Transurethral versus suprapubic catheterization to test urethral function in rats

Transurethral and suprapubic catheterization have both been used to test urethral function in rats; however, it is unknown whether these methods affect urethral function or if the order of catheterization affects the results. The aim of this cross-over designed experiment was to compare the effects of catheterization methods and order on leak point pressure (LPP) testing. LPP and simultaneous external urethral sphincter electromyography (EUS EMG) were recorded in anesthetized female virgin Sprague-Dawley rats in a cross-over design to test the effects of transurethral and suprapubic catheterization. There was no significant difference in peak bladder pressure during LPP testing whether measured with a transurethral or suprapubic catheter. There was no significant difference in peak bladder pressure between the first and second catheter insertions. However, peak EMG firing rate, as well as peak EMG amplitude and EMG amplitude difference between peak and baseline were significantly higher after the first catheter insertion compared to the second insertion, regardless of the catheter method. Our results suggest that route of catheterization does not alter urethral function, e.g. create a functional partial outlet obstruction. Either catheterization method could be used for LPP and/or EUS EMG testing in rats.

Bladder and bowel responses to lumbosacral epidural stimulation in uninjured and transected anesthetized rats

Spinal cord epidural stimulation (scES) mapping at L5-S1 was performed to identify parameters for bladder and bowel inhibition and/or contraction. Using spinally intact and chronic transected rats of both sexes in acute urethane-anesthetized terminal preparations, scES was systematically applied using a modified Specify 5–6–5 (Medtronic) electrode during bladder filling/emptying cycles while recording bladder and colorectal pressures and external urethral and anal sphincter electromyography activity. The results indicate frequency-dependent effects on void volume, micturition, bowel peristalsis, and sphincter activity just above visualized movement threshold intensities that differed depending upon neurological intactness, with some sex-dependent differences. Thereafter, a custom-designed miniature 15-electrode array designed for greater selectivity was tested and exhibited the same frequency-dependent urinary effects over a much smaller surface area without any concurrent movements. Thus, select activation of autonomic nervous system circuitries with scES is a promising neuromodulation approach for expedient translation to individuals with SCI and potentially other neurologic disorders.

Possible “Premotor” Multiple System Atrophy-Cerebellar Form

We report the case of a 52-year-old Japanese man who, while he had no cerebellar ataxia or parkinsonism, was revealed to have silent cerebellar hypoperfusion/mild cerebellar atrophy and sacral autonomic disorder. His sacral autonomic disorder was urinary retention without marked prostate hyperplasia. Urodynamics-sphincter electromyography revealed detrusor hyperactivity with impaired contraction and neurogenic changes of the sphincter motor unit potentials. Although he did not have a motor disorder, these features suggested possible multiple system atrophy-cerebellar (MSA-C) form. The present case report suggests that neuroimaging helps in diagnosing “premotor” MSA-C form in situ.

Early presentation of urinary retention in multiple system atrophy: can the disease begin in the sacral spinal cord?

Lower urinary tract (LUT) dysfunction presents early in multiple system atrophy (MSA), usually initially as urinary urgency, frequency and incontinence, and voiding difficulties/urinary retention becomes apparent over time. We have observed a subset of patients who instead presented initially with urinary retention requiring catheterisation. At presentation, these patients had only subtle neurological signs that would not fulfil the diagnostic criteria of MSA; however, the anal sphincter electromyography (EMG) was abnormal and they reported bowel and sexual dysfunction, suggesting localisation at the level of the sacral spinal cord. They subsequently developed classical neurological signs, meeting the diagnostic criteria for probable MSA. One patient was confirmed to have MSA at autopsy. We postulate that in a subset of patients with MSA, the disease begins in the sacral spinal cord and then spreads to other regions resulting in the classical signs of MSA. The transmissibility of alpha-synuclein has been demonstrated in animal models and the spread of pathology from sacral cord to other regions of the central nervous system is therefore plausible. Patients presenting with urinary retention and mild neurological features would be an ideal group for experimental trials evaluating neuroprotection in MSA