Autonomic system and amyotrophic lateral sclerosis

Abstract

Introduction: The aim of this study is to characterize autonomic impairment in motor neuron disease.

Methods: Neurological evaluations and autonomic testing were analyzed retrospectively in 132 patients: 86 classic amyotrophic lateral sclerosis (ALS), 36 lower motor neuron (LMN), and 10 upper motor neuron (UMN) predominant disease.

Results: One-third of patients were symptomatic; urinary urgency and constipation were the most frequent symptoms. Increased Composite Autonomic Severity Score (CASS) was present in 75% with mild impairment (CASS 1-3) in 85% and moderate (CASS 4-7) in 15%. The frequencies of testing abnormalities were: sudomotor 46%, cardiovagal 50%, and adrenergic 14%. The UMN group had significantly higher median CASS scores than the classic ALS (P = 0.021) and LMN group (P = 0.018).

Conclusions: We found predominantly mild autonomic impairment in ALS patients, with mostly cardiovagal and sudomotor involvement. Moderate autonomic failure occurred in 1 of 7 patients, especially those with an UMN presentation. Patients with selective corticospinal tract involvement may have more impairment of autonomic pathways.

Keywords: Composite Autonomic Severity Score; amyotrophic lateral sclerosis; autonomic impairment; motor neuron disease; sudomotor.

© 2014 Wiley Periodicals, Inc.

Figures

Figure 1

Comparison of median total CASS scores among the 3 groups of motor neuron disease. The bars represent the 5/95th percentiles. Note significantly higher scores in the upper motor neuron group (Median: 3.5, SD: 1.75, SEM: 0.55) when compared to classic ALS (Median:1.0, SD:1.27, SEM: 0.13) and lower motor neuron (Median: 1.0, SD: 1.33, SEM: 0.22) predominant groups. There was no significant difference between the LMN and classic ALS groups. SD: standard deviation. SEM: standard error of the mean.

Figure 2

Comparison of the CASS sudomotor component among the 3 motor neuron disease groups. The bars represent the 5/95th percentiles. Note significantly greater sudomotor impairment in the UMN group compared to the LMN group and classic ALS vs LMN group. The comparison of classic VS UMN was not significant.