PECULIARITIES OF COMORBID PAIN SYNDROME AND COGNITIVE DYSFUNCTION IN PATIENTS WITH MULTIPLE SCLEROSIS

In this paper, we reviewed scientific sources on multiple sclerosis, analyzed the latest data on the peculiarities of cognitive dysfunction and comorbid pain syndrome in patients with multiple sclerosis. Multiple sclerosis belongs to the group of chronic progressive demyelinating diseases with a predominant lesion of the central nervous system. It affects over 2.5 million people worldwide and is considered as one of the most disabling neurological disorders. Symptoms range from physical ones including loss of vision, spasticity, bladder and bowel dysfunction, problems with walking and balance, fatigue and pain, to mental problems such as cognitive impairment, depression, and anxiety. Comorbid conditions have a significant impact on the quality of life of patients with multiple sclerosis. This evokes considerable scientific interest, since their presence can cause a delay in diagnosis, change the progression of neurological deficits, reduce physical activity and increase the severity of symptoms of the underlying disease. One of the most common comorbid conditions associated with multiple sclerosis is pain. The prevalence of pain syndrome ranges from 29% to 86%. Patients can consider pain as one of the first symptoms of multiple sclerosis. Moreover, in the treatment and diagnosis of multiple sclerosis, in most cases, the state of cognition is missed or neglected, but it always accompanies the patients in the form of cognitive disorders of varying severity. Cognitive function is understood as the most complex mechanism by which the process of rational cognition of the environment and interaction with it is carried out. Both a series of cognitive tests for multiple sclerosis and an MRI evaluation of gray matter atrophy can help to assess the state of cognition. Also, an additional diagnostic method is transcranial magnetic stimulation, with which it is possible to create a model for mapping the cerebral cortex using evoked motor potentials. Thus, the analysis of the literature has shown that the issues of the influence of comorbidity and cognitive dysfunction on the course of multiple sclerosis, the relationship of the onset of multiple sclerosis with comorbid conditions, and the correlation of neurological deficit with the cognitive ability of patients are not studied completely yet.