Wasting of the small hand muscles in upper and mid-cervical cord lesions.

Four patients are described with destructive rheumatoid arthritis of the cervical spine and neurogenic wasting of forearm and hand muscles. The pathological connection is not immediately obvious, but a relationship between these two observations is described here with clinical, radiological, electrophysiological and necropsy findings. Compression of the anterior spinal artery at upper and mid-cervical levels is demonstrated to be the likely cause of changes lower in the spinal cord. These are shown to be due to the resulting ischaemia of the anterior part of the lower cervical spinal cord, with degeneration of the neurones innervating the forearm and hand muscles. These findings favour external compression of the anterior spinal artery leading to ischaemia in a watershed area as the likeliest explanation for this otherwise inappropriate and bizarre phenomenon.