Tendon‐reflex testing in chronic demyelinating polyneuropathy

We studied the tendon reflex (T‐reflex) in 26 patients with acquired chronic demyelinating polyneuropathy (CDN), including 22 with chronic inflammatory demyelinating polyneuropathy (ClDP). In 7 patients reflexes were brisk or normal on clinical testing. The height adjusted T‐reflex was abnormal in 25 (96%) cases, including 6 of 7 patients with brisk or normal reflexes on clinical testing. Mean latency ( P < 0.01) and duration ( P < 0.05) of the ankle and patellar tendon reflexes were significantly prolonged in the ClDP patients when compared to the controls. Mean latency in the ClDP patients was 152% of normal means. In 7 CIDP patients, the T‐reflex latencies were prolonged beyond 150% of normal means. Thus, the T‐reflex test is abnormal in a majority of patients with CDN, even in the presence of well‐preserved clinical reflexes, and the T‐reflex latency is a useful indicator of the presence of a demyelinating peripheral neuropathy in some patients. © 1994 John Wiley & Sons, Inc.