Blockade of Gap Junction Hemichannel Suppresses Disease Progression in Mouse Models of Amyotrophic Lateral Sclerosis and Alzheimer's Disease

Glutamate released by activated microglia induces excitotoxic neuronal death, which likely contributes to non-cell autonomous neuronal death in neurodegenerative diseases, including amyotrophic lateral sclerosis and Alzheimer's disease. Although both blockade of glutamate receptors and inhibition of microglial activation are the therapeutic candidates for these neurodegenerative diseases, glutamate receptor blockers also perturbed physiological and essential glutamate signals, and inhibitors of microglial activation suppressed both neurotoxic/neuroprotective roles of microglia and hardly affected disease progression. We previously demonstrated that activated microglia release a large amount of glutamate specifically through gap junction hemichannel. Hence, blockade of gap junction hemichannel may be potentially beneficial in treatment of neurodegenerative diseases.In this study, we generated a novel blood-brain barrier permeable gap junction hemichannel blocker based on glycyrrhetinic acid. We found that pharmacologic blockade of gap junction hemichannel inhibited excessive glutamate release from activated microglia in vitro and in vivo without producing notable toxicity. Blocking gap junction hemichannel significantly suppressed neuronal loss of the spinal cord and extended survival in transgenic mice carrying human superoxide dismutase 1 with G93A or G37R mutation as an amyotrophic lateral sclerosis mouse model. Moreover, blockade of gap junction hemichannel also significantly improved memory impairments without altering amyloid β deposition in double transgenic mice expressing human amyloid precursor protein with K595N and M596L mutations and presenilin 1 with A264E mutation as an Alzheimer's disease mouse model.Our results suggest that gap junction hemichannel blockers may represent a new therapeutic strategy to target neurotoxic microglia specifically and prevent microglia-mediated neuronal death in various neurodegenerative diseases

Pediatric Stroke: A Review of Common Etiologies and Management Strategies

Pediatric stroke is an important cause of mortality and morbidity in children. There is a paucity of clinical trials pertaining to pediatric stroke management, and solidified universal guidelines are not established for children the way they are for the adult population. Diagnosis of pediatric stroke can be challenging, and it is often delayed or mischaracterized, which can result in worse outcomes. Understanding risks and appropriate therapy is paramount to improving care

Outcome and Prognostication After Cardiac Arrest

The outcome after out-of-hospital cardiac arrest has historically been grim at best. The current overall survival rate of patients admitted to a hospital is approximately 10%, making cardiac arrest one of the leading causes of death in the United States. The situation is improving with the incorporation of therapeutic temperature modulation, aggressive prevention of secondary brain injury, and improved access to advanced cardiovascular support, all of which have decreased mortality and allowed for better outcomes. Mortality after cardiac arrest is often the direct result of active withdrawal of life-sustaining therapy based on the perception that neurological recovery is not possible. This reality highlights the importance of providing accurate estimates of neurological prognosis to decision makers when discussing goals of care. The current standard of care for assessing neurological status in patients with hypoxic-ischemic encephalopathy emphasizes a multimodal approach that includes five elements: (1) neurological examination off sedation, (2) continuous electroencephalography, (3) serum neuron-specific enolase levels, (4) magnetic resonance brain imaging, and (5) somatosensory-evoked potential testing. Sophisticated decision support systems that can integrate these clinical, imaging, and biomarker and neurophysiologic data and translate it into meaningful projections of neurological outcome are urgently needed

The Effect of Frailty versus Initial Glasgow Coma Score in Predicting Outcomes Following Chronic Subdural Hemorrhage: A Preliminary Analysis

Background Initial Glasgow Coma Score (iGCS) is a well-known predictor of adverse outcomes following chronic subdural hemorrhage (cSDH). Frailty, i.e. a reduced physiologic reserve, is associated with poorer outcomes across the surgical literature, however, there is no consensus on the best measure of frailty. To date, no study has compared frailty\u27s ability to predict cSDH outcomes versus iGCS. The goal of this study was to, therefore, examine the prognostic value of the 5- (mFI-5) and 11-factor (mFI-11) modified frailty index, and Charlson Comorbidity Index (CCI) versus iGCS following cSDH. Methods Between January, 2016 and June, 2018, patients who presented to the emergency department with cSDH were retrospectively identified using the International Classification of Diseases (ICD) codes. mFI-5, mFI-11, and CCI scores were calculated using patient baseline characteristics. Primary endpoints were death and discharge home and subgroup analyses were performed among operative cSDH. Univariate and multivariate logistic regressions were used to determine predictors of primary endpoints. Results Of the 109 patients identified, the average age was 72.6±1.6 years and the majority (69/109, 63.3%) were male. The average CCI, mFI-5, and mFI-11 were 4.5 ±0.2, 1.5 ±0.1, and 2.2 ±0.1, respectively. Fifty (45.9%) patients required surgical intervention, 11 (10.1%) died, and 48 (43.4%) were discharged home. In the overall cohort, while the only multivariate predictor of mortality was iGCS (OR=0.58; 95%CI:0.44-0.77; p=0.0001), the CCI (OR=0.73; 95%CI:0.58-0.92; p=0.0082) was a superior predictor of discharge home compared to iGCS (OR=1.46; 95%CI:1.13-1.90; p=0.0041). Conversely, among those who received an operative intervention, the CCI, but not iGCS, independently predicted both mortality (OR=4.24; 95%CI:1.01-17.86; p=0.0491) and discharge home (OR=0.55; 95%CI:0.33-0.90; p=0.0170). Neither mFI nor age predicted primary outcomes in multivariate analysis. Conclusion While frailty is associated with worse surgical outcomes, the clinical utility of the mFI-5, mFI-11, and CCI in cSDH is unclear. We show that the iGCS is an overall superior predictor of mortality following cSDH but is outperformed by the CCI after operative intervention. Similarly, the CCI is the superior predictor of discharge home in cSDH patients overall and following an operative intervention. These results indicate that while the iGCS best predicts mortality overall, the CCI may be considered when prognosticating post-operative course and hospital disposition

The Effect of Frailty and Patient Comorbidities on Outcomes After Acute Subdural Hemorrhage: A Preliminary Analysis

BACKGROUND: Frailty is associated with worse outcomes across a variety of neurosurgical diseases. However, its effect on acute subdural hemorrhage (aSDH) outcomes is unclear. The goal of this study is to compare 3 measures of frailty with the gold standard (i.e., initial Glasgow Coma Scale [iGCS] score) for predicting outcomes after aSDH. METHODS: Patients who presented between January 2016 and June 2018 were retrospectively identified based on International Classification of Diseases codes for aSDH. Patients\u27 modified Frailty Index (mFI), temporalis muscle thickness (TMT), and age-adjusted Charlson Comorbidity Index (CCI) were calculated. Primary end points were death and discharge home. RESULTS: Of 167 patients included, the mean age was 63.4 ± 1.9 years, the average CCI was 3.4 ± 0.2, mFI was 1.4 ± 0.1, TMT was 7.1 ± 0.2 mm, and iGCS score was 11.9 ± 0.3. Sixty-nine patients (41.3%) were discharged home and 32 (19.2%) died during hospitalization. In multivariate analysis, decreasing iGCS score (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.74-0.96; P = 0.0112) and midline shift (OR, 1.27; 95% CI, 1.08-1.50; P = 0.0048), but not age or frailty, predicted mortality. In addition to iGCS score (OR, 1.26; 95% CI, 1.10-1.44; P = 0.0011), lower CCI (OR, 0.32; 95% CI, 0.14-0.74; P = 0.0071) and larger TMT (OR, 2.63; 95% CI, 1.16-5.99; P = 0.0210) independently predicted increased rates of discharge home. mFI was not independently associated with either primary end point in multivariate analysis. CONCLUSIONS: iGCS score predicts both mortality and discharge location after aSDH better than do age or frailty. However, CCI and TMT, but not mFI, are useful prognostic indicators of discharge to home after aSDH. The iGCS score should continue to be the primary prediction tool for patients with aSDH; however, frailty may be useful for resource allocation, especially when nearing discharge

Management and Outcomes of Adult Traumatic Cervical Spondyloptosis: A Case Report and Systematic Review

STUDY DESIGN: Systematic Review. OBJECTIVE: To elucidate treatment modalities and outcomes of patients with traumatic cervical spondyloptosis (TCS). SUMMARY: Traumatic cervical spondyloptosis (TCS) is rare and typically leads to devastating neurological injury. Management strategies vary from case to case. METHODS: A systematic review of the literature identified cases of adult TCS, and data was analyzed to characterize the patient population and to assess factors that influenced clinical outcome. In addition, an illustrative case is presented in which closed reduction of a severe C7-T1 spondyloptosis injury was guided with the use of cone beam computerized tomography (O-Arm) to overcome difficulties with visualizing the cervicothoracic junction region. RESULTS: In addition to our case, we identified 52 cases of adult TCS from 34 articles. Patient age ranged from 18 to 73 (average 45.6) with male a predominance (n = 37, 71.2%). Neurological function on presentation was most commonly ASIA E (34.6%), followed by ASIA D (21.2%) and ASIA A (19.2%). The most frequently affected levels were C7-T1 (44.2%) followed by C6-7 (33.0%). Closed reduction was attempted in 42 (80.8%) patients. A total of 49 (94.2%) patients underwent surgical treatment, with 31 (63.3%) undergoing single-approach procedures. The presence of neurological injury, cervical level of injury, and age were not significant predictors of successful closed reduction. Similarly, successful closed reduction, age, cervical level of injury, and neurological injury were not predictors of a single-approach treatment. CONCLUSION: TCS is rare and most frequently appears at or near the cervicothoracic junction and in males. The presentation is typically that of severe neurological injury, but partial neurological recovery occurs in many patients. No predictors of successful closed reduction or single approach surgery are identified. We postulate that the use of intraoperative multiplanar imaging technology like the O-Arm may enhance the ability to achieve a successful closed reduction given the predilection for the injury to occur at the cervicothoracic junction. Prospective study of the durability of constructs by single or combined approaches is warranted