[Pathophysiology of detrusor underactivity in the elderly]

Aim: The aim of this study was to review the evidence regarding the pathophysiology of detrusor underactivity in the elderly.

Methods: A literature review was conducted in July 2016 using the Medline/Pubmed database limiting the search to works in English or French.

Results: The prevalence of detrusor underactivity has been reported to range from 8% to 48% depending on the definition used and the age of the population studied. Current data suggest that aging may itself be a causative factor of detrusor underactivity through myogenic dysfunctions (ultrastructural degeneration of the detrusor muscle) and neurogenic dysfunctions (by degeneration of efferent but mostly afferent innervation mechanisms). Beyond these inherently age-related mechanisms, many comorbidities whose prevalence increase with age (diabetes, bladder outlet obstruction, estrogen deficiency, atherosclerosis, etc.) may be implicated in the development of detrusor underactivity in the elderly. The role played by detrusor overactivity in the appearance of detrusor underactivity must be considered separately as both seem to be the expression of the same condition of the lower urinary tract responding to different stages and secondary to numerous etiopathogenic factors which modulate its progression and clinical expressions.

Conclusion: Pathophysiology of detrusor underactivity remains poorly understood but seems to imply myogenic and neurogenic factors which are favored, besides the aging per se, by various and numerous comorbidities which prevalence increase with age (diabetes, bladder outlet obstruction…).