OBJECTIVE: The objective of this paper was to compare the predictive ability of the recalibrated Risk Analysis Index (RAI-rev) with the 5-item modified frailty index-5 (mFI-5) for postoperative outcomes of anterior cervical discectomy and fusion (ACDF). METHODS: This study was performed using data of adult (age > 18 years) ACDF patients obtained from the National Surgical Quality Improvement Program database during the years 2015–2019. Multivariate modeling and receiver operating characteristic (ROC) curve analysis, including area under the curve/C-statistic calculation with the DeLong test, were performed to evaluate the comparative discriminative ability of the RAI-rev and mFI-5 for 5 postoperative outcomes. RESULTS: Both the RAI-rev and mFI-5 were independent predictors of increased postoperative mortality and morbidity in a cohort of 61,441 ACDF patients. In the ROC analysis for 30-day mortality prediction, C-statistics indicated a significantly better performance of the RAI-rev (C-statistic = 0.855, 95% CI 0.852–0.858) compared with the mFI-5 (C-statistic = 0.684, 95% CI 0.680–0.688) (p < 0.001, DeLong test). The results were similar for postoperative ACDF morbidity, Clavien-Dindo grade IV complications, nonhome discharge, and reoperation, demonstrating the superior discriminative ability of the RAI-rev compared with the mFI-5. CONCLUSIONS: The RAI-rev demonstrates superior discrimination to the mFI-5 in predicting postoperative ACDF mortality and morbidity. To the authors’ knowledge, this is the first study to document frailty as an independent risk factor for postoperative mortality after ACDF. The RAI-rev has conceptual fidelity to the frailty phenotype and may be more useful than the mFI-5 in preoperative ACDF risk stratification. Prospective validation of these findings is necessary, but patients with high RAI-rev scores may benefit from knowing that they might have an increased surgical risk for ACDF morbidity and mortality.

The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that functions via its discrete binding partners to form two multiprotein complexes, mTOR complex 1 and 2 (mTORC1 and mTORC2). Rapamycin-sensitive mTORC1, which regulates protein synthesis and cell growth, is tightly controlled by PI3K/Akt and is nutrient-/growth factor-sensitive. In the brain, mTORC1 is also sensitive to neurotransmitter signaling. mTORC2, which is modulated by growth factor signaling, is associated with ribosomes and is insensitive to rapamycin. mTOR regulates stem cell and cancer stem cell characteristics. Aberrant Akt/mTOR activation is involved in multistep tumorigenesis in a variety of cancers, thereby suggesting that the inhibition of mTOR may have therapeutic potential. Rapamycin and its analogues, known as rapalogues, suppress mTOR activity through an allosteric mechanism that only suppresses mTORC1, albeit incompletely. ATP-catalytic binding site inhibitors are designed to inhibit both complexes. This review describes the regulation of mTOR and the targeting of its complexes in the treatment of cancers, such as glioblastoma, and their stem cells.

BACKGROUND: Intracerebral hemorrhage (ICH) carries significant morbidity and mortality. Previous single-center retrospective analysis suggests that end-stage renal disease (ESRD) is a risk factor for severe ICH and worse outcomes. This investigation aims to examine the impact of ESRD on ICH severity, complications, and outcomes using a multicenter national database. METHODS: The International Classification of Disease, Ninth and Tenth Revision Clinical Modification codes were used to query the National Inpatient Sample for patients with ICH and ESRD between 2010 and 2019. Primary endpoints were the functional outcome, length of stay (LOS), and in-hospital mortality. Multivariate variable regression models and a propensity-score matched analysis were established to analyze patient outcomes associated with baseline patient characteristics. RESULTS: We identified 211,266 patients with ICH, and among them, 7,864 (3.77%) patients had a concurrent diagnosis of ESRD. Patients with ESRD were younger (60.85 vs. 67.64, P < 0.01) and demonstrated increased ICH severity (0.78 vs. 0.77, P < 0.01). ESRD patients experienced higher rates of sepsis (15.9% vs. 6.15%, P < 0.01), acute myocardial infarction (8.05% vs. 3.65%, P < 0.01), and cardiac arrest (5.94% vs. 2.4%, P < 0.01). In addition, ESRD predicted poor discharge disposition (odds ratio [OR]: 2.385, 95% confidence interval [CI]: 2.227–2.555, P < 0.01), longer hospital LOS (OR: 1.629, 95% CI: 1.553–1.709, P < 0.01), and in-hospital mortality (OR: 2.786, 95% CI: 2.647–2.932, P < 0.01). CONCLUSIONS: This study utilizes a multicenter database to analyze the effect of ESRD on ICH outcomes. ESRD is a significant predictor of poor functional outcomes, in-hospital mortality, and prolonged stay in the ICH population.

Kissing spines syndrome, also known as Baastrup’s disease, is a common yet underdiagnosed disorder involving close approximation of adjacent spinous processes. These painful pseudoarticulations may be secondary to the compensatory mechanisms that result from sagittal imbalance. Conventional operative correction of sagittal balance includes a wide range of procedures from facetectomies to vertebral column resection. Resection of kissing spines for the operative management of sagittal imbalance is a treatment modality not extensively discussed in the literature but may offer improved patient outcomes with shorter operative times, lower risk, and reduced length of stay. A 67-year old male with a history of degenerative disk disease and scoliosis presented with neurogenic claudication and severe back pain that worsened with walking and improved with sitting. X-ray imaging of the lumbar spine revealed straightening of the normal lumbar lordotic curvature with mild rotoscoliosis. There was also evidence of retrolisthesis of L2 on L3 that worsened with flexion. The patient had Baastrup’s disease at the L3-4 and L4, 5 levels that contributed to his reduced range of motion on extension imaging. Operative treatments including long-segment fusion with interbody cages to correct sagittal balance were considered with a discussion of possible debilitating and high-risk post-surgical outcomes. Instead, the patient underwent a simple decompression surgery involving laminectomies and resection of kissing spines to correct his sagittal imbalance. Postoperative follow-up imaging demonstrated significant improvement in sagittal balance, and the patient expressed relief of back and leg pain. Although underdiagnosed, consideration of kissing spines syndrome in the surgical correction of sagittal imbalance may offer an improvement over conventional operations. Our case presents a unique surgical perspective on the treatment of spinal stenosis with kissing spines with particular regard to correcting the sagittal imbalance, avoiding debilitating procedures, and providing better immediate postoperative outcomes.

To assess the impact of vagus nerve stimulation (VNS) on quality of life contributors such as rescue medications. Using the seizure diary application SeizureTracker™ database, we examined trends in rescue administration frequency before and after the first recorded VNS magnet swipe in patients with drug-resistant epilepsy who had 1) At least one VNS magnet swipe recorded in the diary, and 2) Recorded usage of a benzodiazepine rescue medication (RM) within 90 days prior to the first swipe. A paired Wilcoxon rank-sum test was used to assess changes in RM usage frequency between 30-, 60-, 90-, 180- and 360-day intervals beginning 30 days after first magnet swipe. Longitudinal changes in RM usage frequency were assessed with a generalized estimating equation model. We analyzed data of 95 patients who met the inclusion criteria. Median baseline seizure frequency was 8.3 seizures per month, with median baseline rescue medication usage frequency of 2.1 administrations per month (SD 3.3). Significant reductions in rescue medication usage were observed in the 91 to 180 day interval after first VNS magnet swipe, and at 181 to 360 days and at 361 to 720 days, with the magnitude of reduction increasing over time. Decreases in rescue medication usage were sustained when controlling for patients who did not record rescue medication use after the first VNS magnet swipe (N=91). Significant predictors of reductions in rescue medication included baseline frequency of rescue medication usage and time after first VNS magnet swipe. This retrospective analysis suggests that usage of rescue medications is reduced following the start of VNS treatment in patients with epilepsy, and that the magnitude of reduction may progressively increase over time.