Peripheral and Sacral Neuromodulation in the Treatment of Neurogenic Lower Urinary Tract Dysfunction

Safety of Magnetic Resonance Imaging in patients under Sacral Neuromodulation with an InterStim Neuromodulator

OBJECTIVE

To retrospectively investigate the safety of magnetic resonance imaging (MRI) in patients under sacral neuromodulation (InterStim II).

METHODS

Data of patients who received a sacral neuromodulator at the urological department of a Swiss center of tertiary care from 2007 to 2018 and subsequently received at least 1 MRI with implanted device were retrospectively analyzed. Patient characteristics, data on implantation, MRI characteristics and complications potentially related to the MRI were analyzed. In addition, patient interviews were performed to verify the data gathered from patient records.

RESULTS

A total of 55 consecutive patients with a median age of 48 years (range 16 - 80 years) and a total of 191 MRIs (median 3, range 1 - 13) were included to the study. The majority of MRIs (92%) were performed with 1.5 Tesla. The majority of the 1.5 Tesla (58%) as well as 3 Tesla (56%) MRIs assessed body regions other than the head. Complication possibly related to the MRI were only found in 2 (1%) MRI scans in two patients who reported on transient electrifying pain and heat sensation at the implantation site of the neuromodulator during MRI.

CONCLUSION

MRI scans in patients with an implanted InterStim II sacral neuromodulator and with the device being turned off seem to be safe, even if they involve body regions other than the head, at least with 1.5 Tesla.

Effect of sacral neuromodulation on bowel dysfunction in patients with neurogenic bladder

AIM

The aim of this retrospective study was to evaluate the clinical effect of sacral neuromodulation (SNM) on bowel dysfunction in patients with neurogenic bladder using the neurogenic bowel dysfunction (NBD) score.

METHOD

Between July 2012 and July 2019, 41 patients with both neurogenic bladder and bowel dysfunction underwent permanent SNM implantation. The NBD score was used to evaluate the bowel symptoms before the testing phase and at follow-up. The first follow-up was at the time of discharge after permanent implantation. The second follow-up was conducted by telephone after discharge.

RESULTS

The mean NBD score before the testing phase was 11.0 ± 5.83, whilst it significantly decreased to 5.2 ± 5.32 (n = 41, P < 0.05) at the first follow-up (32 ± 3.9 days). Before the testing phase, there were 9 patients with very minor NBD, 10 with minor NBD, 13 with moderate NBD and 9 with severe NBD. At the first follow-up, there were 26 patients with very minor NBD, 7 with minor NBD, 4 with moderate NBD and 4 with severe NBD (P < 0.05). Twenty-six patients were interviewed in the long-term follow-up (34 ± 30.9 months). The NBD score in these 26 patients was 5.6 ± 5.18, which was not significantly different from the NBD score (5.5 ± 5.33) at the first follow-up (n = 26, P > 0.05).

CONCLUSION

SNM facilitates a significant reduction in NBD score in patients with neurogenic bladder and bowel dysfunction. The improvement in NBD symptoms can also be used as a future indicator to determine the clinical efficacy of permanent SNM implantation in the treatment of neurogenic bladder.

Ultracompliant Carbon Nanotube Direct Bladder Device

The bladder, stomach, intestines, heart, and lungs all move dynamically to achieve their purpose. A long-term implantable device that can attach onto an organ, sense its movement, and deliver current to modify the organ function would be useful in many therapeutic applications. The bladder, for example, can suffer from incomplete contractions that result in urinary retention with patients requiring catheterization. Those affected may benefit from a combination of a strain sensor and electrical stimulator to better control bladder emptying. The materials and design of such a device made from thin layer carbon nanotube (CNT) and Ecoflex 00-50 are described and demonstrate its function with in vivo feline bladders. During bench-top characterization, the resistive and capacitive sensors exhibit stability throughout 5000 stretching cycles under physiology conditions. In vivo measurements with piezoresistive devices show a high correlation between sensor resistance and volume. Stimulation driven from platinum-silicone composite electrodes successfully induce bladder contraction. A method for reliable connection and packaging of medical grade wire to the CNT device is also presented. This work is an important step toward the translation of low-durometer elastomers, stretchable CNT percolation, and platinum-silicone composite, which are ideal for large-strain bioelectric applications to sense or modulate dynamic organ states.

[Anorectal disorders in patients with multiple sclerosis: Physiopathology, prevalence, impact, and management]

OBJECTIVE

Neurogenic bowel disorders (NBD) are frequently observed in patients with multiple sclerosis (MS); the prevalence of constipation is estimated to be 35-54 % and fecal incontinence between 29 and 51 % (LE 4). They contribute to the deterioration of patients' quality of life (LE 4). The aim of this article is to review the literature on the physiopathology, prevalence, impact, and management of bowel disorders in patients with MS in order to educate caregivers about their existence and thus help them to optimize therapeutic choices.

MATERIALS AND METHODS

A bibliographic search was conducted between 2000 and 2019 and 31 relevant scientific articles were selected. Relevant references were subsequently added, bringing the total to 50 articles. A level of scientific evidence (LE) was assigned to each article, except for literature reviews.

RESULTS

The origin of NBD is multifactorial and includes impairment of neurological pathways, polypharmacy, behavioural disorders, and loss of autonomy (LE 4). Patients with MS should be questioned about their bowel habits and, in cases of proven NBD, specific management options should be offered. The first step concerns the dietary and lifestyle rules associated with the use of laxatives, suppositories, and/or enemas (LE 4). In the event of failure, therapies such as abdominal massages (LE 1 and 2), biofeedback and transanal irrigation can be proposed (LE 4). Anterograde colonic irrigation may also be an option (LE 4). The efficacy of stimulating the posterior tibial nerve needs to be proven (LE 4). The implantation of a sacral neuromodulation device is, for the moment, difficult due to the impossibility of performing a spinal magnetic resonance imaging during follow-up. A stoma improves the quality of life of patients and should not be proposed too late.

CONCLUSION

Effective treatment of NBD improves the quality of life of patients and reduces the incidence of bladder disorders (LE 4).

Effect of Early Sacral Neuromodulation on Bladder Function in a Rat Model of Incomplete Spinal Cord Injury Due to Focal Contusion

OBJECTIVES

Incomplete spinal cord injury (SCI) accounts for two-thirds of all SCIs in clinical practice. Preclinical research on the effect of sacral neuromodulation (SNM) on bladder function, however, has been focused only on animal models of complete SCI. We aimed to evaluate the effect of early SNM on bladder responses in a rat model of incomplete SCI.

MATERIALS AND METHODS

Altogether, 21 female Sprague-Dawley rats were equally assigned to control (CTR), SCI + sham stimulation (SHAM), and SCI + SNM (SNM) groups. In the SHAM and SNM groups, incomplete SCI was created by producing a moderate contusion with an NYU-MASCIS impactor at the T9-T10 level of the spine, with needle electrodes implanted bilaterally into the S2 or S3 sacral foramen. Only SNM group underwent electrical stimulation for 28 days, beginning on day 7 after SCI. Cystometry was performed 35 days after SCI.

RESULTS

Although the interval between voiding contractions was significantly longer in the SHAM group than the CTR group (25.5 ± 1.4 vs. 12.5 ± 1.7 min; p < 0.05), there were no significant differences between the SNM group (16.5 ± 1.5 min) and the CTR group. Maximum voiding contraction pressure did not differ among the groups. The SNM group had a significantly lower frequency (3.5 ± 0.5 vs. 14.6 ± 2.0; p < 0.05) and maximum pressure (11.4 ± 6.2 vs. 21.3 ± 1.8 cmH₂ O; p < 0.05) of nonvoiding contractions than the SHAM group.

CONCLUSIONS

Our results provide experimental evidence that early SNM treatment may prevent or diminish bladder dysfunctions (e.g., detrusor overactivity, abnormal micturition reflex) in a clinical condition of incomplete SCI.

Neurogenic bowel dysfunction in patients with multiple sclerosis: prevalence, impact, and management strategies

Bowel dysfunction in patients with multiple sclerosis (MS) is highly prevalent. Constipation and fecal incontinence can coexist and alternate, impacting on the patient's quality of life and social interactions, as well as burdening the caregivers. The cost for the health care providers is also significant, with increased number of hospital admissions, treatment-related costs, and hospital appointments. The origin is multifactorial, and includes alteration of neurological pathways, polypharmacy, behavioral elements, and ability to access the toilet. Every patient with MS should be sensitively questioned about bowel function, and red flag symptoms should prompt adequate investigations. Manipulation of life style factors and establishment of a bowel regime should be attempted in the first place, and if this fails, other measures such as biofeedback and transanal irrigation should be included. A stoma can improve quality of life, and is not necessarily a last-ditch option. Antegrade colonic enemas can also be an effective option, whilst neuromodulation has not proved its role yet. Effective treatment of bowel dysfunction improves quality of life, reduces incidence of urinary tract infection, and reduces health care costs.

Training with brain-machine interfaces, visuo-tactile feedback and assisted locomotion improves sensorimotor, visceral, and psychological signs in chronic paraplegic patients

Spinal cord injury (SCI) induces severe deficiencies in sensory-motor and autonomic functions and has a significant negative impact on patients' quality of life. There is currently no systematic rehabilitation technique assuring recovery of the neurological impairments caused by a complete SCI. Here, we report significant clinical improvement in a group of seven chronic SCI patients (six AIS A, one AIS B) following a 28-month, multi-step protocol that combined training with non-invasive brain-machine interfaces, visuo-tactile feedback and assisted locomotion. All patients recovered significant levels of nociceptive sensation below their original SCI (up to 16 dermatomes, average 11 dermatomes), voluntary motor functions (lower-limbs muscle contractions plus multi-joint movements) and partial sensory function for several modalities (proprioception, tactile, pressure, vibration). Patients also recovered partial intestinal, urinary and sexual functions. By the end of the protocol, all patients had their AIS classification upgraded (six from AIS A to C, one from B to C). These improvements translated into significant changes in the patients' quality of life as measured by standardized psychological instruments. Reexamination of one patient that discontinued the protocol after 12 months of training showed that the 16-month break resulted in neurological stagnation and no reclassification. We suggest that our neurorehabilitation protocol, based uniquely on non-invasive technology (therefore necessitating no surgical operation), can become a promising therapy for patients diagnosed with severe paraplegia (AIS A, B), even at the chronic phase of their lesion.

Hypoxic preconditioned bone mesenchymal stem cells ameliorate spinal cord injury in rats via improved survival and migration

The unique hypoxic inflammatory microenvironment observed in the spinal cord following spinal cord injury (SCI) limits the survival and efficacy of transplanted bone mesenchymal stem cells (BMSCs). The aim of the present study was to determine whether hypoxic preconditioning (HP) increased the therapeutic effects of BMSC on SCI. BMSCs were pretreated with cobalt chloride (CoCl2) in vitro, and the proliferative apoptotic and migratory abilities of these hypoxic BMSCs (H‑BMSCs) were assessed. BMSCs and H‑BMSCs derived from green fluorescent protein (GFP) rats were transplanted into SCI rats in vivo. The neurological function, histopathology, inflammation, and number and migration of transplanted cells were examined. HP significantly enhanced BMSC migration (increased hypoxia inducible factor 1α and C‑X‑C motif chemokine receptor 4 expression) and tolerance to apoptotic conditions (decreased caspase‑3 and increased B‑cell lymphoma 2 expression) in vitro. In vivo, H‑BMSC transplantation significantly improved neurological function, decreased spinal cord damage and suppressed the inflammatory response associated with microglial activation. The number of GFP‑positive cells in the SCI core and peripheral region of H‑BMSC animals was increased compared with that in those of BMSC animals, suggesting that HP may increase the survival and migratory abilities of BMSCs and highlights their therapeutic potential for SCI.