Assessment of Motor Unit Number Alteration in Paretic Muscles of Stroke Survivors

• 作 者: XiaoyanLi;WilliamZ.Rymer;PingZhou;
• 机 构: Department of Sensory Motor Performance Rehabilitation Institute of Chicago USA
• 出 处: 2011第二届国际神经科技大会
• 发表日期: 2011年期

　　The objective of this study was to assess whether there is evidence of spinal motoneuron loss in paretic muscles of stroke survivors, using an index measurement called motor unit number index (MUNIX).MUNIX, a recently developed novel neurophysiological technique by Nandedkar et al., provides an index proportional to the number of motor units in a muscle.The MUNIX technique was applied to the first dorsal interosseous (FDI) muscle bilaterally in stroke subjects.The area and power of the maximum M-wave and the interference pattern electromyogram (EMG) at different contraction levels were used to calculate the MUNIX.A motor unit size index (MUSIX) was also calculated using maximum M wave recording and the MUNIX values.We observed a significant decrease in both maximum M-wave amplitude and in MUNIX values in the paretic FDI muscles, as compared with the contralateral muscles.No significant difference was found in MUSIX values between the parctic and contralateral muscles.However, the range of MUSIX values was slightly wider for paretic muscles than the contralateral muscles.The findings from the index measurements provide further evidence of spinal motoneuron loss after a hemispheric brain lesion.