T130. Quantitative sudomotor axon reflex testing in anterior horn cell disorders

Abstract

Autonomic disturbances in the form of hyperhidrosis, stiffness of fingers and aggravation of motor weakness on exposure to cold(Cold paresis) has been reported in anterior horn cell disorders like early stages of Amyotrophic lateral sclerosis (ALS), Brachial Monomelic Amyotrophy (BMMA) and Distal Bimelic Amyotrophy (DBMA). Quantitative sudomotor axon reflex test (QSART) was done to assess the functional integrity of postganglionic sympathetic sudomotor axons. 25 patients of BMMA, 10 patients with DBMA divided into two groups based on age (Group1: 20–30 years and Group2: 30–40 years) and 10 patients with ALS where recruited for the study and compared with equal cohort of age matched controls. General physical examination and anthropometric measurements were taken before recording. Sudomotor function of the study participants were evaluated by using Q-Sweat device manufactured by WR Medical Electronics. Resting sweat rate was recorded 5 min followed by iontophoretic stimulation. Baseline sweat volume, Total sweat volume and latency time from start of iontophoretic stimulation [acetylcholine-2 mA current strength for 5 min] to sweat response from 4 recording sites were measured. The variances in parameters like age, body weight, both height of both control and disease group were not significantly different and hence comparable. The mean age of BMMA patients: [Group1: 22.8 ± 3.8 and Group2: 33.8 ± 3.2 years] age matched controls - [Group1: 25.4 ± 2.7 and Group2: 35.1 ± 2.8 years]. There was no significant difference in baseline line sweat rate, latency and total sweat volume between controls and patients at four sites viz. Forearm, Proximal leg, Distal leg and Foot in both affected and unaffected limb. There was no significant difference between affected and unaffected limbs in above parameters in patients with BMMA. Similar results were obtained for patients in early stages of ALS (mean age 46.8 ± 3.2 years) and DBMA [Group1: 23.3 ± 4.8 and Group2: 38.0 ± 2.9 years]. Our findings suggests normal functioning of post ganglionic sudomotor fibers in BMMA and DBMA. The highly prevalent autonomic symptoms probably arise due to pre-ganglionic autonomic dysfunction and possibly in the cervical cord.