Motor cortex excitability in Parkinson's disease and multiple system atrophy / 中华物理医学与康复杂志

ABSTRACT

Objective To observe any differences in motor cortex excitability between Parkinson's disease (PD)patients and patients with multiple system atrophy (MSA) and to explore whether motor evoked potentials (MEPs) can be used as an electrophysiological indicator for differentiating the 2 diseases.Methods Thirty-four PD patients, 22 MSA patients and 15 age- and sex-matched healthy control subjeets were included in this study. Relaxed motor thresholds (RMTs), central motor conduction time (CMCTs) and MEP amplitudes (AMPs) were recorded in all three groups. The relationships of RMT, CMCT and AMP with the severity of the disease were observed.Results Average RMT in the PD group was significantly lower than that in the MSA and control groups. Average RMT in the MSA group was also significantly lower than that in the control group. There was no significant difference among the three groups with regard to CMCT. AMP in the PD group was significantly higher on average than in the MSA and control groups, but there was no significant difference between the MSA and control groups. RMT decreased and CMCT shortened progressively with the severity of the disease in the PD group, but not in the MSA group.Conclusions There were differences in motor cortex excitability between PD patients and MSA patients. MEP RMTs and CMCTs may be valuable for identifying PD and MSAc but the clinical significance of the amplitude differences remains to be further explored.