It is sometimes difficult for surgeons to diagnose neurological lesions of the shoulder, with which some patients visit the division of shoulder sugery. The purpose of this paper is to present the characteristics of physical and other examinations of neurological lesions among shoulder disfunctions. The clinical materials are twelve cases with dissociated motor loss syndrome, two neuralgic amyotrophy, one suprascapular entrapment neuropathy and one accessory nerve lesion. Diagnosis of these conditions is sometimes very complicated and over-looked, because these neurological lesions demonstrate only motor weakness and muscular waste, and do not manifest sensory disturbances.
In dissociated motor loss syndrome, eleven out of twelve cases showed motor weakness of the biceps humeri muscle combined with disturbance of shoulder motion. One of them, who had a combined massive cuff tear, underwent simultaneous operations of cervical spine and cuff repair. Surgeons must be careful of this combined condition because these two diseases mostly occur in the same generation. The clinical course of neuralgic amyotrophy is characterized by a severe pain which appeared suddenly, however, rotator cuff tear and cervical lesions should be differentiated from it. Not only needle electromyogram but also conduction studies were very helpful in identifying the impaired levels and degrees in cases with peripheral nerve lesions of the shoulder girdle, suprascapular nerve entrapment and accessory nerve injury. The authors emphasize that electrophysiological studies should be utilized more often in diagnosing shoulder disfunctions.
