Bulbocavernosus Reflex (2023)

Intraoperative bulbocavernosus reflex (BCR) monitoring is more difficult in females than in males. This study was designed to compare the feasibility of transurethral electrical stimulation BCR (tu-BCR) monitoring with that of conventional BCR (c-BCR) monitoring during spine surgery in females.

Twenty-four females were included. For stimulation in c-BCR monitoring, a pair of surface electrodes was placed on the genitals (cathode/anode: clitoris/adjacent labium). For stimulation in tu-BCR monitoring, a urethral catheter attached to a pair of electrodes was inserted into the urethra. BCRs were recorded from the external anal sphincter after a single train of four stimulation pulses.

There was no postoperative urinary tract injury associated with urethral catheter insertion for tu-BCR. Tu-BCR monitoring had a significantly higher success rate of baseline recording than c-BCR monitoring (87.5% vs 66.7%, respectively, p=0.028). The specificities of tu-BCR and c-BCR monitoring were 100% and 87.2%, respectively. The sensitivity was not calculated because no patients had postoperative urinary or bowel dysfunction.

Our data indicate that tu-BCR monitoring improved the success rate of baseline recording and specificity during spine surgery in females.

Tu-BCR monitoring was more reliable than c-BCR monitoring during spine surgery in females.

Overactive pelvic floor (OPF) muscles are defined as muscles that do not relax, or may even contract, when relaxation is needed, for example, during micturition or defecation. Conditions associated with OPF are multifactorial and include multiple possible etiologies and symptom complexes. The complex interplay between biological and psychosocial elements can lead to the persistence of OPF symptoms along with psychological and emotional distress.

(1) To review and contextualize, from a pathophysiologic perspective, the evidence for OPF, (2) to provide an overview of common clinical presentations and comorbidities of OPF, and (3) to discuss the effect of OPF on sexual function in men and women.

Review of the updated literature on the pathophysiology of OPF was carried out. OPF-associated conditions were overviewed, with special emphasis on the impact on sexual function in men and women.

Individuals with suspected OPF often present with a combination of gastrointestinal, gynecological, musculoskeletal, sexual, and urological comorbidities, mostly accompanied by psychoemotional distress. In both women and men, sexual function is significantly impaired by OPF and genitopelvic pain penetration disorders are often the primary manifestation of this condition. Women with OPF report less sexual desire, arousal, and satisfaction; more difficulty reaching orgasm; lower frequencies of intercourse; more negative attitudes toward sexuality; and more sexual distress than women without sexual pain. The most frequently reported sexual dysfunctions in men with OPF include erectile dysfunction, premature ejaculation, and ejaculatory pain.

The complex pathophysiology of OPF involving multisystemic comorbidities and psychosocial factors emphasize the importance of a biopsychosocial assessment for guiding effective and personalized management.

Padoa A, McLean L, Morin M, etal. “The Overactive Pelvic Floor (OPF) and Sexual Dysfunction” Part 1: Pathophysiology of OPF and Its Impact on the Sexual Response. Sex Med 2021;9:64–75.

Neuropeptides are known to modulate female receptivity. However, even though receptivity is a spinal reflex, the role of neuropeptides within the spinal cord remains to be elucidated.

The aims were to (i) investigate neuropeptides in the lumbosacral region; and (ii) determine how neuropeptides modulate glutamate release from stretch Ia fibers, touch sensation Aβ fibers and Aδ/C pain fibers.

Neuropeptide modulation of the lumbosacral dorsal-root ventral-root reflex in vitro.

Spinal cords were removed from Sprague-Dawley rats in compliance with UK Home Office guidelines. Hemisected cords were superfused with aCSF and the dorsal root (L4–S1) was stimulated to evoke glutamate release. A biphasic reflex response was evoked from the opposite ventral root consisting of a monosynaptic (Ia fibers) and polysynaptic (Aβ, Aδ/C fibers) component.

The µ opioid receptor (MOR) agonist DAMGO inhibited the monosynaptic (EC₅₀ 0.02 ± 0.02 nM) and polysynaptic area (EC₅₀ 125 ± 167 nM) but not polysynaptic amplitude. Oxytocin and corticotrophin releasing factor (CRF) inhibited the monosynaptic amplitude (EC₅₀, 1.4 ± 1.0 nM and EC₅₀ 4.3 ± 3.5 nM, respectively), polysynaptic amplitude (EC₅₀ 18.2 ± 28.0 nM and EC₅₀, 9.5 ± 13.3 nM, respectively), and area (EC₅₀ 11.6 ± 13.0 nM and EC₅₀, 2.8 ± 3.3 nM, respectively); effects that were abolished by oxytocin and CRF₁ antagonists, L-368899 and 8w. Melanocortin agonists solely inhibited the monosynaptic component, which were blocked by the MC_3/4 receptor antagonist SHU9119.

These data suggest endogenous neuropeptides are released within the lumbosacral spinal cord. Melanocortin agonists, oxytocin, CRF, and DAMGO via MC₄, oxytocin, CRF₁, and MOR inhibit glutamate release but with differing effects on afferent fiber subtypes. Melanocortins, oxytocin, CRF, and DAMGO have the ability to modulate orgasm whereas oxytocin, CRF and DAMGO can increase pain threshold. Oxytocin and CRF may dampen touch sensation. Wilson LA, Wayman CP, and Jackson MV. Neuropeptide modulation of a lumbar spinal reflex: Potential implications for female sexual function. J Sex Med **;**:**–**.

Funktionsstörungen des Beckenbodens sind außerordentlich häufig. So wird für Deutschland von über fünf Millionen Patienten mit Inkontinenz ausgegangen. Aktuell werden flächendeckend Kontinenzzentren etabliert, die eine komplette Diagnostik anbieten. Hierzu gehören selbstverständlicherweise auch die neurophysiologischen Untersuchungen, weshalb alle größeren Abteilungen diese Untersuchungen anbieten und beherrschen müssen. Dabei haben die einzelnen Untersuchungen eine sehr unterschiedliche Bedeutung und Aussagekraft. Als Screening -Untersuchung kann das EMG mit konzentrischer Nadelelektrode angesehen werden. Die Pudenduslatenz wird nur selten abgeleitet und untersucht die terminale Strecke des N. pudendus. Die Pudendus-SSEP sind einfach durchführbar und mittlerweile etabliert. Der Einsatz ist jedoch auf spezielle Fragestellungen die sensible Leitung betreffend beschränkt. Alle anderen neurophysiologischen Untersuchungen sind derzeit speziellen Fragestellungen vorbehalten.

Dysfunctional disorders of the pelvic floor are very widespread. In Germany, more than five million people are believed to suffer from incontinence. At present, centers specializing in the field of continence and offering a full range of diagnostic measures are being established all over the country. Neurophysiological examinations are part of these measures, of course, which is why all big departments must provide for them and be familiar with them. Each of these individual examinations has its particular focus and relevance. An EMG with a concentric needle electrode, for instance, can be regarded as a screening test. The latency period of the pudendal nerve is rarely measured and determines the terminal distance of the pudendal nerve. Pudendal nerve SSEP is simple to carry out and has become an established procedure; its application, however, is restricted to particular investigations regarding sensory conduction. All other neurophysiological examinations are presently limited to specific exploration.

Objectives: This study evaluates the method of intraoperative neurophysiological monitoring of the bulbocavemosus reflex (BCR) with reference to stimulation and detection.

Methods: The study was performed on a group of 65 patients, 53 men and 12 women, who underwent surgery for lower thoracic and lumbar spinal trauma, with no neurological deficit prior to or following surgery. Stimulating electrodes were placed on the dorsum of the penis or the clitoris. Single and double stimuli were used, as well as trains of 3, 4 and 5 stimuli. Detecting wire electrodes were introduced into the perianal region.

Results: A single stimulus elicited the BCR in 50%, pairs in 75%, trains of 3 in 95%, and trains of 4 and 5 in 100% of patients. With placement of the detecting electrodes 2.5 cm deep to the skin, the BCR was detected in 13% of hemisphincters in women, and in 81% of hemisphincters in men. With controlled intramuscular placement of detecting electrodes, the BCR was detected in 97% of hemisphincters in men. With bifocal detection the BCR amplitudes were 30–312 mV (median 90), and interside amplitude ratio was 0.05–1 (median 0.66); with monofocal detection, amplitudes and interside amplitude ratio were 30–560 mV (median 200) and 0.15-1 (median 0.86), respectively.

Conclusions: A train of 4 electrical stimuli is optimal in eliciting the BCR in anesthetized patients. The low rate of elicitability in women was most probably due to inefficient stimulation. Detection was improved by controlled intramuscular placement of electrodes. Monofocal detection yielded higher BCR amplitudes. Interside difference and interindividual variability of the BCR amplitude were considerable.

To compare abdominal equilibrium phase (EP) CT images of obese and non-obese patients to identify the reconstruction method that preserves the diagnostic value of images obtained in obese patients.

We compared EP images of 50 obese patients whose body mass index (BMI) exceeded 25 (group 1) with EP images of 50 non-obese patients (BMI < 25, group 2). Group 1 images were subjected to deep learning reconstruction (DLR), hybrid iterative reconstruction (hybrid-IR), and model-based IR (MBIR), group 2 images to hybrid-IR; group 2 hybrid-IR images served as the reference standard. A radiologist recorded the standard deviation of attenuation in the paraspinal muscle as the image noise. The overall image quality was assessed by 3 other radiologists; they used a confidence scale ranging from 1 (unacceptable) to 5 (excellent). Non-inferiority and potential superiority were assessed.

With respect to the image noise, group 1 DLR- were superior to group 2 hybrid-IR images; group 1 hybrid-IR- and MBIR images were neither superior nor non-inferior to group 2 hybrid-IR images. The quality scores of only DLR images in group 1 were superior to hybrid-IR images of group 2 while the quality scores of group 1 hybrid-IR- and MBIR images were neither superior nor non-inferior to group 2 hybrid-IR images.

DLR preserved the quality of EP images obtained in obese patients.

Postoperative pain at the site of bone graft harvest for posterior spine fusion is reported to occur in 6%–39% of cases. However, the area around the posterior, superior iliac spine is a frequent site of referred pain for many structures. Therefore, many postoperative spine patients may have pain in the vicinity of the posterior iliac crest that may not in fact be caused by bone graft harvesting. The literature may then overestimate the true incidence of postoperative iliac crest pain.

We performed a prospective study testing the hypothesis that patients will not report significantly higher visual analog scores over the graft harvest site when compared with the contralateral, non-harvested side.

This is a prospective, randomized cohort study.

Patients aged 18–75 years undergoing elective spinal fusion of one to two levels between L4 and S1 for spinal stenosis and spondylolisthesis were randomized to left-sided or right-sided iliac crest bone graft (ICBG) donor sites and blinded to the side of harvest.

Primary outcome was a 10-point visual analog scale (VAS) for pain over the left and right posterior superior iliac spine.

Bone graft was harvested via spinal access incisions without making a separate skin incision over the crest. Each patient's non-harvested side served as an internal control. Data points were recorded by patients on their study visit sheets preoperatively and at 6 weeks, 3 months, 6 months, and 1 year postoperatively.

Forty patients were enrolled in the study (23 females) with an average follow-up of 8.1 months (1.5–12 months). Mean age was 51.7 years (23–77 years). Left- and right-side ICBG harvesting was performed equally between the 40 patients. The average volume of graft harvested from the left was 35.3 mL (15–70 mL) and 36.1 mL (15–60 mL) from the right. There was no statistical difference between preoperative VAS score on the harvested side compared with the non-harvested side (p=.415). Postoperatively, there were consistently higher VAS scores on the operative side; however, these differences were not statistically significant at 6 weeks (p=.111), 3 months (p=.440), 6 months (p=.887), or 12 months (p=.240). Both groups did, however, show statistically significant improvements in VAS scores over time within the operative and nonoperative sides (p<.05). Graft volume had no effect on the VAS scores (p=.382).

The current literature does not adequately illuminate the incidence of postoperative pain at the site of harvest and the relative magnitude of this pain in comparison with the patient's residual low back pain. This is the first study to blind the patient to the laterality of bone graft harvesting. Our randomized investigation showed that although pain on the surgical side was slightly higher, it was neither clinically nor statistically different from the nonsurgical side. Our conclusion supports surgeons' use of autologous bone graft, which offers a cost-effective, efficacious spinal fusion supplement.

During the surgery for a distal radius fracture, we encountered a large anomalous muscle lying across the distal radius. The muscle was identified as a flexor carpi radialis brevis muscle (FCRB), based on its location, function, and innervation. This experience led us to clarify its prevalence in living subjects and alert surgeons of its presence.

We reviewed wrist MRI scans of 515 hands of 379 patients with carpal tunnel syndrome (CTS). The prevalence of the FCRB was calculated. The cross sectional area (CSA) of the FCRB was compared with that of the hypothenar muscles. Signal intensity and fat infiltration of the FCRB were assessed using semiquantitative methods. The anterior compartment ratio (CSA of the anterior compartment of the forearm was divided by CSA of the forearm. CSA of the FCRB was excluded for measurement) was compared between patients with and without FCRB.

We found seven hands of six patients (1.6%) with a FCRB. All of these tendons were inserted into the second metacarpal base. CSA of FCRB was smaller than that of the hypothenar muscles. Semiquantitative assessment revealed normal signal intensities of the FCRB compared with those of other muscles. The anterior compartment ratio was smaller in patients with FCRB than without FCRB. None of the FCRB in our series demonstrated any sign of tendinitis on MRI. Furthermore, the postoperative clinical course for those patients was uneventful.

Prevalence of FCRB in patients with CTS was 1.6%. FCRB should function as a wrist flexor. Its strength varied according to the individuals but was not greater than that of the hypothenar muscles. It is still unclear if the FCRB could cause the development of CTS. However, it was found that the FCRB could be a mass which occupies and narrows the anterior compartment.

The aim of this study was to identify the relative anatomic locations of relevant vital structures at risk for injury during posterior iliac crest bone graft procurement.

Twenty-one cadavers yielded 39 intact posterior ilia for dissection. The posterior superior iliac spine (PSIS) was used as the primary reference landmark. Measurements were made to the medial branch of the superior cluneal nerves, the superior branch of the middle cluneal nerves, the sciatic notch, and the superior gluteal vessels. Distances from the spinal midline to the superior cluneal nerves were recorded.

The average distances from the PSIS to the superior and middle cluneal nerves, greater sciatic notch, and superior gluteal vessels were 5.7 cm (standard deviation, 1.22 cm), 6.55 cm (standard deviation, 1.53 cm), 5.3 cm (standard deviation, 0.71 cm), and 5.4 cm (standard deviation, 0.95 cm), respectively. The most medial superior cluneal nerve was identified at 3.0 to 4.9 cm from the PSIS in 23% of cases, at 5.0 to 6.9 cm from the PSIS in 61.5% of cases, and farther than 7.0 cm from the PSIS in 15.4% of cases.

This study illustrates that the most medial superior cluneal nerve is often closer to the PSIS than previously described and the same holds true for the greater sciatic notch and superior gluteal vessels. Knowledge of the anatomic locations of these important structures should allow the surgeon to avoid or decrease the complication rate of bone procurement from the posterior ilium.

To determine the association of preoperative hyponatremia with short-term postoperative complications and health care utilization (length of stay, readmissions) after anterior cervical fusion and discectomy (ACDF).

Patients who underwent ACDF were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients who had revision surgery, trauma, vertebral malignancy, or infection were excluded. Eunatremia was defined as sodium (Na) level between 135 and 145 mEq/L, whereas hyponatremia was defined as Na < 135 mEq/L. Preoperatively, patients with hyponatremia were matched 1:1 with patients with eunatremia using propensity score matching based on age, sex, American Society of Anesthesiologists score, and baseline comorbidities. Minor adverse events included superficial infection, dehiscence, urinary tract infection, pneumonia, and renal insufficiency or failure. Serious adverse events included deep wound infection, reintubation, pulmonary embolism, cerebrovascular accident, cardiac arrest, deep vein thrombosis, sepsis, return to operating room, and death within 30 days. Complications were analyzed using bivariate and logistic analysis with significance set at P < 0.05.

Of the 9094 patients undergoing ACDF, 3.64% (n= 331) were preoperatively hyponatremic. Preoperative hyponatremia was an independent risk factor for postoperative pneumonia after ACDF (odds ratio [OR], 4.47; P= 0.020) and extended length of hospital stay >1 SD above the mean (OR, 1.71; P= 0.042). Preoperative hyponatremia was an independent risk factor for having a serious adverse event (OR, 2.40; P= 0.005) and any adverse event (OR, 2.44; P= 0.009).

Preoperative hyponatremia is an independent risk factor for pneumonia and prolonged length of stay after ACDF.

Syphilis is often called the great imitator because of its frequent atypical clinical manifestations that make the disease difficult to recognize. Because Treponema pallidum subsp. pallidum, the infectious agent of syphilis, is yet uncultivated in vitro, diagnosis is usually made using serology; however, in cases where serology is inconclusive or in patients with immunosuppression where these tests may be difficult to interpret, the availability of a molecular tool for direct diagnosis may be of pivotal importance.

Here we present a fluorescence in situ hybridization (FISH) assay that simultaneously identifies and analyzes spatial distribution of T. pallidum in histological tissue sections.

For this assay the species-specific FISH probe TPALL targeting the 16S rRNA of T. pallidum was designed in silico and evaluated using T. pallidum infected rabbit testicular tissue and a panel of non-syphilis spirochetes as positive and negative controls, respectively, before application to samples from four syphilis-patients.

In a HIV positive patient, FISH showed the presence of T. pallidum in inguinal lymph node tissue. In a patient not suspected to suffer from syphilis but underwent surgery for phimosis, numerous T. pallidum cells were found in preputial tissue. In two cases with oral involvement, FISH was able to differentiate T. pallidum from oral treponemes and showed infection of the oral mucosa and tonsils, respectively.

The TPALL FISH probe is now readily available for in situ identification of T. pallidum in selected clinical samples as well as T. pallidum research applications and animal models.