Tortuous peripheral arteries: a cause of focal neuropathy. Case report.

Segmental ulnar neuropathy has been reported as a result of ulnar nerve compression due to posttraumatic false aneurysms of the ulnar artery and, more infrequently, due to thrombosis or true aneurysms of the same vessel. The authors present a case of segmental sensory ulnar neuropathy in the wrist which intraoperatively demonstrated impingement on the ulnar nerve by a tortuous ulnar artery. The symptomatic relief and electrophysiological improvement that occurred immediately following neurovascular decompression confirm that the vascular anomaly was the cause of neuropathy. Pulsatile pressure applied to the nerve trunk may have triggered ectopic stimulation of sensory fibers manifested by a tingling and burning sensation. There was immediate resolution of paresthesia following mobilization of the impinging vessel from the nerve. Subsequent rapid electrophysiological recovery may be explained by improvement in focal nerve microcirculation following vascular decompression. Tortuosity (megadolichoectatic anomaly) of intracranial arteries has been related to cranial nerve or brain-stem dysfunction; however, this appears to be the first report in the literature of a case in which such association has been found to occur extracranially, involving a peripheral nerve.