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Electrodiagnosis of deep palmar ulnar neuropathy at the pisohamate hiatus
Author(s) -
Katirji B.,
Dokko Y.
Publication year - 1996
Publication title -
european journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 124
eISSN - 1468-1331
pISSN - 1351-5101
DOI - 10.1111/j.1468-1331.1996.tb00235.x
Subject(s) - medicine , ulnar nerve , ulnar neuropathy , anatomy , decompression , weakness , surgery , electrodiagnosis , elbow , cardiology
We present the clinical and electrophysiological findings of four patients with distal ulnar nerve lesions affecting, selectively, the deep palmar branch at the pisohamate hiatus. All presented with hand weakness and wasting, sparing the hypothenar muscles, without sensory manifestations. Two had palm pain. Three had possible precipitating trauma to the hand. All improved: three following decompression of constricting bands at the pisohamate hiatus and one spontaneously. At diagnosis, the ulnar motor amplitudes recording first dorsal interosseus (1st DI) were absent or very low. Recording the abductor digiti minimi (ADM), the amplitudes were normal or borderline. Needle EMG showed fibrillations and loss of motor unit potentials in all ulnar‐innervated muscles in the hand, except the ADM. Follow‐up ulnar conduction studies showed significant improvement of amplitudes recording 1st DI. Based on our cases and analysis of the literature, we conclude that lesions of the deep palmar branch of the ulnar nerve, distal to the branch to the ADM, are frequently caused by compression at the pisohamate hiatus, second only to compression by a ganglion. When treated surgically, this disorder carries good prognosis.