Timing of intraoperative neurophysiological monitoring (IONM) recovery and clinical recovery after termination of pediatric spinal deformity surgery due to loss of IONM signals.

BACKGROUND CONTEXT: Intraoperative neurophysiological monitoring (IONM) is used to reduce the risk of spinal cord injury during pediatric spinal deformity surgery. Significant reduction and/or loss of IONM signals without immediate recovery may lead the surgeon to acutely abort the case. The timing of when monitorable signals return remains largely unknown. PURPOSE: The goal of this study was to investigate the correlation between IONM signal loss, clinical examination, and subsequent normalization of IONM signals after aborted pediatric spinal deformity surgery to help determine when it is safe to return to the operating room. STUDY DESIGN/SETTING: This is a multicenter, multidisciplinary, retrospective study of pediatric patients (<18 years old) undergoing spinal deformity surgery whose surgery was aborted due to a significant reduction or loss of IONM potentials. PATIENT SAMPLE: Sixty-six patients less than 18 years old who underwent spinal deformity surgery that was aborted due to IONM signal loss were enrolled into the study. OUTCOME MEASURES: IONM data, operative reports, and clinical examinations were investigated to determine the relationship between IONM loss, clinical examination, recovery of IONM signals, and clinical outcome. METHODS: Information regarding patient demographics, deformity type, clinical history, neurologic and ambulation status, operative details, IONM information (eg, quality of loss [SSEPs, MEPs], laterality, any recovery of signals, etc.), intraoperative wake-up test, postoperative neurologic exam, postoperative imaging, and time to return to the operating were all collected. All factors were analyzed and compared with univariate and multivariate analysis using appropriate statistical analysis. RESULTS: Sixty-six patients were enrolled with a median age of 13 years [IQR 11-14], and the most common sex was female (42/66, 63.6%). Most patients had idiopathic scoliosis (33/66, 50%). The most common causes of IONM loss were screw placement (27/66, 40.9%) followed by rod correction (19/66, 28.8%). All patients had either complete bilateral (39/66, 59.0%), partial bilateral (10/66, 15.2%) or unilateral (17/66, 25.8%) MEP loss leading to termination of the case. Overall, when patients were returned to the operating room 2 weeks postoperatively, nearly 75% (40/55) had monitorable IONM signals. Univariate analysis demonstrated that bilateral SSEP loss (p=.019), bilateral SSEP and MEP loss (p=.022) and delayed clinical neurologic recovery (p=.008) were significantly associated with having unmonitorable IONM signals at repeat surgery. Multivariate regression analysis demonstrated that delayed clinical neurologic recovery (> 72 hours) was significantly associated with unmonitorable IONM signals when returned to the operating room (p=.006). All patients ultimately made a full neurologic recovery. CONCLUSIONS: In children whose spinal deformity surgery was aborted due to intraoperative IONM loss, there was a strong correlation between combined intraoperative SSEP/MEP loss, the magnitude of IONM loss, the timing of clinical recovery, and the time of electrophysiological IONM recovery. The highest likelihood of having a prolonged postoperative neurological deficit and undetectable IONM signals upon return to the OR occurs with bilateral complete loss of SSEPs and MEPs.

Awake intraoperative mapping for the prevention of amusia.

The authors describe the awake surgical mapping of music skills for patients who require resection in brain areas that may support musical abilities. A 65-year-old man was diagnosed with an anterolateral right temporal nonenhancing lesion, likely a diffusely infiltrating glioma, after presenting with several episodes of altered taste and smell and one episode of loss of consciousness. The patient specializes in music and music technology and has composed scores for films. An awake surgery was planned in a semiseated position. Prerecorded melodies were designed preoperatively as a surrogate for a composition skill task. These consisted of 10- to 15-second musical clips played during bipolar electrical stimulation of the overlying cortex and were divided into three segments: listen, play, and accuracy check. During the "listen" phase, the patient listened to a musical prompt. During the "play" phase, he played a musical response on a keyboard. Stimulation at multiple temporal neocortical sites was negative for any alteration in task performance. The patient did well postoperatively with excellent clinical and radiographic results and returned to composing music without functional compromise. Musical composition tasks can be performed safely intraoperatively for patients with musical expertise. Whether stimulating more posterior nondominant temporal neocortex or other cortical or white matter locations can disrupt this task remains undetermined.

Do Grip Strength Dynamometer Readings Improve After Cervical Spine Surgery?

STUDY DESIGN: Retrospective, cohort study. OBJECTIVES: Hand function can be difficult to objectively assess perioperatively. In patients undergoing cervical spine surgery by a single-surgeon, we sought to: (1) use a hand dynamometer to report pre/postoperative grip strength, (2) distinguish grip strength changes in patients with radiculopathy-only vs myelopathy, and (3) assess predictors of grip strength improvement. METHODS: Demographic and operative data were collected for patients who underwent surgery 2015-2018. Hand dynamometer readings were pre/postoperatively at three follow-up time periods (0-3 m, 3-6 m, 6-12 m). RESULTS: 262 patients (mean age of 59 ± 14 years; 37% female) underwent the following operations: ACDF (80%), corpectomy (25%), laminoplasty (19%), and posterior cervical fusion (7%), with 81 (31%) patients undergoing multiple operations in a single anesthetic setting. Radiculopathy-only was seen in 128 (49%) patients, and myelopathy was seen 134 (51%) patients. 110 (42%) had improved grip strength by ≥10-lbs, including 69/128 (54%) in the radiculopathy-only group, and 41/134 (31%) in the myelopathy group. Those most likely to improve grip strength were patients undergoing ACDF (OR 2.53, P = .005). Patients less likely to improve grip strength were older (OR = .97, P = .003) and underwent laminoplasty (OR = .44, 95% CI .23, .85, P = .014). Patients undergoing surgery at the C2/3-C5/6 levels and C6/7-T1/2 levels both experienced improvement during the 0-3-month time range (C2-5: P = .035, C6-T2: P = .015), but only lower cervical patients experienced improvement in the 3-6-month interval (P = .030). CONCLUSIONS: Grip strength significantly improved in 42% of patients. Patients with radiculopathy were more likely to improve than those with myelopathy. Patients undergoing surgery from the C2/3-C5/6 levels and the C6/7-T1/2 levels both significantly improved grip strength at 3-month postoperatively.

Monitoring risk and preventing ischemic stroke in the very old.

INTRODUCTION: Stroke is a significant cause of death, and the leading cause of severe long-term disability for individuals over 80 (the very old), yet few studies of such risk factors for ischemic stroke, or the known mitigation techniques, in this population, and the evidence base regarding risk modification strategies in this susceptible population can be inconsistent and incomplete. This article examines current guidelines and evidence regarding medical management, lifestyle changes, and psychosocial interactions that can contribute to the primary and secondary prevention of ischemic stroke in the very old. AREAS COVERED: The authors conducted a literature search for ischemic stroke prevention and risk assessment in the elderly via PubMed. Furthermore, they describe current strategies for monitoring risk and preventing ischemic stroke in the elderly population. EXPERT OPINION: Ischemic stroke poses a significant health risk to the elderly, with prevention relying on managing modifiable risk factors such as hypertension, atrial fibrillation, diabetes, and high cholesterol, as well as promoting healthy lifestyle choices like quitting smoking, regular physical activity and a heart-healthy diet. Healthcare providers must adopt a multifaceted approach, addressing individual and population-level factors while remaining vigilant in monitoring and managing risk factors to reduce the incidence and impact of stroke in older adults.

Role of gC1qR as a modulator of endothelial cell permeability and contributor to post-stroke inflammation and edema formation.

Ischemic stroke is a leading cause of death and disability worldwide. A serious risk of acute ischemic stroke (AIS) arises after the stroke event, due to inflammation and edema formation. Inflammation and edema in the brain are mediated by bradykinin, the formation of which is dependent upon a multi-ligand receptor protein called gC1qR. There are currently no preventive treatments for the secondary damage of AIS produced by inflammation and edema. This review aims to summarize recent research regarding the role of gC1qR in bradykinin formation, its role in inflammation and edema following ischemic injury, and potential therapeutic approaches to preventing post-stroke inflammation and edema formation.

Clinical Characteristics, Outcomes, and Pathology Analysis in Patients With Dorsal Arachnoid Web.

BACKGROUND: Dorsal arachnoid webs (DAWs) are rare pathological abnormalities of the arachnoid layer of the spinal cord that can result in pain and myelopathy. OBJECTIVE: To present clinical, imaging, and pathological characteristics of patients diagnosed with DAW, case illustrations, and a review of the literature. METHODS: Seventeen cases of DAW between 2015 and 2019 at a tertiary medical center were retrospectively identified through a case log search. Patient characteristics, preoperative imaging, operative notes, and pathology reports were collected. Our main outcome assessed was postoperative resolution of symptoms. Odds ratios were used to determine associations between preoperative signs and symptoms with postoperative symptom resolution. RESULTS: The mean age of the cohort was 50.5 years (IQR = 16) and presented primarily with back pain (64.7%). On imaging, all patients were found to have the "scalpel sign," and nearly half had a syrinx present (41.2%). All DAWs were located in the thoracic spine, with the most common location being the midthoracic (70.6%). The mean follow-up length for all patients was 4.3 months. There were no preoperative symptoms significantly associated with postoperative symptom resolution; however, a trend was noted with the presence of a preoperative syrinx. Pathology samples consistently demonstrated fibroconnective or collagenous tissue with no evidence of inflammation or neoplasm. CONCLUSION: DAW is a rare pathology that can result in myelopathy or inappropriate interventions if misdiagnosed. Surgical intervention using laminectomy with intradural exploration should be considered in symptomatic patients with DAW because it is curative with a strong chance of preoperative symptom resolution with relatively low complication rates.

A multicenter analysis of the prognostic value of histone H3 K27M mutation in adult high-grade spinal glioma.

OBJECTIVE: High-grade spinal glioma (HGSG) is a rare but aggressive tumor that occurs in both adults and children. Histone H3 K27M mutation correlates with poor prognosis in children with diffuse midline glioma. However, the role of H3 K27M mutation in the prognosis of adults with HGSG remains unclear owing to the rarity of this mutation, conflicting reports, and the absence of multicenter studies on this topic. METHODS: The authors studied a cohort of 30 adult patients with diffuse HGSG who underwent histological confirmation of diagnosis, surgical intervention, and treatment between January 2000 and July 2020 at six tertiary academic centers. The primary outcome was the effect of H3 K27M mutation status on progression-free survival (PFS) and overall survival (OS). RESULTS: Thirty patients (18 males and 12 females) with a median (range) age of 50.5 (19-76) years were included in the analysis. Eighteen patients had H3 K27M mutation-positive tumors, and 12 had H3 K27M mutation-negative tumors. The median (interquartile range) PFS was 3 (10) months, and the median (interquartile range) OS was 9 (23) months. The factors associated with increased survival were treatment with concurrent chemotherapy/radiation (p = 0.006 for PFS, and p ≤ 0.001 for OS) and American Spinal Injury Association grade C or better at presentation (p = 0.043 for PFS, and p < 0.001 for OS). There were no significant differences in outcomes based on tumor location, extent of resection, sex, or H3 K27M mutation status. Analysis restricted to HGSG containing necrosis and/or microvascular proliferation (WHO grade IV histological features) revealed increased OS for patients with H3 K27M mutation-positive tumors (p = 0.017). CONCLUSIONS: Although H3 K27M mutant-positive HGSG was associated with poor outcomes in adult patients, the outcomes of patients with H3 K27M mutant-positive HGSG were somewhat more favorable compared with those of their H3 K27M mutant-negative HGSG counterparts. Further preclinical animal studies and larger clinical studies are needed to further understand the age-dependent effects of H3 K27M mutation.

Pharmacological management of cerebral ischemia in the elderly.

Introduction: For elderly adults in the United States, stroke is the fifth leading cause of death of which ischemic strokes comprise a vast majority. Optimal pharmacological management of elderly ischemic stroke patients involves both reperfusion and supportive care. Recent research into pharmacological management has focused on vascular, immunomodulatory, cytoprotective, and alternative agents, some of which have shown limited success in clinical trials. However, no treatments have been established as a reliable mode for management of cerebral ischemia for elderly adults beyond acute thrombolysis.Areas covered: The authors conducted a literature search for ischemic stroke management in the elderly and a search for human drug studies for managing ischemic stroke on clinicaltrials.gov. Here, they describe recent progress in the pharmacological management of cerebral ischemia in the elderly.Expert opinion: Many drug classes (antihypertensive, cytoprotective and immunomodulatory, and alternative agents) have been explored with limited success in managing ischemic stroke, though some have shown preventative benefits. We generally observed a broad gap in evidence on elderly patients from studies across all drug classes, necessitating further studies to gain an understanding of effective management of ischemic stroke in this large demographic of patients.

Predicting Chronic Subdural Hematoma Resolution and Time to Resolution Following Surgical Evacuation.

Background: Growing evidence suggests that chronic subdural hematoma (CSDH) may have long-term adverse effects even after surgical evacuation. Hematoma recurrence is commonly reported as a short-term, postoperative outcome measure for CSDH, but other measures such as hematoma resolution may provide better insight regarding mechanisms behind longer-term sequelae. This study aims to characterize postoperative resolution times and identify predictors for this relatively unexplored metric. Methods: Consecutive cases (N = 122) of burr hole evacuation for CSDH by a single neurosurgeon at Columbia University Irving Medical Center from 2000 to 2019 were retrospectively identified. Patient characteristics, presenting factors, and date of hematoma resolution were abstracted from the electronic health record. Outcome measures included CSDH resolution at 6 months, surgery-to-resolution time, and inpatient mortality. Univariate and multivariate analyses were performed to determine predictors of outcome measures. Results: Hematoma resolution at 6 months was observed in 58 patients (47.5%), and median surgery-to-resolution time was 161 days (IQR: 85-367). Heavy drinking was predictive of non-resolution at 6 months and longer surgery-to-resolution time, while increased age was predictive of non-resolution at 6 months. Antiplatelet agent resumption was associated with non-resolution at 6 months and longer surgery-to-resolution time on univariate analysis but was not significant on multivariate analysis. Conclusion: Postoperative resolution times for most CSDHs are on the order of several months to a year, and delayed resolution is linked to heavy drinking and advanced age. Subsequent prospective studies are needed to directly assess the utility of hematoma resolution as a potential metric for long-term functional and cognitive outcomes of CSDH.

Downregulation of Bit1 expression promotes growth, anoikis resistance, and transformation of immortalized human bronchial epithelial cells via Erk activation-dependent suppression of E-cadherin.

The mitochondrial Bit1 protein exerts tumor-suppressive function in NSCLC through induction of anoikis and inhibition of EMT. Having this dual tumor suppressive effect, its downregulation in the established human lung adenocarcinoma A549 cell line resulted in potentiation of tumorigenicity and metastasis in vivo. However, the exact role of Bit1 in regulating malignant growth and transformation of human lung epithelial cells, which are origin of most forms of human lung cancers, has not been examined. To this end, we have downregulated the endogenous Bit1 expression in the immortalized non-tumorigenic human bronchial epithelial BEAS-2B cells. Knockdown of Bit1 enhanced the growth and anoikis insensitivity of BEAS-2B cells. In line with their acquired anoikis resistance, the Bit1 knockdown BEAS-2B cells exhibited enhanced anchorage-independent growth in vitro but failed to form tumors in vivo. The loss of Bit1-induced transformed phenotypes was in part attributable to the repression of E-cadherin expression since forced exogenous E-cadherin expression attenuated the malignant phenotypes of the Bit1 knockdown cells. Importantly, we show that the loss of Bit1 expression in BEAS-2B cells resulted in increased Erk activation, which functions upstream to promote TLE1-mediated transcriptional repression of E-cadherin. These collective findings indicate that loss of Bit1 expression contributes to the acquisition of malignant phenotype of human lung epithelial cells via Erk activation-induced suppression of E-cadherin expression.