Assessment of sympathetic sudomotor function in amyotrophic lateral sclerosis with electrochemical skin conductance

• Published in: Clinical neurophysiology 2021-09, Vol.132 (9), p.2032-2036
• Main Authors: Oliveira Santos, Miguel, Castro, Isabel, Castro, José, Gromicho, Marta, de Carvalho, Mamede
• Format: Article
• Language: English
• Subjects: Amyotrophic lateral sclerosis; Autonomic nervous system; Electrochemical skin conductance; Sudomotor function; Sudoscan
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2021.05.016

•Electrochemical skin conductance is a new method to quantify sudomotor function.•ALS patients had a decreased palmar and plantar sudomotor function.•Abnormal sudomotor function is part of the ALS disease spectrum. Amyotrophic lateral sclerosis (ALS) is now recognized as a multisystem neurodegenerative disorder, comprising autonomic dysfunction. We aimed to assess sudomotor function in ALS by measuring the electrochemical skin conductance (ESC). Thirty-one ALS patients [median age of 62 years (1st-3rd interquartile range – IQR, 56–72), male 71%] were prospectively compared with 29 healthy controls, matched for age and sex. We analysed ESC results from hands and feet, bilaterally. A total of 120 ESC recordings were obtained. Hands and feet ESC measurements were significantly lower in patients compared with controls [64 μS (1st-3rd IQR, 57–58) versus 78 μS (1st-3rd IQR, 70.5–84), p  0.05). Hands and feet ESC measurements did not correlate also with disease duration, total ALSFRS-R scale, or ALSFRS-R progression rate (all p > 0.05). ESC is a non-invasive, fast and quantitative method suitable for assessing sudomotor function. ALS patients revealed a decreased function in upper and lower extremities. Sudomotor dysfunction is part of the ALS manifestations.