Evaluation of cognitive functions and vep (visual evoked potentials) in myasthenia gravis patients

Myasthenia Gravis (MG) is a disease in which autoantibodies cause structural and functional changes in the postsynaptic membrane in the neuromuscular junction, resulting in impaired neuromuscular transmission and, as a result, increased weakness in the muscles with fatigue. MG affects the oculobulber muscles and limb muscles. While MG is widely considered a disorder of the neuromuscular junction, the central nervous system (CNS), heart and smooth muscles are not affected. In this study, it was aimed to assess whether there was central influence in MG by evaluating the differences between cognitive function scores and VEP results between patients diagnosed with MG and normal healthy population. Montreal Cognitive Assessment Test(MoCA), visual aural digit span test (Vads) and Stroop test were performed with the help of a psychologist to evaluate the cognitive functions of MG and the control group. VEP examines were performed in the control group and MG. A total of 61 patients were enrolled in the study, including 30 MG and 31 healthy controls. In terms of MoCA test results, control group performed worse than those with MG at the MoCA 9 score, resulting in a statistically significant difference(p= 0.043). No statistically significant differences were found between the groups in the MoCA total score and other MoCA test subtitle scores (MOCA total score p= 0.124). A statistically significant difference was found between the groups in terms of Stroop 2. section score, and the test completion time was longer in the control group( Stroop 2 duration p= 0.017). No statistically significant differences were found between both groups for other Stroop test episode scores. In the MG group no statistically significant differences were found in Stroop test duration between the subgroups in terms of myasthenia type , antibody type, Myasthenic Crisis status, presence of thymic pathology and treatment subgroups. According to the myasthenia type, it was found that the ocular myasthenia group was associated with statistically better test scores compared to the generalized group in auditory stimulation (p= 0.033), visual stimulation (p= 0.035), and written expression (p= 0.004) in the Vads test. There was no statistically significant difference in the duration and amplitudes of P100 latencies of VEP examinations between MG and control groups. As a result, in this study in which we investigated whether the central nervous system is affected or not in patients with Myasthenia Gravis, it was found that the MG group and control group performances were generally resembling at those exacuted cognitive tests and there were no significant differences in VEP results. The fact that the generalized myasthenia group performed worse on some cognitive test scores than ocular myasthenia does not provide us with accurate data, but suggests that a bad course of the disease may be associated with this condition. It is necessary to consider the assumption that patients can be protected from their effects on both the central and peripheral nervous systems with effective treatment of the current disease.