Characterization of lower urinary tract dysfunction in a mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is characterized by a progressive loss of motor function due to degeneration of motor neurons. In addition to motor-related symptoms, increasing evidence from clinical studies indicate lower urinary tract (LUT) dysfunctions (urge incontinence) are found in patients with ALS, which causes a significant negative impact on quality of life. However, it remains unclear whether LUT dysfunction can be validated in preclinical ALS models. Here, we attempt to answer this question by using comprehensive urodynamic testing with electromyogram of external urethral sphincter (EUS) activity in both female and male SOD1-G93A ALS mice at both 9 weeks of age (pre-onset stage) and 16 weeks of age (early symptomatic stage). Our results demonstrate that the detrusor muscle is hyperactive, voiding volume is decreased, and the EUS relaxation period is shorter in female and male SOD1-G93A ALS mice at both 9 weeks and 16 weeks of age, compared to age-matched wild-type animals. The symptoms of urge incontinence found in the current study are similar to the clinical findings, indicating that SOD1-G93A ALS mice can be used as a preclinical model to develop therapeutics for ALS patients with LUT dysfunction.