Electrical stimulation of the urethra evokes bladder contractions and emptying in spinal cord injury men: case studies

OBJECTIVE

Electrical stimulation of the urethra can evoke bladder contractions in persons with spinal cord injury (SCI). The objective of this study was to determine whether electrical stimulation of the urethra could evoke bladder contractions that empty the bladder.

METHODS

The first patient was a 45-year-old man with a T6 ASIA A SCI secondary to a gunshot wound 15 years prior. The second patient was a 51-year-old man with a T2 ASIA A SCI secondary to a fall from scaffolding 2 years prior. Both patients demonstrated neurogenic detrusor overactivity on urodynamics and managed their bladder with clean intermittent catheterization and oxybutynin medication. Following informed consent, each patient discontinued oxybutynin 2 days prior to urodynamic testing. Urodynamics were performed with a custom 12 French balloon catheter mounted with ring-shaped electrodes (3 mm) positioned in the prostatic urethra. After filling the bladder to approximately three-fourth of capacity at a rate of 25 ml/minute, the urethra was stimulated with a range of parameters to determine whether electrical stimulation could evoke a bladder contraction and empty the bladder.

RESULTS

Electrical stimulation of the prostatic urethra evoked bladder contractions (peak detrusor pressures of 60-80 cm H(2)O) that emptied the bladder in both subjects. In the first subject, stimulation (9-12 mA, 20 Hz) emptied 64-75%, leaving post-void residual volumes (PVRs) of 41-20 ml. In the second subject, stimulation (20 mA, 20 Hz) emptied 68-77%, leaving PVRs of 56-45 ml.

CONCLUSION

Urethral stimulation evoked bladder emptying in persons with SCI.

Electrical stimulation of the urethra evokes bladder contractions in a woman with spinal cord injury

OBJECTIVE

Electrical stimulation of pudendal urethral afferents generates coordinated micturition in animals and bladder contractions in men after spinal cord injury (SCI), but there is no evidence of an analogous excitatory urethra-spinal-bladder reflex in women. The objective of this study was to determine whether electrical stimulation of the urethra could evoke bladder contractions in a woman with SCI.

CASE REPORT

A 38-year-old woman with a C6 ASIA A SCI who managed her bladder with clean intermittent catheterization and oxybutynin demonstrated neurogenic detrusor overactivity on urodynamics. Oxybutynin was discontinued 2 days prior to urodynamic testing with a custom 12F balloon catheter mounted with ring-shaped electrodes located in the bladder neck, mid urethra, and distal urethra. The inflated balloon was placed against the bladder neck to stabilize the catheter electrodes in place along the urethra. However, the balloon limited emptying during contractions. Urodynamics were performed at a filling rate of 25 mL/minute until a distention-evoked bladder contraction was observed. The urethra was stimulated over a range of bladder volumes and stimulus parameters to determine whether electrical stimulation could evoke a bladder contraction.

FINDINGS

Electrical stimulation via urethral electrodes evoked bladder contractions that were dependent on bladder volume (>70% capacity) and the intensity of stimulation.

CONCLUSIONS

This is the first report of an excitatory urethra-spinal-bladder reflex in a woman with SCI. Future studies will determine whether this reflex can produce bladder emptying.

Intramuscular Electrical Stimulation for Hemiplegic Shoulder Pain

OBJECTIVE

Assess the effectiveness of intramuscular electrical stimulation in reducing hemiplegic shoulder pain at 12 mos posttreatment.

DESIGN

A total of 61 chronic stroke survivors with shoulder pain and subluxation participated in this multiple-center, single-blinded, randomized clinical trial. Treatment subjects received intramuscular electrical stimulation to the supraspinatus, posterior deltoid, middle deltoid, and upper trapezius for 6 hrs/day for 6 wks. Control subjects were treated with a cuff-type sling for 6 wks. Brief Pain Inventory question 12, an 11-point numeric rating scale was administered in a blinded manner at baseline, end of treatment, and at 3, 6, and 12 mos posttreatment. Treatment success was defined as a minimum 2-point reduction in Brief Pain Inventory question 12 at all posttreatment assessments. Secondary measures included pain-related quality of life (Brief Pain Inventory question 23), subluxation, motor impairment, range of motion, spasticity, and activity limitation.

RESULTS

The electrical stimulation group exhibited a significantly higher success rate than controls (63% vs. 21%, P = 0.001). Repeated-measure analysis of variance revealed significant treatment effects on posttreatment Brief Pain Inventory question 12 (F = 21.2, P < 0.001) and Brief Pain Inventory question 23 (F = 8.3, P < 0.001). Treatment effects on other secondary measures were not significant.

CONCLUSIONS

Intramuscular electrical stimulation reduces hemiplegic shoulder pain, and the effect is maintained for > or =12 mos posttreatment.

Intramuscular neuromuscular electric stimulation for poststroke shoulder pain: A multicenter randomized clinical trial 11A commercial party with a direct financial interests in the results of the research supporting this article has or will confer a benefit on the author or 1 or more of the authors. NeuroControl Corp, Valley View, OH, intends to commercialize the device evaluated in this article and has submitted a premarket 510(K)application, which is currently pending US Food and Drug Administration review. Chae and Feldstein are consultants to NeuroControl. Walker was an employee of NeuroControl, and is now a consultant to NeuroControl. Fang is an employee of NeuroControl. During this study, Yu served as a consultant to NeuroControl and Grill was an employee of NeuroControl, but neither now has an affiliation with NeuroControl

OBJECTIVE

To assess the effectiveness of intramuscular neuromuscular electric stimulation (NMES) in reducing poststroke shoulder pain.

DESIGN

Multicenter, single-blinded, randomized clinical trial.

SETTING

Ambulatory centers of 7 academic rehabilitation centers in the United States.

PARTICIPANTS

Volunteer sample of 61 chronic stroke survivors with shoulder pain and subluxation.

INTERVENTION

Treatment subjects received intramuscular NMES to the supraspinatus, posterior deltoid, middle deltoid, and trapezius for 6 hours a day for 6 weeks. Control subjects were treated with a cuff-type sling for 6 weeks. Main outcome measure Brief Pain Inventory question 12 (BPI 12), an 11-point numeric rating scale administered in a blinded manner at the end of treatment, and at 3 and 6 months posttreatment.

RESULTS

The NMES group exhibited significantly higher proportions of success based on the 3-point or more reduction in BPI 12 success criterion at the end of treatment (65.6% vs 24.1%, P<.01), at 3 months (59.4% vs 20.7%, P<.01), and at 6 months (59.4% vs 27.6%, P<.05). By using the most stringent "no pain" criterion, the NMES group also exhibited significantly higher proportions of success at the end of treatment (34.4% vs 3.4%, P<.01), at 3 months (34.4% vs 0.0%, P<.001), and at 6 months (34.4% vs 10.3%, P<.05).

CONCLUSIONS

Intramuscular NMES reduces poststroke shoulder pain among those with shoulder subluxation and the effect is maintained for at least 6 months posttreatment.

An implantable neuroprosthesis for restoring bladder and bowel control to patients with spinal cord injuries: a multicenter trial

OBJECTIVE

To evaluate the safety and efficacy of an implanted neuroprosthesis for management of the neurogenic bladder and bowel in individuals with spinal cord injury (SCI).

DESIGN

Prospective study comparing bladder and bowel control before and at 3, 6, and 12 months after implantation of the neuroprosthesis.

SETTING

Six US hospitals specializing in treatment of SCI.

PATIENTS

Twenty-three neurologically stable patients with complete suprasacral SCIs.

INTERVENTION

Implantation of an externally controlled neuroprosthesis for stimulating the sacral nerves and posterior sacral rhizotomy.

MAIN OUTCOME MEASURES

Ability to urinate more than 200mL on demand and a resulting postvoid residual volume of less than 50mL.

RESULTS

At 1-year follow-up, 18 of 21 patients could urinate more than 200mL with the neuroprosthesis, and 15 of 21 had postvoid volumes less than 50mL (median, 15mL). Urinary tract infection, catheter use, reflex incontinence, anticholinergic drug use, and autonomic dysreflexia were substantially reduced. At 1-year follow-up, 15 of 17 patients reduced the time spent with bowel management.

CONCLUSIONS

Neural stimulation and posterior rhizotomy is a safe and effective method of bladder and bowel management after suprasacral SCI.

Efficacy of an implanted neuroprosthesis for restoring hand grasp in tetraplegia: a multicenter study

OBJECTIVE

To evaluate an implanted neuroprosthesis that allows tetraplegic users to control grasp and release in 1 hand.

DESIGN

Multicenter cohort trial with at least 3 years of follow-up. Function for each participant was compared before and after implantation, and with and without the neuroprosthesis activated.

SETTING

Tertiary spinal cord injury (SCI) care centers, 8 in the United States, 1 in the United Kingdom, and 1 in Australia.

PARTICIPANTS

Fifty-one tetraplegic adults with C5 or C6 SCIs.

INTERVENTION

An implanted neuroprosthetic system, in which electric stimulation of the grasping muscles of 1 arm are controlled by using contralateral shoulder movements, and concurrent tendon transfer surgery. Assessed participants' ability to grasp, move, and release standardized objects; degree of assistance required to perform activities of daily living (ADLs), device usage; and user satisfaction.

MAIN OUTCOME MEASURES

Pinch force; grasp and release tests; ADL abilities test and ADL assessment test; and user satisfaction survey.

RESULTS

Pinch force was significantly greater with the neuroprosthesis in all available 50 participants, and grasp-release abilities were improved in 49. All tested participants (49/49) were more independent in performing ADLs with the neuroprosthesis than they were without it. Home use of the device for regular function and exercise was reported by over 90% of the participants, and satisfaction with the neuroprosthesis was high.

CONCLUSIONS

The grasping ability provided by the neuroprosthesis is substantial and lasting. The neuroprosthesis is safe, well accepted by users, and offers improved independence for a population without comparable alternatives.

Satisfaction with and usage of a hand neuroprosthesis

OBJECTIVE

To measure the satisfaction with, clinical impact of, and use of an implantable hand neuroprosthesis.

SETTING

Eight different medical centers.

PARTICIPANTS

Thirty-four individuals with spinal cord injuries at the C5 or C6 motor level.

INTERVENTIONS

Participants were implemented with a hand neuroprosthesis that provides grasp and release. The neuroprosthesis includes a surgically implanted stimulator, implanted electrodes sutured to the hand and forearm muscles, and an externally mounted controller.

MAIN OUTCOME MEASURE

A survey was mailed to study participants, who were asked to respond to statements such as "If I had it to do over, I would have the hand system implanted again," using a 5-level Likert scale ("strongly agree" to "strongly disagree").

RESULTS

Eighty-seven percent of participants were very satisfied with the neuroprosthesis, 88% reported a positive impact on their life, 87% reported improvements in activities of daily living, and 81% reported improved independence. Participants reported using the neuroprosthesis a median of 5.5 days per week; 15 participants used the neuroprosthesis 7 days per week, and 5 participants reported not using the device.

CONCLUSIONS

The neuroprosthesis was used by most participants. The neuroprosthesis performed satisfactorily, increased users' ability to perform activities of daily living and independence, and improved their quality of life.

Functional neuromuscular stimulation for combined control of elbow extension and hand grasp in C5 and C6 quadriplegics

Spinal cord injury sustained at the C5/C6 level leaves an individual without voluntary control of the muscles of the forearm, hand, or of the elbow extensors. The objective of this research project was to integrate functional neuromuscular stimulation (FNS) control of elbow extension with a previously developed system that provides hand grasp in order to increase the working volume in space in which users can perform functional tasks. Elbow extension control was achieved by detecting the position of the arm in space and determining the magnitude of the gravitational moment acting to oppose extension. An accelerometer was used as the command control source, and this sensor was placed over the ulna near the elbow joint to detect static (gravitational) acceleration, and therefore the gravitational moment acting about the elbow joint. This value determined the level of electrical stimulation required to activate the triceps muscles to full extension against these forces. Combined FNS control of elbow extension and hand grasp was implemented in two quadriplegic subjects. Both subjects were able to reach and grasp objects at locations in space which were unattainable without triceps activation.