Nonmotor Symptoms in Amyotrophic Lateral Sclerosis: A Systematic Review

ALS is a progressive neurodegenerative disease with no curative treatment. Nonmotor symptoms presenting in ALS may cause significant distress, worsen prognosis, and affect survival.To systematically review evidence for the prevalence of nonmotor ALS symptoms, and treatment options.Multiple medical literature databases were searched and studies screened using predefined inclusion criteria. Of 4580 studies, 44 were eligible for inclusion with 25 relating to treatment and 19 to the prevalence of nonmotor symptoms in ALS.Nonmotor symptoms involve neuropsychiatric, autonomic, gastrointestinal, and vascular systems, and affect between 5% and 80% of people with ALS. Screening tools for individual nonmotor symptoms are useful in classifying symptom severity and to compare between treatment options. Several methods to relieve nonmotor symptoms have been trialed with varying success rates.Many of the current studies of nonmotor symptoms in ALS have small sample sizes, requiring more evidence to increase precision in prevalence estimates. Further research is needed to assess the efficacy of current treatments and to find new therapies. Symptom relief or treatment of these nonmotor symptoms should therefore be considered during the clinical management of ALS.