Sönke Boy

Brain activation in response to bladder filling and simultaneous stimulation of the dorsal clitoral nerve—An fMRI study in healthy women

AIMS Using functional magnetic resonance imaging (fMRI) we investigated the cortical and subcortical representations during bladder filling and the effect of simultaneous stimulation of the dorsal clitoral nerve on these cortical and subcortical structures. METHODS After approval of the local ethics committee, 8 healthy females were included. Prior to scanning, subjects were catheterized and the bladder was filled until first desire to void occurred. In a block design protocol we performed repetitive manual bladder filling (FILLING) and emptying of additional 80 ml saline, alternating with rest conditions (REST) of constant bladder volume. The protocol was repeated with simultaneous stimulation of the dorsal clitoral nerve during the filling periods (COMBINED). Activation maps were calculated by means for 3 different contrasts: 1) FILLING>REST, 2) COMBINED>REST and 3) FILLING>COMBINED. RESULTS A group analysis of contrast 1) showed activation of the right prefrontal and orbitofrontal cortices, the insula bilaterally, the left precuneus, the parietal operculum bilaterally, the cerebellum bilaterally (q(FDR)< or =0.001), the right anterior cingulate gyrus (q(FDR)< or =0.005) and the right anterior mid pons (q(FDR)< or =0.05). Contrast 2) showed activation in the right frontal area, the left insula, the parietal operculum bilaterally and the left cerebellum (q(FDR)< or =0.001). Deactivations were found in the middle frontal gyrus bilaterally and the post- and paracentral gyri bilaterally. Contrast 3) revealed stronger activation during FILLING in the bilateral frontal and prefrontal areas, the right anterior cingulated gyrus, and the right putamen (q(FDR)< or =0.05). Only the right insula showed stronger activation during the COMBINED condition. CONCLUSION Simultaneous dorsal clitoral nerve stimulation during bladder filling reduced the activation of certain cortical areas suggesting a neuromodulatory effect of this stimulation on supraspinal centres involved in lower urinary tract control.

The effects of tolterodine on bladder-filling sensations and perception thresholds to intravesical electrical stimulation : method and initial results

To study the effects of the antimuscarinic agent tolterodine on the perception thresholds to intravesical electrical stimulation (IES) and the effects of the drug on subjective bladder sensation during normal filling cystometry in healthy female volunteers.

The facilitatory effect of duloxetine combined with pelvic floor muscle training on the excitability of urethral sphincter motor neurons.

Introduction and hypothesisAim of this study was to investigate the excitability of sphincter motor neurons under the influence of pelvic floor muscle training (PFMT) and duloxetine. Due to their mechanisms of action, there might be a synergistic effect of duloxetine and PFMT in regard to the facilitation of spinal reflexes controlling urethral sphincter contractions and hence continence.MethodsIn ten healthy female subjects, clitoral electric stimulation (CES) and transcranial magnetic stimulation (TMS) were used to determine individual motor thresholds for external urethral sphincter (EUS) contractions before and after PFMT, duloxetine, and PFMT + duloxetine.ResultsPFMT and duloxetine alone significantly decreased the motor thresholds for EUS contractions during CES and TMS. However, the combined treatment reduced the motor threshold for EUS contractions significantly stronger compared to PFMT or duloxetine alone.ConclusionsThe results are suggestive for a synergistic facilitatory effect of PFMT and duloxetine on sphincter motor neuron activation.

A case of undiagnosed tethered cord syndrome aggravated by transurethral prostate resection.

Background A 68-year-old man presented with a history of significant urinary urge incontinence, pollakiuria, and weak bladder sensation. He also reported mild fecal incontinence and a hypotrophic and slightly weaker left leg. At 63 years of age he had presented to a urologist for treatment of irritative lower urinary tract symptoms and incontinence. A transurethral resection of the prostate had been performed. After the operation, the symptoms had persisted and the incontinence seriously worsened.Investigations Clinical neurologic examination, videourodynamic examination, neurophysiologic examination, and MRI of the spinal cord.Diagnosis Neurogenic bladder dysfunction caused by adult tethered cord syndrome with myelon up to S2 level, spina bifida occulta, and lipoma infiltrating the conus medullaris.Management Conservative anticholinergic treatment failed, and injection of botulinum-A toxin is planned.