Development and Internal Validation of the Postoperative Analgesic Intake Needs Score: A Predictive Model for Post-Operative Narcotic Requirement after Spine Surgery.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: The aim of this study was to develop a clinical tool to pre-operatively risk-stratify patients undergoing spine surgery based on their likelihood to have high postoperative analgesic requirements. METHODS: A total of 1199 consecutive patients undergoing elective spine surgery over a 2-year period at a single center were included. Patients not requiring inpatient admission, those who received epidural analgesia, those who had two surgeries at separate sites under one anesthesia event, and those with a length of stay greater than 10 days were excluded. The remaining 860 patients were divided into a derivation and validation cohort. Pre-operative factors were collected by review of the electronic medical record. Total postoperative inpatient opioid intake requirements were converted into morphine milligram equivalents to standardize postoperative analgesic requirements. RESULTS: The postoperative analgesic intake needs (PAIN) score was developed after the following predictor variables were identified: age, race, history of depression/anxiety, smoking status, active pre-operative benzodiazepine use and pre-operative opioid use, and surgical type. Patients were risk-stratified based on their score with the high-risk group being more likely to have high opioid consumption postoperatively compared to the moderate and low-risk groups in both the derivation and validation cohorts. CONCLUSION: The PAIN Score is a pre-operative clinical tool for patients undergoing spine surgery to risk stratify them based on their likelihood for high analgesic requirements. The information can be used to individualize a multi-modal analgesic regimen rather than utilizing a "one-size fits all" approach.

Percutaneous screw fixation versus open fusion for the treatment of traumatic thoracolumbar fractures: A retrospective case series of 185 Patients with a single-level spinal column injury.

STUDY DESIGN: Retrospective Single-Center Review of Data at a Level 1 Trauma Center. OBJECTIVE: Compare deformity correction and surgical outcomes of percutaneous instrumentation and open fusion in traumatic thoracolumbar fractures. METHODS: In our retrospective study, all patients undergoing elective spine surgery for TL fractures at a Level 1 trauma center between 2000 and 2017 were reviewed. Patients who underwent percutaneous fixation were given the option of hardware removal after the fracture had healed. RESULTS: A total of 185 patients were included in the study, with 109 treated with an open fusion, and 76 with percutaneous fixation. Twenty-five patients in the latter group had the instrumentation removed after the fracture had healed. None of them required reoperation. In the open fusion group 54.1% of patients required a decompressive laminectomy. Percutaneous fixation patients had a shorter operative time (98.3 min vs 214 min, p < 0.0001), shorter length of stay (9.8 days vs 13.5 days, p = 0.04), and less blood loss (68.4 cc vs 691 cc, p < 0.001). They also had a better correction of their traumatic kyphosis after surgery (p = 0.005). CONCLUSION: Percutaneous fixation is a valuable option for the treatment of TL fractures in cases without evidence of neural compression. It is still unclear whether hardware removal helps prevent adjacent segment degeneration. Percutaneous fixation could allow for better reduction of the fracture with improvement of postoperative alignment.

Microwave Ablation as a Treatment for Spinal Metastatic Tumors: A Systematic Review.

BACKGROUND: Microwave ablation (MWA) is a novel technique that offers several potential advantages over existing ablation systems, which include production of larger ablation zones, shorter procedural times, and more effective heating through high impedance tissues such as bone. METHODS: A systematic review was performed using inclusion criteria defined as follows: 1) metastatic spinal tumors treated with open or percutaneous MWA alone or in combination with other treatments, 2) available data on pain palliation and/or local tumor control, and 3) retrospective or prospective studies with at least 1 patient. RESULTS: A total of 156 patients harboring 196 spinal lesions underwent MWA in the 8 included studies. Most studies employed the use of additional interventions, which included minimally invasive open surgery with pedicle screw fixation, traditional open surgical intervention, and cement augmentation. Despite the variability in time intervals for pain assessment, postoperative pain scores decreased considerably in both percutaneous and open MWA studies. No evidence of tumor progression was additionally seen in >80% of patients at the last follow-up across 5 studies. Complications were reported in 6.5% of all patients who underwent percutaneous MWA and in 12.2% of patients who underwent open MWA. CONCLUSIONS: This review showed that MWA can be effective in achieving analgesia for up to 6 months in select cases, although most procedures were performed in combination with augmentation and/or open surgery. Local tumor control was additionally successful in most patients, suggestive of a potential curative role for MWA.

Extraneural metastatic anaplastic ependymoma: a systematic review and a report of metastases to bilateral parotid glands.

BACKGROUND: Anaplastic ependymoma with extraneural metastases is associated with a poor clinical outcome. Metastatic spread to the parotid gland is a rare clinical entity that requires multidisciplinary intervention. Herein, we present a systematic review of anaplastic ependymoma with extraneural metastases and report on a case with metastases to both parotid glands. METHODS: Electronic databases were searched from their inception to February 2019. Inclusion criteria included reports of anaplastic ependymoma with extraneural metastasis. Studies were excluded if the tumor grade was not reported. A case illustration is provided. RESULTS: The search yielded 15 cases of anaplastic ependymoma with extraneural metastases, including the present case. Mean age at diagnosis was 15 years. The initial tumor location was predominantly supratentorial (93.3%). All cases demonstrated leptomeningeal seeding before extraneural metastasis. Mean survival from initial diagnosis was 4.5 years. Metastasis to the parotid gland occurred in 2 cases, including the present case. We present a 17-year-old female patient who underwent gross total resection of a supratentorial, paraventricular anaplastic ependymoma followed by adjuvant external beam radiation therapy. The patient developed recurrent leptomeningeal seeding, treated with Gamma Knife radiosurgery over a 5-year period. She returned with a parotid mass and cervical lymphadenopathy and underwent parotidectomy and modified radical neck dissection. She continued to experience recurrences, including the left parotid gland, and was ultimately placed in hospice care. CONCLUSIONS: Anaplastic ependymoma with extraneural metastasis is rare. A combination of repeated surgical resection, radiation therapy, and chemotherapy can be used to manage recurrent and metastatic disease, but outcomes remain poor.

Tumoral Mimics of Subdural Hematomas: Case Report and Review of Diagnostic and Management Strategies in Primary B-Cell Lymphoma of the Subdural Space.

BACKGROUND: Subdural lymphomas are a rare subtype of primary central nervous system lymphomas that can radiographically mimic epidural blood and pose a diagnostic challenge. They can complicate treatment if not preemptively identified. METHODS: We present a case report of a subdural lymphoma that mimicked a compressive subdural hematoma, and we review the PubMed database for similar cases. RESULTS: A 77-year-old woman presented with a transient left facial droop and what appeared to be a subdural hematoma on computed tomography scan. The patient underwent surgery, during which grossly abnormal solid epicortical adherent tissue was noted instead of the expected appearance of a subdural hematoma. An intraoperative biopsy was suggestive of lymphoma, and the surgery was converted to a craniectomy. Pathology confirmed the diagnosis of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. The patient underwent radiotherapy with no complications or recurrence. Magnetic resonance imaging demonstrated complete resolution of the mass at 3 months after treatment, at which time the patient underwent a synthetic cranioplasty. Seven case reports of primary dural lymphomas mimicking subdural blood were found, with variable pathologic subclassifications. CONCLUSIONS: Although rare, a primary dural lymphoma can be mistaken for a subdural hematoma on computed tomography scan. The most common subtype is low-grade extranodal marginal zone lymphomas. It is important to keep these diseases in the differential diagnosis, especially when there is incongruence between imaging and the clinical picture, as earlier detection correlates to a stronger therapeutic response.

The Use of Prone Magnetic Resonance Imaging to Rule Out Tethered Cord in Patients With Structural Spine Anomalies: A Diagnostic Technical Note for Surgical Decision-making.

Tethered cord syndrome (TCS) is a clinical diagnosis that can be difficult to establish, as symptoms do not always match classic radiological findings, such as a low-lying conus. Surgery for spinal detethering is not without risk and does not always result in clinical improvement. Prone magnetic resonance imaging (MRI) has been described as a tool to assess the mobility of the spine. This is a technical imaging report where prone imaging was a factor that influenced the decision to defer surgery in favor of conservative management. T1 and T2 sagittal and T1 axial MRI imaging were obtained with the patient supine, and then repeated in the prone position. An anteroposterior conus movement of >10% of the canal width was considered normal. There was significant anterior movement of the conus when switching to the prone position. Surgery was deferred, and the patient improved after a regimen of intensive physical therapy. Prone MRI can be a useful tool to have in our neurosurgical armamentarium when assessing spinal cord tethering. Surgery is not recommended when normal anteroposterior movement of the conus is present.

Ventriculoperitoneal Shunt Outcomes of Normal Pressure Hydrocephalus: A Case Series of 116 Patients.

Background Permanent cerebrospinal fluid (CSF) diversion with a ventriculoperitoneal shunt (VPS) is a treatment option for patients with normal pressure hydrocephalus (NPH). Objectives Herein, we examine the outcomes, complication rates, and associations between predictors and outcomes after VPS in patients with NPH. Methods This was a retrospective review of 116 patients (68 males, 48 females) with NPH who underwent VPS placement from March 2008 to September 2017 after demonstrating objective and/or subjective improvement after a lumbar drain trial. The Chi-square test of independence was used to examine associations between predictors and clinical improvement after shunting. Complications associated with the VPS procedure were recorded. Results The mean age was 77 years (range 52-93). The mean duration of disturbance in gait, cognition, and continence were 29, 32, and 28 months, respectively. Of the 116 patients, 111 followed up at two weeks; of these, improvement in gait, incontinence, and cognition were reported in 72, 20, and 23 patients, respectively. Gait improved more than incontinence or cognition. A shorter duration of gait disturbance predicted an improvement in gait after shunting (p<0.01). Being on a cognition-enhancing medication predicted an improvement in cognition and/or incontinence after shunting (p<0.05). Complications included misplaced proximal catheters (n=6), asymptomatic catheter tract hemorrhages (n=3), bilateral hygromas (n=7), subdural hematomas (SDH) (n=5), and CSF leak (n=1). Conclusion VPS placement in patients with NPH is well-tolerated and associated with improved outcomes at least in the short-term follow-up (<6 months). A shorter duration of gait disturbance and being on a cognition-enhancing medication are associated with greater improvement after VPS.

Oculomotor Schwannomas: A Systematic Review and Report of Two Pediatric Cases Treated with Fractionated Cyberknife Stereotactic Radiotherapy.

OBJECTIVE: Pediatric oculomotor nerve schwannomas are rare and challenging lesions due to the high morbidity associated with surgical intervention and their proximity to critical structures limiting the opportunity for stereotactic radiosurgery. We aim to report and review the novel use of fractionated Cyberknife (Accuray, Inc., Sunnyvale, California, USA) stereotactic radiotherapy in pediatric patients with oculomotor schwannomas. METHODS: A systematic review of PubMed, Embase, and Cochrane was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two patients, ages 8 and 10 years, with tumor volumes of 0.1 cm3 and 0.2 cm3, respectively, were treated with fractionated Cyberknife radiotherapy at our institution. A total dose of 45-50 Gy was administered over 25 fractions (1.8-2.0 Gy per fraction) to the 82%-84% isodose line. Serial magnetic resonance imaging was obtained for long-term follow-up (56-58 months). RESULTS: We found 14 articles published between 1982 and 2018 that reported a total of 18 pediatric patients with intracranial oculomotor schwannomas. No previously described cases of pediatric intracranial oculomotor schwannomas were treated with radiation therapy. In both of our patients, radiographic tumor control was achieved at a mean follow-up of 57 months, with 1 patient displaying a decrease in tumor volume. Neither patient exhibited any worsening of their presenting symptoms, nor did either patient develop any new neurocognitive deficits following treatment. CONCLUSIONS: Fractionated Cyberknife radiotherapy is an effective and well-tolerated treatment option for intracranial oculomotor nerve schwannomas with excellent tumor control rates, similar to surgical and radiosurgical techniques, while sparing critical surrounding structures.

Clinical outcomes of normal pressure hydrocephalus in 116 patients: objective versus subjective assessment.

OBJECTIVE: Objective assessment tests are commonly used to predict the response to ventriculoperitoneal (VP) shunting in patients with normal pressure hydrocephalus (NPH). Whether subjective reports of improvement after a lumbar drain (LD) trial can predict response to VP shunting remains controversial. The goal in this study was to compare clinical characteristics, complication rates, and shunt outcomes of objective and subjective LD responders who underwent VP shunt placement. METHODS: This was a retrospective review of patients with NPH who underwent VP shunt placement after clinical improvement with the LD trial. Patients who responded after the LD trial were subclassified into objective LD responders and subjective LD responders. Clinical characteristics, complication rates, and shunt outcomes between the 2 groups were compared with chi-square test of independence and t-test. RESULTS: A total of 116 patients received a VP shunt; 75 were objective LD responders and 41 were subjective LD responders. There was no statistically significant difference in patient characteristics between the 2 groups, except for a shorter length of stay after LD trial seen with subjective responders. The complication rates after LD trial and VP shunting were not significantly different between the 2 groups. Similarly, there was no significant difference in shunt response between objective and subjective LD responders. The mean duration of follow-up was 1.73 years. CONCLUSIONS: Reports of subjective improvement after LD trial in patients with NPH can be a reliable predictor of shunt response. The currently used objective assessment scales may not be sensitive enough to detect subtle changes in symptomatology after LD trial.

Embolization of brain arteriovenous malformations with intent to cure: a systematic review.

OBJECTIVE: Endovascular embolization has been established as an adjuvant treatment strategy for brain arteriovenous malformations (AVMs). A growing body of literature has discussed curative embolization for select lesions. The transition of endovascular embolization from an adjunctive to a definitive treatment modality remains controversial. Here, the authors reviewed the literature to assess the lesional characteristics, technical factors, and angiographic and clinical outcomes of endovascular embolization of AVMs with intent to cure. METHODS: Electronic databases-Ovid MEDLINE, Ovid Embase, and PubMed-were searched for studies in which there was evidence of AVMs treated using endovascular embolization with intent to cure. The primary outcomes of interest were angiographic obliteration immediately postembolization and at follow-up. The secondary outcomes of interest were complication rates. Descriptive statistics were used to calculate rates and means. RESULTS: Fifteen studies with 597 patients and 598 AVMs treated with intent-to-cure embolization were included in this analysis. Thirty-four percent of AVMs were Spetzler-Martin grade III. Complete obliteration immediately postembolization was reported in 58.3% of AVMs that had complete treatment and in 45.8% of AVMs in the entire patient cohort. The overall clinical complication rate was 24.1%. The most common complication was hemorrhage, occurring in 9.7% of patients. Procedure-related mortality was 1.5%. CONCLUSIONS: While endovascular embolization with intent to cure can be an option for select AVMs, the reported complication rates appear to be increased compared with those in studies in which adjunctive embolization was the goal. Given the high complication rate related to a primary embolization approach, the risks and benefits of such a treatment strategy should be discussed among a multidisciplinary team. Curative embolization of AVMs should be considered an unanticipated benefit of such therapy rather than a goal.

Lumbar drain trial outcomes of normal pressure hydrocephalus: a single-center experience of 254 patients.

OBJECTIVE: A short-term lumbar drain (LD) trial is commonly used to assess the response of normal pressure hydrocephalus (NPH) patients to CSF diversion. However, it remains unknown whether the predictors of passing an LD trial match the predictors of improvement after ventriculoperitoneal shunting. The aim of this study was to examine outcomes, complication rates, and associations between predictors and outcomes after an LD trial in patients with NPH. METHODS: The authors retrospectively reviewed the records of 254 patients with probable NPH who underwent an LD trial between March 2008 and September 2017. Multivariate regression models were constructed to examine predictors of passing the LD trial. Complications associated with the LD trial procedure were recorded. RESULTS: The mean patient age was 77 years and 56.7% were male. The mean durations of gait disturbance, cognitive decline, and urinary incontinence were 29 months, 32 months, and 28 months, respectively. Of the 254 patients, 30% and 16% reported objective and subjective improvement after the LD trial, respectively. Complications included a sheared LD catheter, meningitis, lumbar epidural abscess, CSF leak at insertion site, transient lower extremity numbness, slurred speech, refractory headaches, and hyponatremia. Multivariate analyses using MAX-R revealed that a prior history of stroke predicted worse outcomes, while disproportionate subarachnoid spaces (uneven enlargement of supratentorial spaces) predicted better outcomes after the LD trial (r2 = 0.12, p < 0.05). CONCLUSIONS: The LD trial is generally safe and well tolerated. The best predictors of passing the LD trial include a negative history of stroke and having disproportionate subarachnoid spaces.

Detection of delayed cerebral ischemia using objective pupillometry in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Cerebral vasospasm causing delayed cerebral ischemia (DCI) is a source of significant morbidity after subarachnoid hemorrhage (SAH). Transcranial Doppler is used at most institutions to detect sonographic vasospasm but has poor positive predictive value for DCI. Automated assessment of the pupillary light reflex has been increasingly used as a reliable way of assessing pupillary reactivity, and the Neurological Pupil Index (NPi) has been shown to decrease hours prior to the clinical manifestation of ischemic injury or herniation syndromes. The aim of this study was to investigate the role of automated pupillometry in the setting of SAH, as a potential adjunct to TCD. METHODS: Our analysis included patients that had been diagnosed with aneurysmal SAH and admitted to the neuro-intensive care unit of the University of Texas Southwestern Medical Center between November 2015 and June 2017. A dynamic infrared pupillometer was used for all pupillary measurements. An NPi value ranging from 3 to 5 was considered normal, and from 0 to 2.9 abnormal. Sonographic vasospasm was defined as middle cerebral artery velocities greater than 100 cm/sec with a Lindegaard ratio greater than 3 on either side on transcranial Doppler. Most patients had multiple NPi readings daily and we retained the lowest value for our analysis. We aimed to study the association between DCI and sonographic vasospasm, and DCI and NPi readings. RESULTS: A total of 56 patients were included in the final analysis with 635 paired observations of daily TCD and NPi data. There was no statistically significant association between the NPi value and the presence of sonographic vasospasm. There was a significant association between DCI and sonographic vasospasm, χ2(1) = 6.4112, p = 0.0113, OR 1.6419 (95% CI 1.1163-2.4150), and between DCI and an abnormal decrease in NPi, χ2(1) = 38.4456, p < 0.001, OR 3.3930 (95% CI 2.2789-5.0517). Twelve patients experienced DCI, with 7 showing a decrease of their NPi to an abnormal range. This change occurred > 8 hours prior to the clinical decline 71.4% of the time. The NPi normalized in all patients after treatment of their vasospasm. CONCLUSIONS: Isolated sonographic vasospasm does not seem to correlate with NPi changes, as the latter likely reflects an ischemic neurological injury. NPi changes are strongly associated with the advent of DCI and could be an early herald of clinical deterioration.

Hypoglossal schwannomas: A systematic review of the literature.

BACKGROUND: Schwannomas of the hypoglossal nerve are rare and account for a very small percentage of non-vestibular schwannomas. OBJECTIVES: In this systematic review of the literature, we examined the epidemiology, symptomatology, management, and outcomes of patients with hypoglossal schwannomas. METHODS: The electronic database Pubmed was searched for all reports of hypoglossal schwannomas with descriptions of symptoms, management, and outcome characteristics. Data was extracted from each study and compiled in a spreadsheet. Continuous variables were reported as means and medians. Categorical variables were reported as proportions. Additional analysis was not done due to inconsistent reporting of outcomes and small sample sizes. RESULTS: A total of 59 studies (94 total individual cases) were included. 64% of patients were female with mean age of 44.6 years. The majority were intracranial/extracranial (50%). The most common symptoms were tongue deviation or speech disturbance (38%) and headaches (33%). Hypoglossal nerve dysfunction was present in 80% of patients. Surgical excision was performed in 93%, with a 15% complication rate. Evidence of residual mass after surgery was noted in 29%. Permanent hypoglossal nerve deficits occurred in 67%. Recurrence of tumor burden was reported in 6 studies, with median time to recurrence of 16.5 months. CONCLUSION: Current evidence suggests overall favorable outcomes with surgical resection of hypoglossal schwannomas, with a large percentage of patients experiencing mild and usually well-tolerated neurologic deficit. Limitations of this study include the use of retrospective data taken from case reports/series with highly selected patients, selective reporting, and absence of control groups.

Encephalopathy following melphalan administration.

OBJECTIVE: To describe a rare case of encephalopathy following melphalan administration. Presentation and intervention:: A 59-year-old female with multiple myeloma developed encephalopathy following administration of melphalan. After ruling out other aetiologies, we hypothesized elevated cytokines from systemic inflammatory response to melphalan as the likely aetiology. The TNF-alpha level was found to be significantly elevated. Plasmapharesis was performed which reduced the level of cytokines, and also improved the patient's neurological status. CONCLUSION: Melphalan administration, especially in renally impaired patients, may lead to development of encephalopathy. Based on our case report, we suggest that elevated levels of cytokines could be the underlying mechanism of worsening mental status.