[The clinical significance of the F-wave of upper limb on cervical myelopathy].
The physiological characteristics of F-wave on the evoked EMG has been investigated and the utility of the objective index on cervical myelopathy was discussed. The wave pattern of F-wave varied each time, but the resembling wave shapes could be recognized while series of recording was done. The latency and amplitude of F-wave in resembling wave-shapes were equal. The F-wave could therefore be differentiated into several wave patterns. The wave patterns of the pathologic cases were almost the same as normal patterns. There is no any meaningful difference in conduction velocity between the normal and abnormal cases. Concerning the amplitude and the frequency of occurrence, the utilities are recognized. There has been a tendency in parallel with the severity of myelopathy, the more severe was the involvement, the more frequently occurred the big F-waves. It was also related to the motor function of the extremities and the degree of the acceleration of tendon reflex. Moreover, along with the postoperative improvement of the clinical symptoms, the occurrences of big F-wave approached that in normal cases. Apparently, the F-waves well reflected the clinically abnormal state. In other word, under the discussion of the amplitude and frequency, the F-wave of upper limb is believed to be useful as an objective index in cervical myelopathy.
D000293:Adolescent; D000328:Adult; D000368:Aged; D004576:Electromyography; D005121:Extremities / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009333:Neck; D013118:Spinal Cord Diseases / Q000175:diagnosis / Q000503:physiopathology*