Sensory abnormalities and entrapment neuropathies identified by nerve conduction studies in patients with amyotrophic lateral sclerosis

Abstract

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder primarily affecting motor neurons; however, non-motor symptoms, including sensory and autonomic disturbances, are increasingly recognized. This retrospective cross-sectional study evaluated the frequency of sensory and entrapment neuropathies in 114 patients with ALS using electrodiagnostic (EDX) studies. Demographic characteristics, comorbidities, and sensory and autonomic symptoms were documented. Electrophysiological evidence of sensory neuropathy was identified in 20 patients overall (20/114, 17.5%), including 10 patients without diabetes mellitus (DM), whereas entrapment neuropathy was detected in 28 patients overall (28/114, 24.6%), including 16 of those without DM or hypothyroidism. Sensory neuropathy was significantly associated with both DM and a history of chronic disease. In contrast, these comorbid conditions were not significantly associated with entrapment neuropathy. Furthermore, patient-reported symptoms showed no correlation with electrophysiological evidence of sensory involvement on EDX. Sensory neuropathy was more frequent in patients with spinal-onset than bulbar-onset disease, although the difference was not statistically significant. This study confirms that sensory involvement is not uncommon in ALS. Although clinical symptoms are poor predictors, electrophysiological abnormalities consistent with sensory and entrapment neuropathies are common. A significant proportion of these abnormalities are idiopathic and may directly reflect the disease process itself, particularly in spinal-onset cases.