Purpose： Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorders involving both upper and lower motor neurons. Patients with ALS would inevitably lose all somatic nerve function, but autonomic nerve function is relatively preserved. Clinically we observed that these patients might have variable lower urinary tract symptoms, which hasn’t been reported in the medical literature. Therefore, we conducted a retrospective observational study to investigate the prevalence of urinary symptoms in one of the largest ALS referral centers in Taiwan.

Materials and Methods： We retrospectively reviewed patients with ALS in our institute from January 1^st 2014 to March 15^th 2016. Those with urinary symptoms that needed referral to a urologist were included. Age, sex, comorbidities, initial presentation and duration of ALS, muscle power of lower extremities, and urinalysis at the time of referral were obtained from chart review or telephone interview. These data were analyzed with descriptive statistics. Fisher’s exact test was used to compare possible associated factors between ALS patients with urinary retention and those without. P value less than 0.05 was viewed as statistical significance.

Results： Sixteen patients have been included, accounting for 12.4% of all ALS patients in our institute during the study period. Twelve were males (75%) and four were females (25%).  Median age at referral was 61 (39 – 79) years of age. Median duration of ALS was 5 (0.5 – 29) years. Three (18.8%) patients had type 2 diabetes, and 15 (93.8%) patients needed respiratory support. Five (41.7%) patients presented initially with dysarthria, while seven (58.3%) patients were diagnosed with ALS due to weakness of extremities. Ten (62.5%) patients preserved some degree of muscle power at the time of urological referral (Table 1). Refractory lower urinary tract symptoms were the chief complaints, including voiding symptom predominance in six (37.5%), storage symptom predominance in four (25.0%), and dysuria in six patients (37.5%). Pyuria was only presented in two patients with dysuria. Nine patients were diagnosed with urinary retention after evaluation by urologists. Median postvoid residual urine amount was 820 (550 – 2100) ml. Factors including age, sex, disease duration, residual muscle power, or initial presentations were failed to show association with the development of urinary retention in patients with ALS. (Table 2)   

Conclusions： Urinary symptoms, including voiding and storage symptoms, as well as dysuria were not rare in patients with ALS. Urinary retention was the most common urological conditions, but associated factors were failed to be identified in the present study. A prospective study recruiting more patients with ALS would be helpful to predict the development of urinary retention in this patient population.

 

Table 1 Demographic data of ALS patients who needed referral to a urologist

 

Table 2. Associated factors of urinary retention in patients with ALS.