Taste Disorders After Middle Ear Surgery: Chorda Tympani Nerve Injury and Quality of Life.

OBJECTIVE: To evaluate taste disorders after middle ear surgery, their modifying factors especially chorda tympani nerve injury or underlying otologic disease. We investigated consequences of taste disorders on quality of life. STUDY DESIGN: Prospective cohort study. SETTING: Monocentric study in tertiary care center. METHODS: A total of 214 patients who underwent middle ear surgery were included. Data regarding taste disorders were collected by questionnaires over a 1-year follow-up period. RESULTS: Taste disorders were reported in 42.7% at 10 days, in 23.3% at 4 months, and in 9.2% 1 year postoperatively. When the chorda tympani nerve was initially healthy, taste disorders were more frequent after its transection throughout the follow-up period. When it was involved in a cholesteatoma or inflammatory process, postoperative taste disorders were more frequent after nerve stretching. Postoperative discomfort in daily life was rated on the Likert scale at 3.5 out of 10. Dietary modifications were reported by 25.8% of patients, and mood alterations by 15% of patients. CONCLUSION: Taste disorders are frequent after middle ear surgery although they mostly improve in the first months. When the CTN is healthy, cutting it leads to more taste disorders than stretching it, thus advocating its preservation to prevent these symptoms. However, in cases of pathological CTN, cutting this nerve, which is sometimes necessary to control the disease, is less likely to cause taste disorders than stretching it. These taste disorders are a source of discomfort and may present risks of dietary modifications and emotional impact.

Understanding the Anatomy of Retroperitoneal Interfascial Space: Implications for Regional Anesthesia.

BACKGROUND: Fascial plane block techniques have evolved considerably in recent years. Unlike the conventional peripheral nerve block methods, the fascial plane block's effect can be predicted based on fascial anatomy and does not require a clear vision of the target nerves. The anatomy of the retroperitoneal interfascial space is complex, since it comprises multiple compartments, including the transversalis fascia (TF), the retroperitoneal fasciae (RF), and the peritoneum. For this reason, an in-depth, accurate understanding of the retroperitoneal interfascial space's anatomical characteristics is necessary for perceiving the related regional blocks and mechanisms that lie underlie the dissemination of local anesthetics (LAs) outside or within the various retroperitoneal compartments. OBJECTIVES: This review aims to summarize the retroperitoneum's anatomical characteristics and elucidate the various communications among different interfascial spaces as well as their clinical significance in regional blocks, including but not limited to the anterior quadratus lumborum block (QLB), the fascia iliaca compartment block (FICB), the transversalis fascia plane block (TFPB), and the preperitoneal compartment block (PCB). STUDY DESIGN: This is a narrative review of pertinent studies on the use of retroperitoneal spaces in regional anesthesia (RA). METHODS: We conducted searches in multiple databases, including PubMed, MEDLINE, and Embase, using "retroperitoneal space," "transversalis fascia," "renal fascia," "quadratus lumborum block," "nerve block," and "liquid diffusion" as some of the keywords. RESULTS: The anatomy of the retroperitoneal interfascial space has a significant influence on the injectate spread in numerous RA blocking techniques, particularly the QLB, FICB, and TFPB approaches. Furthermore, the TF is closely associated with the QLB, and the extension between the TF and iliac fascia offers a potential pathway for LAs. LIMITATIONS: The generalizability of our findings is limited by the insufficient number of randomized controlled trials (RCTs). CONCLUSIONS: Familiarity with the anatomy of the retroperitoneal fascial space could enhance our understanding of peripheral nerve blocks. By examining the circulation in the fascial space, we may gain a more comprehensive understanding of the direction and degree of injectate diffusion during RA as well as the block's plane and scope, possibly resulting in effective analgesia and fewer harmful clinical consequences.

Increase of HCN current in SOD1-associated amyotrophic lateral sclerosis.

The clinical manifestations of sporadic amyotrophic lateral sclerosis (ALS) vary widely. However, the current classification of ALS is mainly based on clinical presentations, while the roles of electrophysiological and biomedical biomarkers remain limited. Herein, we investigated a group of patients with sporadic ALS and an ALS mouse model with superoxide dismutase 1 (SOD1)/G93A transgenes using nerve excitability tests (NET) to investigate axonal membrane properties and chemical precipitation, followed by enzyme-linked immunosorbent assay analysis to measure plasma misfolded protein levels. Six of 19 patients (31.6%) with sporadic ALS had elevated plasma misfolded SOD1 protein levels. In sporadic ALS patients, only those with elevated misfolded SOD1 protein levels showed an increased inward rectification in the current-threshold (I/V) curve and an increased threshold reduction in the hyperpolarizing threshold electrotonus (TE) in the NET study. Two familial ALS patients with SOD1 mutations also exhibited similar electrophysiological patterns of NET. For patients with sporadic ALS showing significantly increased inward rectification in the I/V curve, we noted an elevation in plasma misfolded SOD1 level, but not in total SOD1, misfolded C9orf72, or misfolded phosphorylated TDP43 levels. Computer simulations demonstrated that the aforementioned axonal excitability changes are likely associated with an increase in hyperpolarization-activated cyclic nucleotide-gated (HCN) current. In SOD1/G93A mice, NET also showed an increased inward rectification in the I/V curve, which could be reversed by a single injection of the HCN channel blocker, ZD7288. Daily treatment of SOD1/G93A mice with ZD7288 partially prevented the early motor function decline and spinal motor neuron death. In summary, sporadic ALS patients with elevated plasma misfolded SOD1 exhibited similar patterns of motor axonal excitability changes as familial ALS patients and ALS mice with mutant SOD1 genes, suggesting the existence of SOD1-associated sporadic ALS. The observed NET pattern of increased inward rectification in the I/V curve was attributable to an elevation in the HCN current in SOD1-associated ALS.

A case of a lidocaine intoxication of a 12 week old boy due to a circumcision in a domestic setting - clinical, toxicological and forensic aspects.

Lidocaine is a local anaesthetic commonly used during circumcision for dorsal penile nerve block (DPNB). We describe a case of a 12-week-old infant who presented generalized seizures due to local anesthetic systemic toxicity after Lidocaine administration for circumcision in a non-hospital setting. Serum concentrations of Lidocaine (16.4 mg/L) and its main active metabolite monoethylglycinexylidide (MEGX, 1.36 mg/L) were determined by HPLC-DAD, in a sample collected shortly after administration, which were higher than in comparable cases reported in literature. The reason for the overdose was assumed to be accidental systemic application. Due to suspicion of an improperly performed circumcision and bodily harm, police was involved and a clinical forensic examination was carried out. Here, we present analytical, clinical and forensic aspects of this case.

Recovery of cranial nerve neuropathies after LINAC-based stereotactic radiosurgery for benign cavernous sinus meningioma.

PURPOSE: Cranial Nerve Neuropathies (CNNs) often accompany Cavernous Sinus Meningioma (CSM), for which Stereotactic Radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSR) are established treatments. This study assesses CNNs recovery in CSM patients treated with LINAC, offering insight into treatment effectiveness. METHODS: This study was conducted on 128 patients with CSM treated with LINAC-based SRS/FSR between 2005 and 2020 at a single institution. 46 patients presented with CNNs. The study analyzed patients' demographics, clinical parameters, SRS/FSR treatment characteristics, post-treatment CNNs recovery duration, status, and radiological control on their last follow-up. RESULTS: The median follow-up duration was 53.4 months. Patients were treated with SRS (n = 25) or FSR (n = 21). The mean pretreatment tumor volume was 9.5 cc decreasing to a mean end-of-follow-up tumor volume was 5.1 cc. Radiological tumor control was achieved in all cases. CNN recovery was observed in 80.4% of patients, with specific nerve recoveries documented as follows: extra-ocular nerves (43.2%), trigeminal nerve (32.4%), and optic nerve (10.8%). A higher CNNs recovery rate was associated with a smaller pre-treatment tumor volume (p < 0.001), and the median time-to-improvement was 3.7 months. Patients with tumor volumes exceeding 6.8 cc and those treated with FSR exhibited prolonged time-to-improvement (P < 0.03 and P < 0.04 respectively). CONCLUSIONS: This study suggests that SRS/FSR for CSM provides good and sustainable CNNs recovery outcomes with excellent long-term radiological control. A higher CNNs recovery rate was associated with a smaller pre-treatment tumor volume. while shorter time-to-improvement was identified in patients treated with SRS compared to FSR, particularly in those with small pre-treatment tumor volume.

Transcutaneous auricular vagus nerve stimulation can modulate fronto-parietal brain networks.

Objective: Recent studies have shown that transcutaneous vagal nerve stimulation (tVNS) holds promise as a treatment for neurological or psychiatric disease through the ability to modulate neural activity in some brain regions without an invasive procedure. The objective of this study was to identify the neural correlates underlying the effects of tVNS. Methods: Twenty right-handed healthy subjects with normal hearing participated in this study. An auricle-applied tVNS device (Soricle, Neurive Co., Ltd., Gyeongsangnam-do, Republic of Korea) was used to administer tVNS stimulation. A session consisted of 14 blocks, including 7 blocks of tVNS stimulation or sham stimulation and 7 blocks of rest, and lasted approximately 7 min (1 block = 30 s). Functional magnetic resonance imaging (fMRI) was performed during the stimulation. Results: No activated regions were observed in the fMRI scans following both sham stimulation and tVNS after the first session. After the second session, tVNS activated two clusters of brain regions in the right frontal gyrus. A comparison of the activated regions after the second session of each stimulation revealed that the fMRI following tVNS exhibited four surviving clusters. Additionally, four clusters were activated in the overall stimulated area during both the first and second sessions. When comparing the fMRI results after each type of stimulation, the fMRI following tVNS showed four surviving clusters compared to the fMRI after sham stimulation. Conclusion: tVNS could stimulate some brain regions, including the fronto-parietal network. Stimulating these regions for treating neurological or psychiatric disease might require applying tVNS for at least 3.5 min.

Extensor Retinaculum Syndrome of the Ankle: An Adult Case Series.

Background: Extensor retinaculum syndrome (ERS) is a relatively rarely diagnosed compartment syndrome-like entity caused by elevated pressures in the tissues deep to the superior extensor retinaculum (SER). ERS is identified as out-of-proportion anterior ankle pain, pain with passive toe plantarflexion, elevated SER pressures (>40 mm Hg), and ultimately toe extension weakness and first web space numbness. Although previously described in a pediatric population, this case series is the first to our knowledge in an adult population. Methods: Seven nonconsecutive cases over 18 years from 2 surgeons are reported who underwent complete SER release for ERS either through the direct lateral approach to the fibula or the anterolateral approach to the distal tibia. All were associated with traumatic injuries including 3 bimalleolar ankle fractures, 3 tibial pilon fractures, and 1 distal tibial/fibular shaft fracture. All patients developed writhing anterior ankle pain worsened with passive toe plantarflexion. SER compartment pressures ranged from 50 to >135 mm Hg. Five cases displayed decreased first web space sensation. Results: The diminished or absent first web space sensation uniformly improved post-release. Complications included 1 patient with complex regional pain syndrome type 1, 1 patient required hardware removal, and 2 had persistent but improved first web space sensation changes. Conclusion: Clinical suspicion for possible ERS should arise after distal tibial/fibular fractures when the excruciating pain localizes to the ankle instead of the classic anterior leg muscle bellies. If pain is worsened with passive toe plantarflexion, this diagnosis should be considered. Recommended treatment involves complete release of the SER anywhere on the anterior surface between the tibia and fibula depending on the approach needed for fixation of the associated fracture. Level of Evidence: Level IV, case series.

Comparison between Intra-Articular Steroid Injection and Supra-Scapular Nerve Block in the Management of Frozen Shoulder.

Objective: To compare the efficacy of intra-articular steroid injection with ultrasound-guided supra-scapular nerve block in the management of frozen shoulder in terms of shoulder pain and disability index score and range of motion. Method: This randomized controlled trial was conducted in orthopedic department, PIMS, Islamabad from 1st January, 2020 to 30th June, 2020. A total of 72 patients were randomly equally (n=36 each) allocated to Group-A (intra-articular steroid injection) and Group-B (supra-scapular nerve block). Adults above 18 years of both genders having diffuse shoulder pain were included. Cases of shoulder pain localized because of bicipital tendinitis, rotator cuff tear, pain due to acute trauma and those with osteoarthritis were excluded. Data was analyzed in SPSS version 22.0. Results: Patients average age was 60.1 ± 6.29 in IASI and 58.0 ± 5.83 years in SSNB Group-And there were 19 (52.8%) males in IASI group compared to 15 (41.7%) in SSNB. At three weeks mean pain was significantly less in SSNB (57.1 ± 9.53 vs 49.4 ± 9.02) compared to IASI group (p-value, <0.001). The mean disability index was significantly low in SSNB (51.5 ± 5.10 vs 63.9 ± 5.14) versus IASI group (p-value, <0.001). At one week, three weeks and six weeks, mean external rotation was better in SSNB than IASI group (p-value, <0.001). The mean abduction was also better in SSNB group. Conclusion: Ultrasound guided supra-scapular nerve block is better than intra-articular steroid injection in managing frozen shoulder.

Case Report: Atypical visual presentation caused by a large convexity meningioma-a nerve stretching and stalk indentation effect.

Visual field defects are commonly present in patients with brain tumors, particularly due to direct compression on the optic apparatus. However, there are instances where brain tumors, despite not directly compressing the optic pathway, can still cause visual symptoms, albeit rarely reported but not uncommonly observed. These mechanisms are thought to be associated with increased intracranial pressure (IICP). We report a case of a 32-year-old man who presented with right blurred vision and was diagnosed with a right convexity meningioma. Upon reviewing his magnetic resonance images, we hypothesized that the indentation of the pituitary stalk on the optic chiasm and the stretching of the optic nerve, combined with a focal effect of IICP, could be responsible for his atypical visual field defect.

The Posteromedial Approach for Harvesting Hamstring Autografts Results in Fewer Incidents of Saphenous Nerve Injury Compared to the Conventional Anteromedial Approach: A Systematic Review and Meta-Analysis.

Background: The hamstring autograft can be harvested using various skin incisions, such as vertical, transverse, and oblique incisions, and from different localizations, including anteromedial and posteromedial harvest sites. The aim of this study was to compare studies on the anteromedial and posteromedial approaches for hamstring autograft harvest in terms of clinical outcomes, saphenous nerve injury, infection, operative time, graft length, incision length, range of motion, and patient satisfaction. Methods: Following the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, a search was conducted in PubMed and Scopus, focusing on studies comparing anteromedial and posterior approaches for hamstring harvest. This study was registered with the PROSPERO International Prospective Register of Systematic Reviews (CRD42023450249). Methodological quality was evaluated using the Modified Coleman Methodology Score. Odds ratios (ORs) and mean differences (MDs) quantified dichotomous and continuous outcomes, respectively. Results: Five articles, involving 405 knees, underwent analysis. Four studies were level 3 evidence, while 1 was level 1. The anteromedial hamstring harvest showed higher rates of saphenous nerve injury (OR, 9.77; 95% confidence interval [CI], 2.19-43.65; p = 0.003) and longer operative times, with an MD of about 13 minutes (MD, 13.33; 95% CI, 0.68-25.97; p = 0.04), compared to the posteromedial approach. The anteromedial method yielded a longer semitendinosus graft, with an MD of about 17 mm (MD, 17.57; 95% CI, 7.17-27.98; p = 0.0009). However, no significant differences existed in range of motion, flexion contracture, unintentional graft harvest, infection rates, and patient-reported outcomes. Notably, the posteromedial group reported higher cosmetic satisfaction, with 92% being very satisfied, compared to the anteromedial group with 80% (p = 0.005). However, overall satisfaction levels were similar between the 2 groups (p = 0.35), with a very satisfied rate of 72% for the anteromedial group and 78% for the posteromedial group. Conclusions: The anteromedial hamstring harvest showed greater saphenous nerve injury and longer operative times compared to the posteromedial approach, along with a longer graft. However, no significant differences were observed in the range of motion, flexion contracture, graft harvest, infection, or patient outcomes.

Effect of electrode attachment location for transcutaneous electrical nerve stimulation for pain relief in lumbar vertebral body fractures.

[Purpose] This study aimed to investigate the effect of the location of electrode attachment in transcutaneous electrical nerve stimulation on pain relief in patients with lumbar vertebral body fractures. [Participants and Methods] This study included 59 patients with lumbar vertebral body fractures, who were randomly assigned to receive transcutaneous electrical nerve stimulation to the lumbar region, lower limbs, or upper limbs, or no treatment, over a 4-week period. Pain, activities of daily living, and pain catastrophizing were assessed. [Results] Compared with the control group, transcutaneous electrical nerve stimulation to the lumbar region or lower limbs significantly reduced pain levels in the first 2 weeks. Although, activities of daily living and pain catastrophizing improved over time, no significant differences were observed between the groups. [Conclusion] Transcutaneous electrical nerve stimulation provides pain relief to patients during the early stages of lumbar vertebral body fractures. However, it had no effect on the activities of daily living, pain catastrophizing, or long-term pain-relief. For lumbar vertebral body fracture pain relief, transcutaneous electrical nerve stimulation electrodes should be attached to the lumbar region or lower limbs.

Reduction of Overactive Bladder Medications in Spinal Cord Injury With Self-Administered Neuromodulation; a Randomized Trial.

PURPOSE: To evaluate if self-administered bladder neuromodulation with transcutaneous tibial nerve stimulation can safely replace overactive bladder medications in people with spinal cord injury. MATERIALS AND METHODS: We performed a 3-month, randomized, investigator-blinded, tibial nerve stimulation vs sham-control trial in adults with spinal cord injury and neurogenic bladder performing intermittent catheterization and taking overactive bladder medications. The primary outcome was a reduction in bladder medications while maintaining stable bladder symptoms and quality of life based on pre-post Neurogenic Bladder Symptom Score and the Incontinence-QOL questionnaire, respectively. Secondary outcomes included changes in pre-post cystometrogram, 2-day voiding diaries, and an anticholinergic medication side effect survey. RESULTS: Fifty people consented to the study, with 42 completing the trial. No dropouts were due to stimulation issues. All baseline demographics and surveys were comparable at baseline. Cystometrogram parameters were also comparable at baseline, except the stimulation group had a higher proportion of loss of bladder compliance compared to the control group. At the end of the trial, a significantly greater percentage of the tibial nerve stimulation group were able to reduce medications (95% v 68%), by a 26.2% difference in medication reduction (95% confidence interval 1.17%-51.2%). Function and quality of life surveys and cystometrograms at the end of the trial were alike between groups. Transcutaneous tibial nerve stimulation satisfaction surveys and adherence to protocol were high. CONCLUSIONS: In people with chronic spinal cord injury performing intermittent catheterization, transcutaneous tibial nerve stimulation can be an option to reduce or replace overactive bladder medications.

Optic nerve elongation during fronto-facial surgery for Crouzon syndrome: 3D quantification and clinical implications.

OBJECTIVE: Fronto-facial monobloc advancement with internal distraction (FFMBA) is a key procedure in the management of syndromic craniosynostoses. FFMBA involves circumferential dissection and linear enlargement of the orbit, potentially leading to mechanical stress on the optic nerve (ON). Several reports of transient vision loss during the distraction process led us to investigate ON shape modifications during facial advancement, with the aim to potentially refine current clinical guidelines on postoperative management and the distraction schedule. METHODS: Twenty-six patients with Crouzon syndrome were included in this study. ONs were segmented on pre- and postoperative CT scans. Distraction amplitudes, linear and curved lengths, and cross-section diameters of the ON were assessed along the main axis of the nerve. A two-level hierarchical multivariate linear model was used to screen for factors associated with ON morphology. RESULTS: The mean age at FFMBA was 4.4 ± 3.8 years. Two patients presented with transient impaired vision during distraction. The final mean fronto-orbital and temporo-zygomatic distraction amplitudes were 18 ± 4 mm and 18 ± 6 mm, respectively. At the end of distraction, ONs were elongated (+1.8 mm for curved lengths, p = 0.013), and their mean cross-section was reduced (-1.9 mm2, p < 0.001) in the proximal intraorbital portion (first 15 mm). In the 2 patients with visual symptoms, functional impairment was associated with ON area reduction (OR 0.487, p < 0.001) and increased temporo-zygomatic distraction amplitude (OR 2.240, p < 0.001). CONCLUSIONS: ON was elongated during FFMBA, with proximal diameter reduction. Transient visual impairment with normal fundus examination during distraction seemed to have a morphological basis, based on 2 cases. These results suggest the importance of vision monitoring associated with fundus examination during distraction, and advocate for early extubation after FFMBA to allow clinical follow-up.

Extent of resection and progression-free survival in vestibular schwannoma: a volumetric analysis.

OBJECTIVE: To preserve facial nerve function in vestibular schwannoma (VS) microsurgery, some have advocated subtotal resection (STR) if the tumor is densely adherent to a thinned facial nerve. The objective of this study was to determine if residual volume is associated with progression and whether there is a threshold residual volume that should be pursued during STR to prevent recurrence. A secondary objective of this study was to determine whether facial nerve function at last follow-up was associated with extent of resection (EOR). METHODS: Clinical and radiographic data were retrospectively collected from the records of 164 patients with VS who underwent resection. Tumor volumes were measured using Visage, and standard statistical methods were used. The House-Brackmann scale was used to assess changes in facial nerve function before surgery and at last follow-up. RESULTS: Sixty-one patients (37%) received gross-total resection (GTR) and 103 (63%) received STR. The median clinical and radiographic follow-ups were 49 and 48 months, respectively. The median residual volume was 0.5 cm3 after STR. Kaplan-Meier actuarial survival analysis revealed a 96.3% 5-year progression-free survival (PFS) rate after GTR, which was greater than that after STR (84.5%, p = 0.03). Recursive partitioning analysis of patients receiving STR revealed a residual volume of 0.60 cm3 as the optimal threshold for recurrence. Patients with residual volume ≥ 0.60 cm3 had a 76.0% 5-year PFS, regardless of adjuvant SRS, which was lower than that for patients undergoing GTR (96.3%) or STR (95.6%) with residual volumes < 0.60 cm3 (p < 0.01). On Cox regression analysis, residual volume ≥ 0.60 cm3 (HR 14.4, p = 0.01) was independently associated with progression, even when accounting for patient age, adjuvant radiosurgery, and preoperative tumor size. In 112 patients with at least 24 months of follow-up after their last treatment, tumor control was achieved in 111 (99.1%) patients at a median last follow-up of 71 months. Worse facial nerve function at the last follow-up was independently associated with prior treatment for VS (adjusted OR 3.7, p = 0.04), but not residual volume cohort or preoperative tumor volume. CONCLUSIONS: Residual volume > 0.60 cm3 after VS resection was independently associated with tumor progression, even accounting for adjuvant SRS. These data support maximizing the EOR during VS surgery, even if GTR cannot be safely achieved.

Supinator to posterior interosseous nerve transfer to restore hand opening in brachial plexus and spinal cord injury: a systematic review and individual patient-data meta-analysis.

OBJECTIVE: Cervical spinal cord injury (SCI) and lower trunk brachial plexus injury (BPI) commonly result in hand paralysis. Although restoring hand function is complex and challenging to achieve, regaining volitional hand control drastically enhances functionality for these patients. The authors aimed to systematically review the outcomes of hand-opening function after supinator to posterior interosseous nerve (PIN) transfer. METHODS: A systematic literature review was performed according to the PRISMA guidelines. RESULTS: A total of 16 studies with 88 patients and 119 supinator to PIN transfers were included (87 transfers for SCI and 32 for BPI). In most studies, the time interval from injury to surgery was 6-12 months. Finger extension and thumb extension (Medical Research Council grade ≥ 3/5) recovered in 86.5% (103/119) and 78.1% (93/119) of cases, respectively, over a median follow-up of 19 months. The rates of recovery were similar for the SCI and BPI populations (finger extension, 87.3% in SCI and 84.3% in BPI; thumb extension, 75.8% in SCI and 84.3% in BPI). Type of injury (OR 1.05, 95% CI 0.17-6.4, p = 0.95), time from injury to surgery (OR 1.01, 95% CI 0.8-1.29, p = 0.88), and age (OR 0.97, 95% CI 0.90-1.06, p = 0.60) were not associated with odds of a successful outcome. Duration of follow-up was significantly associated with successful finger extension (OR 1.15, 95% CI 1.01-1.30, p = 0.026). No donor-associated supinator weakness was reported postoperatively given that patients had an intact bicep muscle preoperatively contributing to supination. CONCLUSIONS: Supinator to PIN transfer is a safe and effective procedure that can achieve successful restoration of digital extension in the SCI and BPI population at similar rates. Duration of follow-up was associated with superior outcomes, which was expected.

Renal autonomic dynamics in hypertension: how can we evaluate sympathetic activity for renal denervation?

This review explores the various pathophysiological factors influencing antihypertensive effects, involving the regulation of vascular resistance, plasma volume, cardiac function, and the autonomic nervous system, emphasizing the interconnected processes regulating blood pressure (BP). The kidney's pivotal role in BP control and its potential contribution to hypertension is complicated but important to understand the effective mechanisms of renal denervation (RDN), which may be a promising treatment for resistant hypertension. Excessive stimulation of the sympathetic nervous system or the renin-angiotensin-aldosterone system (RAAS) can elevate BP through various physiological changes, contributing to chronic hypertension. Renal sympathetic efferent nerve activation leads to elevated norepinephrine levels and subsequent cascading effects on vasoconstriction, renin release, and sodium reabsorption. RDN reduces BP in resistant hypertension by potentially disrupting sensory afferent nerves, decreasing feedback activation to the central nervous system, and reducing efferent sympathetic nerve activity in the heart and other structures. RDN may also modulate central sympathetic outflow and inhibit renal renin-angiotensin system overactivation. While evidence for RDN efficacy in hypertension is increasing, accurate patient selection becomes crucial, considering complex interactions that vary among patients. This review also discusses methods to evaluate autonomic nerve activity from the golden standard to new potential examination for finding out optimization in stimulation parameters or rigorous patient selection based on appropriate biomarkers.

Surgical and radiosurgical outcomes for Koos grade 3 vestibular schwannomas.

This study aimed to reveal the preferred initial treatment for Koos grade 3 vestibular schwannomas (VS). We performed a two-institutional retrospective study on 21 patients with Koos grade 3 VS undergoing resection at Yokohama Medical Center and 37 patients undergoing radiosurgery at Yokohama Rosai Hospital from 2010 to 2021. Tumor control, complications, and functional preservation were compared. The median pre-treatment volume and follow-up duration were 2845 mm3 and 57.0 months, respectively, in the resection group and 2127 mm3 and 81.7 months, respectively, in the radiosurgery group. In the resection group, 16 (76.2%) underwent gross total resection, and three patients (14.3%) experienced regrowth; however, no one required additional treatment. In the radiosurgery group, the tumor control rate was 86.5%, and three cases (8.1%) required surgical resection because of symptomatic brainstem compression. Kaplan-Meier analyses revealed that tumors with delayed continuous enlargement and large thin-walled cysts were significantly associated with poor prognostic factors (p = 0.0027, p < 0.001). The pre-radiosurgery growth rate was also associated with the volume increase (p = 0.013). Two cases (9.5%) required additional operation due to complications such as post-operative hematoma and cerebrospinal fluid leaks in the resection group, whereas temporary cranial neuropathies were observed in the radiosurgery group. Two patients (9.5%) had poor facial nerve function (House-Brackmann grading grade 3) in the resection group, while no one developed facial paresis in the radiosurgery group. Trigeminal neuropathy improved only in the resection group.Radiosurgery can be considered for the treatment of Koos grade 3 VS for functional preservation. However, resection may also be considered for patients with severe trigeminal neuropathy or a high risk of volume increments, such as large thin-walled cysts and rapid pre-treatment growth.

Variations of the extrapsoas course of the lumbar plexus with implications for the lateral transpsoas approach to the lumbar spine: a cadaveric study.

BACKGROUND: Together with an increased interest in minimally invasive lateral transpsoas approach to the lumbar spine goes a demand for detailed anatomical descriptions of the lumbar plexus. Although definitions of safe zones and essential descriptions of topographical anatomy have been presented in several studies, the existing literature expects standard appearance of the neural structures. Therefore, the aim of this study was to investigate the variability of the extrapsoas portion of the lumbar plexus in regard to the lateral transpsoas approach. METHODS: A total of 260 lumbar regions from embalmed cadavers were utilized in this study. The specimens were dissected as per protocol and all nerves from the lumbar plexus were morphologically evaluated. RESULTS: The most common variation of the iliohypogastric and ilioinguinal nerves was fusion of these two nerves (9.6%). Nearly in the half of the cases (48.1%) the genitofemoral nerve left the psoas major muscle already divided into the femoral and genital branches. The lateral femoral cutaneous nerve was the least variable one as it resembled its normal morphology in 95.0% of cases. Regarding the variant origins of the femoral nerve, there was a low formation outside the psoas major muscle in 3.8% of cases. The obturator nerve was not variable at its emergence point but frequently branched (40.4%) before entering the obturator canal. In addition to the proper femoral and obturator nerves, accessory nerves were present in 12.3% and 9.2% of cases, respectively. CONCLUSION: Nerves of the lumbar plexus frequently show atypical anatomy outside the psoas major muscle. The presented study provides a compendious information source of the possibly encountered neural variations during retroperitoneal access to different segments of the lumbar spine.

The ReInvigorate Study-phrenic nerve-to-diaphragm stimulation for weaning from mechanical ventilation: a protocol for a randomized pivotal clinical trial.

BACKGROUND: In the United States in 2017, there were an estimated 903,745 hospitalizations involving mechanical ventilation (MV). Complications from ventilation can result in longer hospital stays, increased risk of disability, and increased healthcare costs. It has been hypothesized that electrically pacing the diaphragm by phrenic nerve stimulation during mechanical ventilation may minimize or reverse diaphragm dysfunction, resulting in faster weaning. METHODS: The ReInvigorate Trial is a prospective, multicenter, randomized, controlled clinical trial evaluating the safety and efficacy of Stimdia's pdSTIM System for facilitating weaning from MV. The pdSTIM system employs percutaneously placed multipolar electrodes to stimulate the cervical phrenic nerves and activate contraction of the diaphragm bilaterally. Patients who were on mechanical ventilation for at least 96 h and who failed at least one weaning attempt were considered for enrollment in the study. The primary efficacy endpoint was the time to successful liberation from mechanical ventilation (treatment vs. control). Secondary endpoints will include the rapid shallow breathing index and other physiological and system characteristics. Safety will be summarized for both primary and additional analyses. All endpoints will be evaluated at 30 days or at the time of removal of mechanical ventilation, whichever is first. DISCUSSION: This pivotal study is being conducted under an investigational device exception with the U.S. Food and Drug Administration. The technology being studied could provide a first-of-kind therapy for difficult-to-wean patients on mechanical ventilation in an intensive care unit setting. TRIAL REGISTRATION: Clinicaltrials.gov, NCT05998018 , registered August 2023.