**4.2.2 Stress incontinence**

Stress incontinence: this is most common in frail elderly women and uncommon in men, except when the external urethral sphincter has been damaged during prostatic surgery. The causes are generally related to pelvic floor weakness which produces a urethral hypermobility (multiparity, hypoestrogenism, obesity) or previous pelvic surgery (gynaecological, prostatic resection). The urine leakages will be produced with manoeuvres that cause an increase in intra-abdominal pressure (coughing, laughing, sneezing, Valsalva). Usually the length of the symptoms is long, and the impact on quality of life is lower than urge incontinence.

### **4.2.3 Overflow incontinence**

Overflow incontinence: this appears in situations of bladder overdistension. There are two different mechanisms: bladder outlet obstruction (prostatic hyperplasia, urethral stenosis, faecal impaction) and bladder contractile impairment (spinal cord lesions, peripheral and/or autonomic neuropathy, detrusor myopathy, anticholinergic drugs). Within this subgroup of incontinence, a relatively common entity exists, especially in disabled patients, called Detrusor Hyperactivity with Impaired Contractility (DHIC). This term was coined by Resnick in 1987 when he observed a characteristic urodynamic pattern, in an incontinent and disabled elderly group, of uninhibited bladder contractions together with an inability to empty more than 50% of the bladder content (Resnick, 1996). Nowadays, DHIC is considered a subtype of bladder hyperreflexia, but the mechanism that produces bladder contractile impairment is unknown. It is proposed that it may be an evolved phase of bladder hyperreflexia, with the production of muscle failure (Smith PP, 2010). From the clinical point of view, patients may present with both irritative type urinary symptoms (urge, frequency), as well as obstructive type (incomplete voiding, urinary retention). Characteristically, post-voiding residual urine volumes are pathological. Although DHIC generally presents with urge incontinence, it may also manifest with symptoms of obstruction, stress or overflow incontinence. This form of bladder hyperactivity is the second commonest cause of incontinence in institutionalized patients. An episode of urinary retention may occur when some other factor (drugs, immobility, and fecal impaction) further alters bladder contractility (Verdejo, 2004).
