[Voiding dysfunctions in patients with lumbar spinal canal stenosis].

We studied on subjective and objective findings of 69 patients with lumbar spinal canal stenosis. Of the patients 51 (73.9%) had not only orthopedical symptoms but also urological complaints of mostly emptying disorders such as protracted and retardated dysuria and urinary retention, 14 (20.3%) no urological symptom and four (5.8%) urological complaint alone. Cystometrographic findings investigated from all of the patients revealed normoactive detrusor in 34 (49.3%) of them, underactive or acontractile detrusor in 28 (40.6%) and overactive detrusor 7 (10.1%). Eighteen of the patients underwent a surgical treatment for the lumbar spinal canal stenosis. All of seven patients with normoactive detrusor had a good micturition and four of nine with underactive or acontractile detrusor and one of two with overactive detrusor required clean intermittent catheterization (CIC) even after the surgeries. Pre and post surgical urodynamic studies demonstrated that the seven patients resulted in normoactive in four and overactive in three, the nine underactive in six and overactive in three and the two overactive and underactive in one, respectively. It was suggested from the results that the bladder of a patient with limbar spinal canal stenosis could become more irritable state after the surgery than before the therapy.

Neurogenic bladder in Hunter's syndrome.

We encountered a rare patient with Hunter's syndrome who exhibited urinary retention as a result of a neurogenic bladder, uninhibited detrusor contractions, and detrusor-sphincter dyssynergia. Neurological findings were consistent with cervical myelopathy and cervical MR imaging showed very narrow segments at the cord level C2-4. We speculate that this Hunter's syndrome patient has cervical myelopathy and that this neurological dysfunction causes the neurogenic bladder.

Excitation and inhibition of neuronal activity in the pontine micturition center by pelvic rectal and pudendal anal afferents in dogs.

To examine whether or not the pontine micturition center (PMC) is involved in the inhibition of the micturition reflex by pelvic rectal and pudendal anal afferents, neuronal activity in the PMC was observed during inhibition of this reflex in paralyzed decerebrate dogs. Discharge of pelvic vesical branches (VBs) waxed and waned at a rhythm of about 2 Hz during the micturition reflex, which was activated by continuous stimulation of the contralateral VBs. This rhythmic discharge was modulated by continuous stimulation of contralateral pelvic rectal branches (RBs) superimposed on the VB stimulation. The modulation was composed of three effects; initial inhibition, augmentation and late inhibition. However, not all of the three effects were obvious in some dogs. One-sixth of 118 neurons examined in the pontine area ventromedial to the locus ceruleus exhibited rhythmic burst firings which preceded the rhythmic discharge of VBs by about 150 ms. Therefore, these pontine neurons are assumed to be output neurons of the PMC. The rhythmic firings of pontine neurons were augmented during continuous RB stimulation independent of the inhibitory and/or augmentative effects of the RB stimulation on the reflex discharge of the VBs. In contrast, the rhythmic firings of the pontine neurons and the reflex discharge of VBs were inhibited by mechanical stimulation of the anal canal and perineal hairs. These results suggest that the PMC is involved in the inhibition of the micturition reflex produced via pudendal afferents but not in that produced by pelvic rectal afferents, and that pelvic and pudendal afferents project to the PMC through separate pathways.

[Effects of afferent vagal stimulation and distention of the upper digestive tract on the micturition reflex and activity of the pontine micturition center in dogs].

(1) The study was performed to elucidate the effects of afferent vagal stimulation and distension of the digestive tract on the micturition reflex in 21 acute decerebrate dogs immobilized with gallamine. Electrical stimulation of the central cut end of the cervical vagus nerve with high voltage (17.5-25 V) and moderate frequency (10-50 Hz) elicited in most cases inhibition of the periodic bladder contractions and of outflows of the pelvic vesical branch which were induced by a sustained intravesical pressure of 10-15 cmH2O. Distension of the thoracic esophagus, the stomach, and the duodenum also induced inhibition of the bladder contractions and of the pelvic outflow to the bladder. Such inhibitions were abolished after bilateral cervical vagotomies except a few cases of distension of the duodenum. (2) Another series of experiments were undertaken to clear the effect of afferent vagal stimulation on the electrical activity of the pontine micturition center in 10 acute decerebrate dogs. By means of an extracellular glass microelectrode method, unitary discharges synchronized with the grouping discharges in the pelvic vesical branch with a rhythm of 2.2-2.5 Hz were recorded from the pontine micturition center in the dorsolateral pontine tegmentum. Such a type of discharges was detected in 6 of 59 units which discharged by afferent stimulation of the pelvic vesical branch. This type of discharges was inhibited by afferent vagal stimulation at the supradiaphragmatic level. From these results, it may be concluded that the afferent pathway of the bladder relaxation reflex induced by distension of the upper digestive tract is mainly involved in the vagal nerves, but in some cases of the strong distension of the duodenum, the pathway is in splanchnic nerves, and that inhibition of the bladder contraction after stimulation of vagal nerve is induced by suppression of the pontine micturition centers.