A. L. Dalmose

A portable device for experimental treatment of neurogenic detrusor overactivity.

The objective of this study was to evaluate the effect of automatic event‐driven electrical stimulation on the dorsal penile/clitoral nerve for management of neurogenic detrusor overactivity in spinal cord injured subjects. In order to reach the objectives it was necessary to design and realize a portable device for ambulatory urodynamic studies which was able to activate an electrical stimulator when the detrusor pressure exceeded a certain threshold. The developed device was repeatedly tested in a healthy subject and subsequently tested in a spinal cord injured subject. In testing the automatic event‐driven system in the spinal cord injured subject, detrusor contractions were successfully inhibited until a certain bladder volume was reached and no incontinence episodes were observed prior to disabling the system. The preliminary results indicate that automatic event‐driven electrical stimulation on the dorsal penile/clitoral nerve can inhibit involuntary detrusor contractions in spinal cord injured subjects and hereby restore continence and increase bladder capacity.

Stereotactic electrical stimulation of the pontine micturition centre in the pig

To apply stereotactic electrical stimulation of the pig brainstem and thus identify a pontine micturition centre.

Bladder and Urethral Responses to Pelvic Nerve Stimulation in the Pig

Objective: The aim of our study of the pig was to investigate the responses of smooth muscle of the bladder and the urethral sphincter to preganglionic parasympathetic stimulation, and to assess the effect on the lower urinary tract of IV administration of f , g -methylene-ATP. Materials and methods: In seven anaesthetised female pigs, the responses to repeated 20 s pelvic nerve stimulations before and after IV administration of 0.02 mg/kg f - g -methylene-ATP, and the responses to the drug itself, were recorded in the bladder and the urethra separately. Results: In the urethral high-pressure zone, pre-stimulation pressure was a mean of 61 - 11 cmH 2 O. During pelvic nerve stimulation, urethral pressure declined by 48 - 9 cmH 2 O, while the bladder pressure increased to 30 - 18 cmH 2 O. The rate of pressure changes during the first 3 s of stimulation (initiation of voiding) was larger in the urethra than in the bladder (urethral pressure decrease: 13.0 - 3.1 cmH 2 O/s, bladder pressure increase: 3.2 - 2.5 cmH 2 O/s). Administration of f , g -methylene-ATP was followed by a significant but temporary enlargement in the bladder response to pelvic nerve stimulation to 36 - 20 cmH 2 O, p = 0.028, n = 7, but no change in urethral response. Conclusions: At least 80% of the urethral pre-stimulation pressure was exerted by the smooth muscle. The synergic activation of the detrusor and the urethral smooth muscle in response to preganglionic parasympathetic nerve stimulation was controlled by the peripheral nerves or by the neuromuscular transmission. Administration of f , g -methylene-ATP increased the bladder response to pelvic nerve stimulation without changing the urethral response.