Implementation of the TMS in the early stages of Parkinson's disease

47 PD patients were investigated with the single-pulse TMS to find out changes in motor evoked potential and motor conduction related to the stage of minimal motor symptoms and its further deterioration in groups with the different clinical types of the disease. The investigation revealed a markedly longer MEP duration along with the increased number of phases, than in controls, which were bilateral and advanced despite the minimal unilateral motor symptoms. There was also increased MEP amplitude in facilitation, with a higher degree of asymmetry, compared to controls. Patients with predominant rigid clinical forms had the further MEP duration and amplitude increase proportionally to bradikinesia and rigidity in the early stages of the disease. Patients with tremor predominant forms had no further changes in the MEP duration and amplitude, but had their motor CCT decreased in the early stages. Patients with the akinetic form were characterized by the asymmetric increase in the MEP Amplitude in relaxation and motor CCT shortening. Thus, TMS allows us to diagnose early the possible central motor changes secondary to Parkinson's disease, reveals the difference in compensational capacity according to the clinical type of the disease and helps in monitoring of the severity of motor changes in early stages.