Distal ulnar neuropathy from carpal ganglia: a clinical and electrophysiological study.

The clinical and electrophysiological observations in two cases of distal ulnar neuropathy from carpal ganglia are reported. In the first case, the ganglion was compressing the ulnar nerve just proximal to its division; in the second case, the ganglion was compressing the deep branch of the ulnar nerve just at its origin. In both cases, both axonal degeneration and segmental demyelination were present. A clinical classification of the compression syndromes of the deep ulnar branch is proposed.