Electrodiagnostic abnormalities in 15 patients with posttraumatic syringomyelia: pre- and postoperative studies

Abstract

SummaryA review of 15 patients with posttraumatic syringomyelia indicates that the most reliable electrodiagnostic criteria for the diagnosis of syrinx are the loss of motor unit numbers with increase in motor unit amplitude and duration and synchronous firing. Prolongation of F wave latency in a previously stable patient is a useful observation. Return of function and improvement of F wave latencies can occur rapidly following decompression of the syrinx. Forty per cent of the patients studied had concomitant involvement of at least one peripheral nerve as one would expect invoking the double crush hypothesis.

Electrophysiological Evaluation of Root and Spinal Cord Disease

“…In syringomyelia, for example, there may be an increase in F-wave latency with a return toward normal values after surgical treatment. 35,36 The H-reflex may also be affected by traumatic or other spinal cord lesions, but the findings depend upon the timing of the examination in relation to lesion onset. In patients with spinal shock, the areflexia observed clinically is associated with an inability to elicit H-reflexes.…”