Albert Borau

Urethral Sphincter EMG as Event Detector for Neurogenic Detrusor Overactivity

The aim of this study was to investigate the feasibility of using external urethral sphincter electromyogram (EMG) (EUSEMG) to detect the onset of detrusor contractions in patients with both neurogenic detrusor overactivity (NDO) and detrusor sphincter dyssynergia (DSD). Detrusor pressure (Pdet) and EUSEMG was recorded in 23 neurogenic patients during slow artificial bladder filling. The time delay between the onset of EUSEMG detrusor contraction and the onset of activity was calculated together with the detrusor pressure increase related to this delay. Of 23 patients enrolled, 12 patients showed both NDO and DSD. Of these 12 patients, 10 had a strong correlation between detrusor pressure and EUSEMG . One patient in this group was excluded due to a storage pressure above 30 cmH2O . Two detection methods were applied on the remaining 9 patients. Method 1 was a root mean square (RMS)-integrator with simple thresholding. This approach had a good sensitivity but also a poor specificity (many false-positive detections). Detection method 2 included a kurtosis-based scaling function, which was multiplied to a similar RMS-integrator as used in method 1. Onset detection occurred before Pdet exceeded 18 cmH2O with both methods. However, method 1 resulted in 14.1plusmn12.8 false-positive detections during one bladder filling.Pdet at onset detection was on average 1.0plusmn1.1 cmH2O higher with detection method 2 but the number of false-positives was reduced by 95.8%. This paper demonstrates the feasibility of using EUSEMG to estimate the onset of a detrusor contraction in selected patients.

Effect of sacral anterior root stimulator on bowel dysfunction in patients with spinal cord injury.

PURPOSE: Bowel dysfunction is a problem in patients with spinal cord injury. The sacral anterior root stimulator has been used for neurogenic bladder and has been claimed to be useful for neurogenic bowel. The purposes of this study were to analyze the clinical response of bowel function to the sacral anterior root stimulator and to evaluate physiologic factors that could determine its efficacy. METHODS: Eighteen consecutive patients with spinal cord injury and an implanted sacral anterior root stimulator were evaluated. Clinical assessment, colonic transit time, and anorectal manometry were performed. Patients were evaluated before implantation of the sacral anterior root stimulator and clinically reevaluated after 12 months. RESULTS: Fewer patients required laxatives after implantation of the sacral anterior root stimulator. The mean number of methods used to evacuate was reduced from 2.1 to 1.5 (P < 0.05). Bowel movement frequency was higher (P < 0.05). Time devoted to defecation was reduced, although no statistical significance was achieved. Fecal incontinence did not change, but constipation was reduced (P < 0.05). Most patients reported being more satisfied with bowel function after implantation of the sacral anterior root stimulator. No correlation was found between objective and subjective responses to the sacral anterior root stimulator and manometric or colonic transit times before implantation. CONCLUSION: The sacral anterior root stimulator improves bowel function, and patient satisfaction with this treatment is high. Further studies are needed to evaluate the characteristics of stimulation parameters to achieve better results.

Subject‐controlled stimulation of dorsal genital nerve to treat neurogenic detrusor overactivity at home

To investigate the effects of subject controlled dorsal genital nerve (DGN) electrical stimulation on neurogenic detrusor overactivity (NDO) in subjects at home.

Urethral sphincter EMG-controlled dorsal penile/clitoral nerve stimulation to treat neurogenic detrusor overactivity.

The goal of this study was to investigate whether real-time external urethral sphincter (EUS) EMG-controlled dorsal genital nerve (DGN) stimulation can suppress undesired detrusor bladder contractions in patients with both neurogenic detrusor overactivity (NDO) and detrusor sphincter dyssynergia (DSD). Detrusor pressure (Pdet) and EUS EMG were recorded in 12 neurogenic patients who underwent two filling cystometries. The first one was without stimulation and was intended to confirm the NDO and DSD and to set the EMG detection threshold. The second one was with real-time EMG-controlled stimulation of DGNs. Two detection methods were analyzed to detect bladder contractions. The first method was a Kurtosis-scaled root mean square (RMS) detector and was used on-line. The second was a simple RMS detector and was used off-line. Of 12 patients included, 10 patients showed both NDO and DSD. In nine of these ten patients relevant EMG concomitant to detrusor activity was detected and stimulation could suppress at least one detrusor contraction. The second filling compared to the first one showed an increase of 84% in bladder capacity (p = 0.002) and a decrease of 106% in Pdet (p = 0.002). Nine false-positive detections occurred during the ten fillings with electrical stimulation. The mean increases of both time and Pdet between stimulation and bladder contraction onsets for method 1 were 1.8 s and 4 cmH(2)O and for method 2 were 0.9 s and 2 cmH(2)O, respectively. This study shows that EUS EMG can be used in real time to detect the onset of a bladder contraction. In combination with DGN stimulation has been shown to be feasible to suppress undesired bladder contractions and in turn to increase bladder capacity in subjects with both NDO and DSD.

Surgical management of the neurogenic bladder after spinal cord injury

PurposeThis work represents the efforts of the SIU-ICUD workgroup on this topic and comprehensive literature search of English language manuscripts regarding urologic surgery in spinal cord injury using key words of urologic surgery and spinal cord injury. Articles were compiled, and recommendations in the chapter are based on group discussion and intensive communication. The purpose is to review what has been published during the last decades on urological surgery for neurogenic bladder after spinal cord injury.MethodsSurgical techniques applied in spinal cord injured patients for neurogenic bladder dysfunction have been reviewed and the published material evaluated.ResultsThere are several techniques that can be used to treat neurogenic dysfunctions and symptoms in refractory cases where conservative treatment failed. The number of publications is small as are the number of patients with spinal cord injury in which they have been performed. The choice of techniques proposed to the patients depends on the exact functional pathology in bladder, bladder neck and urethral sphincter. The final informed choice will be made by the patient.ConclusionThere are surgical urological techniques available to treat neurologic dysfunctions in spinal cord injured patients.

Intraoperative recording of ENG from human sacral nerve roots

Intraoperative recoding of electroneurograms (ENG) from the S3 extradural sacral nerve roots was performed in 2 SCI patients. The goal of this work was to study the relation between mechanical stimulation of the urinary bladder, rectum and skin and the resulting ENC-signals. These signals could be used to detect the onset of a bladder contraction. This concept could be used in an implantable neuroprostheses to treat detrusor hyperreflexia. The recorded human signals are consistent with data from animal studies. However, more human studies are needed.