The Study Of Motor Evoked Potential In Parkinson's Disease By Transcranial Magnetic Stimulation

Objective:To explore the characteristics of motor evoked potential(MEP)and cortical excitability in Parkinson's disease by transcranial magnetic stimulation(TMS).Methods:20 normal volunteers were enrolled as control(Group A),whose average age is 62.3±16.7 years old ranged from 52 to 79 years old including 12males,8 females.MEP were assessed and compared separately between left and right hemispheres.30 patients with PD were performed in this study and they were divided into two groups.Group B and Group C.Group B includes 9 patients without therapy,whose average age is 62.7±17.3 years old ranged from 42 to 80 years old including 5 males,4 females.MEP and unified PD rating scale motor score(UPDRS)were assessed and compared separately before and after the therapy of L-DA.Group C includes 21 patients with therapy and asymmetry symptoms,Whose average age is 63.3±16.7 years old ranged from 46 to 80 years old including 12 males,9 females.MEP were assessed and compared separately on the minor side and the serious side,compared to the control by statistics.Results:1)The indexes of MEP from both sides of normal control have no significant diversity.2)In group B,relaxed motor threshold(RMT) increased and UPDRS decreased significantly after the therapy.Cortex latency(CL),amplitude(Amp)and central motor conduct time(CMCT) changed without significant diversity.3)RMT decreased,Amp increased and CL decreased significantly in PD patient compared to the normal control.4)On the serious side of PD,RMT decreased significantly compared to the minor side.Amp,CL and CMCT changed without significant diversity between minor side and serious side.Conclusion:The motor cortical excitability increased in PD patients.The excitability is higher while the symptom is more serious.It can be decreased by the therapy of L-DA.The character of MEP in PD patients can be helpful to diagnose and evaluate the severity of symptom.