6. Development of a new expression manner of gait using Lissajous figures 2—Application to abnormal gait

The usefulness of the electrophysiological tests on the differentiation of the affected regions (either the nerve root or the anterior horn of the spinal cord) of cervical spondylotic amyotrophy (CSA) was examined on 14 patients with proximal type and 3 patients with distal type CSA. The compound muscle action potentials (CMAP) stimulated at supramaximal Erb point were recorded from the proximal (deltoid and biceps) and distal muscles (extensor digitorum and abductor digiti minimi), and central motor conduction time (CMCT) was calculated from motor evoked potentials and F wave. CMAP was correlated with the manual muscle testing. In distal type CSA patients, decrease in CMAP was observed from both of the distal and the proximal muscles. The delayed CMCT and F wave abnormalities, which suggests the anterior horn legions, were found in 5 proximal and all distal type CSA patients. Furthermore 4 patients with poor prognosis out of 8 operated cases showed the delayed CMCT. Thus, these electrophysiological tests appear to be useful not only to differentiate the affected regions in CSA patients but to predict the prognosis after operation.