Urinary symptoms in patients with amyotrophic lateral sclerosis

Dear Editor:

It was with great interest that we read the article by Martínez et al.¹ on the frequency of non-motor symptoms in patients with amyotrophic lateral sclerosis (ALS). The relatively high incidence of these symptoms is becoming increasingly apparent, and has considerable implications for prognosis and treatment.² However, the authors report a surprisingly low incidence of “urinary problems” (2%). It is unclear what type of urinary problems the authors are referring to, but a previous study by our research group³ found lower urinary tract symptoms (evaluated with standardised questionnaires) in 43.6% of a series of patients with ALS, with 26.3% of patients presenting urgency urinary incontinence; these incidence rates are similar to those reported in other studies.^4,5 In most patients, symptoms affected both bladder filling and voiding, and were attributable to detrusor sphincter dyssynergia.³ In fact, our results showed that although urinary symptoms were slightly more frequent in men, incidence was not influenced by age or such clinical characteristics as the subtype of motor neuron disease.⁶ Furthermore, an association was found between presence of urinary symptoms and poorer prognosis.⁶ Our findings contradict the idea, widespread among both patients and healthcare professionals, that urinary symptoms are rare in ALS and secondary to loss of mobility.⁷ Screening for filling and voiding symptoms and urinary incontinence with validated questionnaires is essential in patients with ALS due to the negative impact that these potentially treatable problems may have on patient quality of life.³

Funding

JFVC has received funding from Institute of Health Carlos III (Río Hortega research grant no. PI 17/00137).

Conflicts of interest

None.