Man-in-the-barrel syndrome, a symmetrical proximal brachial amyotrophic diplegia related to motor neuron diseases: a survey of nine cases.

OBJECTIVE To report on 9 patients presenting with sporadic motor neuron disease , who over a long period of time evolved with a symmetrical proximal brachial amyotrophic diplegia. METHODS Nine patients were followed-up who , displayed, since onset, a progressive limitation of arm flexion/abduction resulting in a peculiar posture with both hands hanging loosely beside the trunk. Electrophysiological test results were consistent with lower motor neuron disease. Cervical MRI was performed in all patients. RESULTS Nine male subjects with ages ranging from 38 to 73 years at onset of symptoms, developed bilateral and symmetric paresis and atrophy of upper limb muscles. Proximal muscles were more involved than the distal groups. In most patients tendon reflexes were absent or hypoactive in the upper limbs. Needle electromyography (EMG) revealed positive sharp waves and fibrillations and high amplitude polyphasic potentials with an incomplete recruitment pattern in most upper limb muscles. EMG of lower limb muscles was normal in some cases while abnormal in others. MRC did not disclose cervical spinal cord abnormalities from C5-T1. CONCLUSION Attention is called to the Man-in-the-Barrel syndrome in some motor neuron diseases, especially in patients with progressive spinal atrophy and amyotrophic lateral sclerosis.