Lower urinary tract function in dementia of Lewy body type

Dementia of Lewy body (DLB) type is the second commonest degenerative cause of dementia and autonomic dysfunction has been recognised in DLB. Lower urinary tract (LUT) function in DLB has not been fully delineated. We investigated LUT function in DLB by evaluating clinical and urodynamic data.

We examined 11 patients (eight men, three women; age range 65-81; disease duration 2-14 years) with probable DLB. Urodynamic studies consisted of: measurement of postvoid residual in all patients, uroflowmetry in five, and electromyography (EMG) cystometry in seven.

All patients had symptoms of LUT: urinary incontinence (urgency type/functional type due to dementia and immobility/both urgency and stress type in 7/2/1 patients, respectively); night-time frequency; urgency; and daytime frequency and voiding difficulty. Seven had postvoid residuals, and three had residual urine volume >100 ml. Decreased urinary flow was seen in all five and detrusor overactivity in 5/7 patients who underwent flowmetry and EMG cystometry, respectively. Low compliance detrusor (storage phase, n = 2; with bethanechol supersensitivity), an underactive detrusor (n = 4), an acontractile detrusor (n = 1), and detrusor-sphincter dyssynergia (voiding phase) (n = 1) were also seen; 2/3 patients who underwent motor unit potential analysis had neurogenic changes.

LUT dysfunction is a common feature in DLB, not only due to dementia and immobility, but also to central and peripheral types of somato-autonomic dysfunction.