and diffuse damage to brain substance in MS, including the neurodegenerative component. The main factor in transient increases in symptoms is the universal lability of electrophysiological parameters, including those developing on the background of ion and neurotransmitter imbalance.

An equal reduce of relapse rate in relapsing-remitting and secondary progressive multiple sclerosis (MS) has been revealed in the comparative study of betaseron, rebif-22 mkg and copaxone treatment during 3 years. The prevention of disability progression has been demonstrated in all therapeutic groups in relapsing-remitting MS and during rebif and copaxone treatment in secondary progressive MS. The side effects were less common for copaxone therapy comparing to other medications used. The reasons of the discontinuation of treatment are discussed.

A comparative analysis of efficacy and tolerability of such immunomodulating compounds as rebif 22-mcg and copaxone used in the treatment of multiple sclerosis is presented. The analysis was based on the data obtained in the 2-year study of copaxone (145 patients) and rebif 22-mcg (74 patients) therapy carried out in the Neurology Institute, Russian Academy of Medical Sciences.

Pathophysiological peculiarities of demyelinated axons determine their high sensitivity to different exogenous factors and are the reason of instability of neurological signs in MS. One of the typical MS sing is high sensitivity to elevated temperature of the body. Even temporary elevation in body temperature may cause changes in impulse conduction in demyelinated fibres, which was proved by studies of evoked potentials and stabilometric studies. These disturbances may be associated with disorder of ions channels function. The role of other factors (metabolic and immunological disturbances, levels of cytokines and neurotransmitters) in temporary block of nerve conduction in MS is discussed. Further studies of the mechanisms of the lability of neurological sings in MS may lead to elaboration of new approaches to MS treatment.