Effects of high frequency deep brain stimulation on urine storage and voiding function in conscious minipigs

Suprapontine neural integration during the storage phase is decisive for the timing of voiding. Neurological disorders like Parkinson's disease are thus frequently complicated by bladder dysfunction. The aim of the present study was to investigate the effect of high frequency deep brain stimulation on the urine storage and voiding function in conscious Parkinsonian minipigs.

Five Goettingen minipigs had a Parkinsonism-like state induced by intoxication with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). An electrode for chronic stimulation was placed unilaterally in the subthalamic nucleus. The effect of stimulation was determined by the outcome of transurethral cystometries performed with the stimulation in on- and off-mode.

Of 20 planned cystometry-sessions 18 were completed. Six incomplete voidings occurred in stimulation on-mode and five in off-mode. Interruption of the stimulation for 2 days was followed by a significant increase in pressure rise on filling to cystometric capacity, from 7 to 21 cmH(2)O (P = 0.005), and an insignificant reduction in cystometric capacity from 30 to 26 ml/kg bodywt. (P = 0.370), leading to a significant decrease in bladder compliance from 124 to 34 ml/cmH(2)O (P = 0.013).

Transurethral cystometry was a feasible examination technique in pigs. The findings demonstrate that high frequency deep brain stimulation changes the bladder characteristics in the storage phase. Since bladder pressure and capacity responded differently to interruption of stimulation distinct neural mechanisms must be involved in the modulation of sensory information on bladder tension and stretch.