At-home genital nerve stimulation for individuals with SCI and neurogenic detrusor overactivity: A pilot feasibility study

Case Report: The Rehabilitation of a Patient with Acute Transverse Myelitis after COVID-19 Vaccination

We report the case of a 55-year-old man with multi-symptomatic transverse myelitis after vaccination against coronavirus disease 2019 (COVID-19). The patient was diagnosed based on the course of the disease and the results of imaging and laboratory tests. We excluded other most probable causes of the disease. The quick start of diagnosis allowed for early treatment with intravenous steroids and then plasmapheresis and the implementation of modern rehabilitation methods using biofeedback platforms, among others, and an exoskeleton. The patient returned to work, but the rehabilitation process continues to this day due to persistent symptoms that impair the patient's quality of life.

Beneficial carry-over effects of chronic at-home genital nerve stimulation on incontinence in individuals with spinal cord injury: A pragmatic trial

BACKGROUND

Genital nerve stimulation (GNS) is a promising, but under-researched, alternative treatment for neurogenic detrusor overactivity (NDO) in those with spinal cord injury (SCI).

OBJECTIVES

To investigate the urodynamic, quality-of-life (QOL) and carry-over effects of GNS when applied at home for 2 weeks by participants with incomplete SCI and NDO during activities of daily living.

METHODS

Seven men and 1 woman participated in this 1-month protocol study. Urodynamic and QOL data were gathered during week 1 (baseline measurements), followed by 2 weeks of daily GNS at home using a portable device. GNS was applied either on-demand or thrice daily, depending on the individual's sensation. At week 4, post-stimulation tests were repeated to record any carry-over effect from the GNS. Participants maintained voiding diaries throughout the study. Assessments were carried out at the end of each protocol period in a randomized order. Clinical procedures were conducted at Taipei Medical University Hospital (Taipei, Taiwan).

RESULTS

Everyone completed the study but only 7 of the 8 participants completed their voiding diary. Two weeks after GNS, average cystometric bladder capacity was increased by 30 % compared to baseline (P< 0.05). A 1-week carry-over effect was demonstrated as this capacity remained, on average, 35 % greater than baseline in week 4 after GNS was stopped (P< 0.05). Incontinence frequency significantly decreased by the end of week 3 (P< 0.05) but no significant improvements were recorded for either detrusor pressure or bladder compliance.

CONCLUSIONS

Chronic at-home GNS improved cystometric bladder capacity and reduced urinary incontinence for individuals with incomplete SCI and NDO. A carry-over effect of 1 week was observed following GNS treatment. The use of portable GNS treatment that can be applied by the individual at home merits further investigation as alternative treatment for NDO in those with SCI.

Neuroprosthesis for individuals with spinal cord injury

OBJECTIVE

Individuals who sustain a traumatic spinal cord injury (SCI) often have a loss of multiple body systems. Significant functional improvement can be gained by individual SCI through the use of neuroprostheses based on electrical stimulation. The most common actions produced are grasp, overhead reach, trunk posture, standing, stepping, bladder/bowel/sexual function, and respiratory functions.

METHODS

We review the fundamental principles of electrical stimulation, which are established, allowing stimulation to be safely delivered through implanted devices for many decades. We review four common clinical applications for SCI, including grasp/reach, standing/stepping, bladder/bowel function, and respiratory functions. Systems used to implement these functions have many common features, but are also customized based on the functional goals of each approach. Further, neuroprosthetic systems are customized based on the needs of each user.

RESULTS & CONCLUSION

The results to date show that implanted neuroprostheses can have a significant impact on the health, function, and quality of life for individuals with SCI. A key focus for the future is to make implanted neuroprostheses broadly available to the SCI population.

Targeting bladder function with network-specific epidural stimulation after chronic spinal cord injury

Profound dysfunctional reorganization of spinal networks and extensive loss of functional continuity after spinal cord injury (SCI) has not precluded individuals from achieving coordinated voluntary activity and gaining multi-systemic autonomic control. Bladder function is enhanced by approaches, such as spinal cord epidural stimulation (scES) that modulates and strengthens spared circuitry, even in cases of clinically complete SCI. It is unknown whether scES parameters specifically configured for modulating the activity of the lower urinary tract (LUT) could improve both bladder storage and emptying. Functional bladder mapping studies, conducted during filling cystometry, identified specific scES parameters that improved bladder compliance, while maintaining stable blood pressure, and enabled the initiation of voiding in seven individuals with motor complete SCI. Using high-resolution magnetic resonance imaging and finite element modeling, specific neuroanatomical structures responsible for modulating bladder function were identified and plotted as heat maps. Data from this pilot clinical trial indicate that scES neuromodulation that targets bladder compliance reduces incidences of urinary incontinence and provides a means for mitigating autonomic dysreflexia associated with bladder distention. The ability to initiate voiding with targeted scES is a key step towards regaining volitional control of LUT function, advancing the application and adaptability of scES for autonomic function.

Feasibility of Real-Time Conditional Sacral Neuromodulation Using Wireless Bladder Pressure Sensor

Continuous sacral neuromodulation (SNM) is used to treat overactive bladder, reducing urine leakage and increasing capacity. Conditional SNM applies stimulation in response to changing bladder conditions, and is an opportunity to study neuromodulation effects in various disease states. A key advantage of this approach is saving power consumed by stimulation pulses. This study demonstrated feasibility of automatically applying neuromodulation using a wireless bladder pressure sensor, a real-time control algorithm, and the Medtronic Summit™ RC+S neurostimulation research system. This study tested feasibility of four conditional SNM paradigms over five days in 4 female sheep. Primary outcomes assessed proof of concept of closed-loop system function. While the bladder pressure sensor correlated only weakly to simultaneous catheter-based pressure measurement (correlation 0.26-0.89, median r=0.52), the sensor and algorithm were accurate enough to automatically trigger SNM appropriately. The neurostimulator executed 98.5% of transmitted stimulation commands with a median latency of 72 ms (n=1,206), suggesting that rapid decision-making and control is feasible with this platform. On average, bladder capacity increased for continuous SNM and algorithm-controlled paradigms. Some animals responded more strongly to conditional SNM, suggesting that treatment could be individualized. Future research in conditional SNM may elucidate the physiologic underpinnings of differential response and enable clinical translation.

Needs, priorities, and attitudes of individuals with spinal cord injury toward nerve stimulation devices for bladder and bowel function: a survey

Study Design:

Survey.

Objectives:

To investigate the needs and priorities of people with spinal cord injury for managing neurogenic bladder and bowel function and to determine their willingness to adopt neuromodulation interventions for these functions.

Methods:

Anonymous online survey. It was advertised by word-of-mouth by community influencers and social media, and by advertisement in newsletters of advocacy groups.

Results:

Responses from 370 individuals (27% female, 73% male) were included. Bladder emptying without catheters was the top priority for restoring bladder function, and maintaining fecal continence was the top priority for restoring bowel function. The biggest concerns regarding external stimulation systems were wearing a device with wires connecting to electrodes on the skin and having to don and doff the system daily as needed. The biggest concerns for implanted systems were the chances of experiencing problems with the implant that required a revision surgery or surgical removal of the whole system. Respondents were willing to accept an external (61%) or implanted (41%) device to achieve improved bladder or bowel function.

Conclusions:

Bladder and bowel dysfunction remain important unmet challenges for individuals living with SCI who answered our survey. These individuals are willing to accept some potential risks of nerve stimulation approaches given potential benefits. Additional consumer input is critical for guiding both research and translation to clinical use and personalized medicine.

Current management of refractory overactive bladder

Overactive bladder (OAB) is a common condition affecting one-sixth to one-fifth of the global population. The treatment of refractory OAB remains a challenge for urologists. Current treatment options include the use of combination therapy with antimuscarinic agents and beta-3 adrenoceptor agonists, and treating underlying curable disorders. Intravesical botulinum toxin type A (BoNT-A) injection, percutaneous tibial nerve stimulation, and sacral nerve stimulation are third-line management therapies suggested by the American Urological Association/Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction (AUA/SUFU) guidelines. In rare cases, more invasive surgical interventions can be considered after explaining the benefits and risks to the patients. Augmentation cystoplasty has a high success rate; however, it has also been associated with a high complication rate. In contrast, detrusor myomectomy is an easy procedure, but the treatment outcome remains controversial. Liposome-encapsulated BoNT-A is administered via bladder instillation, and promising results have been obtained in preliminary studies. More therapies are currently being investigated, and transient receptor potential vanilloid 1 antagonists may be new type of medication. Radiofrequency ablation and other targets for neuromodulation have also been studied; however, more evidence is needed to confirm their efficacy.

Ambulatory urodynamic monitoring assessment of dorsal genital nerve stimulation for suppression of involuntary detrusor contractions following spinal cord injury: a pilot study

STUDY DESIGN

A prospective interventional pilot study using within-individual comparisons.

OBJECTIVES

To assess the effect of dorsal genital nerve stimulation (DGNS) on urine-storage parameters in participants with spinal cord injury (SCI) and neurogenic detrusor overactivity (NDO) during natural bladder filling.

SETTING

The London Spinal Cord Injuries Centre at the Royal National Orthopaedic Hospital, Stanmore, UK.

METHODS

Ambulatory urodynamic monitoring (AUM) was carried out with and without DGNS, before and after a week of using DGNS at home. DGNS was applied on-demand by four participants with bladder sensation, and both continuously and intermittently by one participant with absent sensation. A Wilcoxon sign-rank test was used to test paired results of changes within an AUM session.

RESULTS

Urodynamic outcomes were improved using DGNS. Bladder capacity was increased from 244 ± 59 to 346 ± 61 ml (p = 0.0078), a mean change of 46 ± 25%. Maximum detrusor pressure was decreased from 58 ± 18 to 47 ± 18 cmH2O (p = 0.0156), a change of 17 ± 13%, and average peak detrusor pressure was decreased from 56 ± 16 to 31 ± 128 cmH2O (p = 0.0156), a mean reduction of 50 ± 19%. There was an increase in the number of detrusor contractions from the first involuntary detrusor contraction to a strong desire, urgency or incontinence, from 1.5 ± 1.4 to 4.3 ± 1.7, and an increase in time of 23 ± 22 min. There were no changes in baseline outcomes following home use of DGNS.

CONCLUSIONS

DGNS may be applied on-demand, intermittently or continuously, to increase bladder capacity, decrease storage pressures and provide extra time. Improvements were made in addition to existing antimuscarinic medication regimes.

The 2019 yearbook of Neurorestoratology

Time is infinite movement in constant motion. We are glad to see that Neurorestoratology, a new discipline, has grown into a rich field involving many global researchers in recent years. In this 2019 yearbook of Neurorestoratology, we introduce the most recent advances and achievements in this field, including findings on the pathogenesis of neurological diseases, neurorestorative mechanisms, and clinical therapeutic achievements globally. Many patients have benefited from treatments involving cell therapies, neurostimulation/neuromodulation, brain–computer interface, neurorestorative surgery or pharmacy, and many others. Clinical physicians can refer to this yearbook with the latest knowledge and apply it to clinical practice.

A Urodynamic Comparison of Neural Targets for Transcutaneous Electrical Stimulation to Acutely Suppress Detrusor Contractions Following Spinal Cord Injury

Objectives

To assess and compare the effect of transcutaneous Dorsal Genital Nerve Stimulation (DGNS), Tibial Nerve Stimulation (TNS), Sacral Nerve Stimulation (SNS), and Spinal Stimulation (SS) on Neurogenic Detrusor Overactivity (NDO) and bladder capacity in people with Spinal Cord Injuries (SCI).

Materials and Methods

Seven male participants with supra-sacral SCI were tested. Standard cystometry (CMG) was performed to assess bladder activity at baseline and with stimulation applied at each site. This was conducted over four separate sessions. All stimulation was monophasic, 15 Hz, 200 μS pulses and applied at maximum tolerable amplitude. Results were analysed against individual control results from within the same session.

Results

Dorsal Genital Nerve Stimulation increased bladder capacity by 153 ± 146 ml (p = 0.016) or 117 ± 201%. DGNS, TNS and SNS all increased the volume held following the first reflex contraction, by 161 ± 175, 46 ± 62, and 34 ± 33 ml (p = 0.016, p = 0.031, p = 0.016), respectively. SS results showed small reduction of 33 ± 26 ml (p = 0.063) from baseline bladder capacity in five participants. Maximum Detrusor Pressure before leakage was increased during TNS, by 10 ± 13 cmH₂O (p = 0.031) but was unchanged during stimulation of other sites. DGNS only was able to suppress at least one detrusor contraction in five participants and reduced first peak detrusor pressure below 40 cmH₂O in these 5. Continuous TNS, SNS, and SS produced non-significant changes in bladder capacity from baseline, comparable to conditional stimulation. Increase in bladder capacity correlated with stimulation amplitude for DGNS but not TNS, SNS or SS.

Conclusion

In this pilot study DGNS acutely suppressed detrusor contractions and increased bladder capacity whereas TNS, SNS, and SS did not. This is the first within individual comparison of surface stimulation sites for management of NDO in SCI individuals.

Effects of Genital Nerve Stimulation Amplitude on Bladder Capacity in Spinal Cord Injured Subjects

Background/Purpose

Few studies have investigated the effects of changing the amplitude of dorsal genital nerve stimulation (GNS) on the inhibition of neurogenic detrusor overactivity in individuals with spinal cord injury (SCI). The present study determined the acute effects of changes in GNS amplitude on bladder capacity gain in individuals with SCI and neurogenic detrusor overactivity.

Methods

Cystometry was used to assess the effects of continuous GNS on bladder capacity during bladder filling. The cystometric trials were conducted in a randomized sequence of cystometric fills with continuous GNS at stimulation amplitudes ranging from 1 to 4 times of threshold (T) required to elicit the genitoanal reflex.

Results

The bladder capacity increased minimally and maximally by approximately 34% and 77%, respectively, of the baseline bladder capacity at 1.5 T and 3.2 T, respectively. Stimulation amplitude and bladder capacity were significantly correlated (R = 0.55, P = 0.01).

Conclusion

This study demonstrates a linear correlation between the stimulation amplitude ranging from 1 to 4T and bladder capacity gain in individuals with SCI in acute GNS experiments. However, GNS amplitude out of the range of 1-4T might not be exactly a linear relationship due to subthreshold or saturation factors. Thus, further research is needed to examine this issue. Nevertheless, these results may be critical in laying the groundwork for understanding the effectiveness of acute GNS in the treatment of neurogenic detrusor overactivity.