Toward in vivo determination of peripheral nervous system immune activity in amyotrophic lateral sclerosis.

Introduction: We sought to identify patients with amyotrophic lateral sclerosis (ALS) who displayed suspected peripheral nervous system (PNS) inflammation to compare them to those with suspected PNS degeneration.
Methods: We measured sonographic median and ulnar nerve cross-sectional area (CSA) and cerebrospinal fluid albumin/serum albumin ratio (Q _alb ) in patients with ALS to classify them as having suspected PNS degeneration (small CSA/low Q _alb ) or inflammation (larger CSA/high Q _alb ).
Results: Fifty-seven percent of patients had suspected PNS degeneration, 21% had suspected PNS inflammation, and 21% displayed suspected "normal PNS state." Suspected PNS degeneration was related to classic ALS, shorter disease duration, and a smaller hypoechoic nerve area. Suspected PNS inflammation was associated with men, longer disease duration, and a larger hypoechoic nerve area and was the dominant finding in superoxide dismutase 1 mutation carriers.
Discussion: Our simple approach might aid in the in vivo differentiation of supposed ALS subtypes, those with suspected PNS degeneration vs. inflammation, for stratification in clinical trials. Muscle Nerve 59:567-567, 2019.
(© 2019 Wiley Periodicals, Inc.)