Abstract:

Objective To evaluate the functional status of the sensory system in patients with amyotrophic lateral sclerosis (ALS) by neuroelectrophysiological techniques. Methods According to the revised El Escorial diagnostic criteria, 66 patients with clinically confirmed and proposed limb-onset ALS were included and divided into the sensory symptom (sALS, n=13) group and without sensory symptom (nsALS, n=53) group according to the presence or absence of clinical sensory symptoms. Sixty healthy individuals were selected as the health control (HC) group. Sensory nerve conduction studies (SNCS) and skin sympathetic response (SSR) of bilateral upper and lower limbs were detected by Keypoint 4 electromyography evoked potential instrument. Pathway pain and sensation assessment system was used to conduct contact heat evoked potential (CHEP) detection of bilateral anterolateral leg and forearm volar side. Results (1) The abnormal rates of SNCS, SSR and CHEP in the ALS group were 0%, 21.2% (14/66) and 27.3% (18/66), respectively. The abnormal rates of SSR and CHEP in the sALS group were 30.8% (4/13) and 38.5% (5/13). The abnormal rates of SSR and CHEP in the nsALS group were 18.9% (10/53) and 24.5% (13/53). (2) Compared with the HC group, the latency of SSR in lower limbs was prolonged in the sALS group and the nsALS group, the latency of N wave in CHEP of upper and lower limbs was prolonged, and the amplitude of N-P wave was decreased (P<0.05). Compared with the nsALS group, the sALS group showed prolonged N wave latency and reduced N-P wave amplitude for anterolateral calf stimulation by CHEP detection (P<0.05). Conclusion ALS patients have small fiber damage in the sensory system.

Key words: amyotrophic lateral sclerosis, contact heat evoked potential, skin sympathetic response, sensory nerve conduction