Contemporaneous evaluation of patient experience, surgical strategy, and seizure outcomes in patients undergoing stereoelectroencephalography or subdural electrode monitoring.

OBJECTIVE: Intracranial electrographic localization of the seizure onset zone (SOZ) can guide surgical approaches for medically refractory epilepsy patients, especially when the presurgical workup is discordant or functional cortical mapping is required. Minimally invasive stereotactic placement of depth electrodes, stereoelectroencephalography (SEEG), has garnered increasing use, but limited data exist to evaluate its postoperative outcomes in the context of the contemporaneous availability of both SEEG and subdural electrode (SDE) monitoring. We aimed to assess the patient experience, surgical intervention, and seizure outcomes associated with these two epileptic focus mapping techniques during a period of rapid adoption of neuromodulatory and ablative epilepsy treatments. METHODS: We retrospectively reviewed 66 consecutive adult intracranial electrode monitoring cases at our institution between 2014 and 2017. Monitoring was performed with either SEEG (n = 47) or SDEs (n = 19). RESULTS: Both groups had high rates of SOZ identification (SEEG 91.5%, SDE 88.2%, P = .69). The majority of patients achieved Engel class I (SEEG 29.3%, SDE 35.3%) or II outcomes (SEEG 31.7%, SDE 29.4%) after epilepsy surgery, with no significant difference between groups (P = .79). SEEG patients reported lower median pain scores (P = .03) and required less narcotic pain medication (median = 94.5 vs 594.6 milligram morphine equivalents, P = .0003). Both groups had low rates of symptomatic hemorrhage (SEEG 0%, SDE 5.3%, P = .11). On multivariate logistic regression, undergoing resection or ablation (vs responsive neurostimulation/vagus nerve stimulation) was the only significant independent predictor of a favorable outcome (adjusted odds ratio = 25.4, 95% confidence interval = 3.48-185.7, P = .001). SIGNIFICANCE: Although both SEEG and SDE monitoring result in favorable seizure control, SEEG has the advantage of superior pain control, decreased narcotic usage, and lack of routine need for intensive care unit stay. Despite a heterogenous collection of epileptic semiologies, seizure outcome was associated with the therapeutic surgical modality and not the intracranial monitoring technique. The potential for an improved postoperative experience makes SEEG a promising method for intracranial electrode monitoring.

A survey of human brain transcriptome diversity at the single cell level.

The human brain is a tissue of vast complexity in terms of the cell types it comprises. Conventional approaches to classifying cell types in the human brain at single cell resolution have been limited to exploring relatively few markers and therefore have provided a limited molecular characterization of any given cell type. We used single cell RNA sequencing on 466 cells to capture the cellular complexity of the adult and fetal human brain at a whole transcriptome level. Healthy adult temporal lobe tissue was obtained during surgical procedures where otherwise normal tissue was removed to gain access to deeper hippocampal pathology in patients with medical refractory seizures. We were able to classify individual cells into all of the major neuronal, glial, and vascular cell types in the brain. We were able to divide neurons into individual communities and show that these communities preserve the categorization of interneuron subtypes that is typically observed with the use of classic interneuron markers. We then used single cell RNA sequencing on fetal human cortical neurons to identify genes that are differentially expressed between fetal and adult neurons and those genes that display an expression gradient that reflects the transition between replicating and quiescent fetal neuronal populations. Finally, we observed the expression of major histocompatibility complex type I genes in a subset of adult neurons, but not fetal neurons. The work presented here demonstrates the applicability of single cell RNA sequencing on the study of the adult human brain and constitutes a first step toward a comprehensive cellular atlas of the human brain.

Stanford University School of Medicine: Our Neurosurgical Heritage.

The legacy of Stanford University's Department of Neurosurgery began in 1858, with the establishment of a new medical school on the West Coast. Stanford Neurosurgery instilled an atmosphere of dedication to neurosurgical care, scientific research, education, and innovation. We highlight key historical events leading to the formation of the medical school and neurosurgical department, the individuals who shaped the department's vision and expansion, as well as pioneering advances in research and clinical care. The residency program was started in 1961, establishing the basis of the current education model with a strong emphasis on training future leaders, and the Moyamoya Center, founded in 1991, became the largest Moyamoya referral center in the United States. The opening of Stanford Stroke Center (1992) and seminal clinical trials resulted in a significant impact on cerebrovascular disease by expanding the treatment window of IV thrombolysis and intra-arterial thrombectomy. The invention and implementation of CyberKnife® (1994) marks another important event that revolutionized the field of radiosurgery, and the development of Stanford's innovative Brain Computer Interface program is pushing the boundaries of this specialty. The more recent launch of the Neurosurgery Virtual Reality and Simulation Center (2017) exemplifies how Stanford is continuing to evolve in this ever-changing field. The department also became a model for diversity within the school as well as nationwide. The growth of Stanford Neurosurgery from one of the youngest neurosurgery departments in the country to a prominent comprehensive neurosurgery center mirrors the history of neurosurgery itself: young, innovative, and willing to overcome challenges.

External validation of a predictive model of adverse events following spine surgery.

BACKGROUND CONTEXT: We lack models that reliably predict 30-day postoperative adverse events (AEs) following spine surgery. PURPOSE: We externally validated a previously developed predictive model for common 30-day adverse events (AEs) after spine surgery. STUDY DESIGN/SETTING: This prospective cohort study utilizes inpatient and outpatient data from a tertiary academic medical center. PATIENT SAMPLE: We assessed a prospective cohort of all 276 adult patients undergoing spine surgery in the Department of Neurosurgery at a tertiary academic institution between April 1, 2018 and October 31, 2018. No exclusion criteria were applied. OUTCOME MEASURES: Incidence of observed AEs was compared with predicted incidence of AEs. Fifteen assessed AEs included: pulmonary complications, congestive heart failure, neurological complications, pneumonia, cardiac dysrhythmia, renal failure, myocardial infarction, wound infection, pulmonary embolus, deep venous thrombosis, wound hematoma, other wound complication, urinary tract infection, delirium, and other infection. METHODS: Our group previously developed the Risk Assessment Tool for Adverse Events after Spine Surgery (RAT-Spine), a predictive model of AEs within 30 days following spine surgery using a cohort of approximately one million patients from combined Medicare and MarketScan databases. We applied RAT-Spine to the single academic institution prospective cohort by entering each patient's preoperative medical and demographic characteristics and surgical type. The model generated a patient-specific overall risk score ranging from 0 to 1 representing the probability of occurrence of any AE. The predicted risks are presented as absolute percent risk and divided into low (<17%), medium (17%-28%), and high (>28%). RESULTS: Among the 276 patients followed prospectively, 76 experienced at least one 30-day postoperative AE. Slightly more than half of the cohort were women (53.3%). The median age was slightly lower in the non-AE cohort (63 vs. 66.5 years old). Patients with Medicaid comprised 2.5% of the non-AE cohort and 6.6% of the AE cohort. Spinal fusion was performed in 59.1% of cases, which was comparable across cohorts. There was good agreement between the predicted AE and observed AE rates, Area Under the Curve (AUC) 0.64 (95% CI 0.56-0.710). The incidence of observed AEs in the prospective cohort was 17.8% among the low-risk group, 23.0% in the medium-risk group, and 38.4% in the high risk group (p =.003). CONCLUSIONS: We externally validated a model for postoperative AEs following spine surgery (RAT-Spine). The results are presented as low-, moderate-, and high-risk designations.

Intracranial Grade II Meningioma Oligometastatic to the Cervical Spine.

For intracranial meningiomas that metastasize extracranially, an oligometastatic state exists that is intermediate between incurable, widely metastatic disease and non-metastatic curable disease. Similar to oligometastatic cancer, aggressive local treatment of meningioma oligometastases is warranted, as it may be curable. We present a patient with multiply recurrent intracranial meningiomas over 19 years, with a transformation from grade I to grade II histology, with oligometastatic disease to the C5 vertebral body. Three years following definitive spinal stereotactic radiosurgery, she remains without evidence of other metastatic diseases. Our case highlights the oncologic concept that metastatic meningioma need not be widely disseminated and provides the clinical rationale for aggressive local treatment of an oligometastatic meningioma.

Outcomes of cervical laminoplasty-Population-level analysis of a national longitudinal database.

OBJECTIVE: Cervical laminoplasty is an important alternative to laminectomy in decompressing of the cervical spine. Further evidence to assess the utility of laminoplasty is required. We examine outcomes of cervical laminoplasty via a population level analysis in the United States. METHODS: We performed a population-level analysis using the national MarketScan longitudinal database to analyze outcomes and costs of cervical laminoplasty between 2007 and 2014. Outcomes included postoperative complications, revision rates, and functional outcomes. RESULTS: Using a national administrative database, we identified 2613 patients (65.6% male, mean 58.5 years) who underwent cervical laminoplasty. Mean length of stay was 3.1 ±â€¯2.8 days and mean follow-up was 795.5 ±â€¯670.6 days. The overall complication rate was 22.5% (N = 587), 30-day readmission rate was 7.5% (N = 195), and mortality rate was 0.08% (N = 2, elderly patients only). The complication rate was significantly increased in elderly patients (age >65 years) compared to non-elderly patients (OR 0.751, p < .01). The use of intraoperative neuromonitoring (IONM) during the cervical laminoplasty procedure did not significantly impact outcomes. The overall re-operation rate after the initial procedure was 10.9%. Total costs of cervical laminoplasty were mainly driven by hospital charges with physician-related payments comprising a small amount. CONCLUSIONS: Our national analysis of cervical laminoplasty found the procedure to be clinically effective with low complication rates and postoperative symptomatic improvement.

Primary paraspinal leiomyosarcoma invading the cervical spinal canal successfully treated with surgery, radiotherapy, and chemotherapy. Case report.

A primary paraspinal leiomyosarcoma invading the spine is an exceedingly rare neoplasm that may clinically mimic a schwannoma. The authors report a case involving a 45-year-old man with a primary leiomyosarcoma of the cervical paraspinal musculature that invaded the spinal canal at C1-2 and subsequently metastasized to the lungs and pancreas. Aggressive treatment consisting of resection of the primary tumor, adjunctive radiation therapy and chemotherapy, and surgical debulking of metastatic disease resulted in local tumor control at the primary site and long-term survival of the patient.

Cervical Osteochondroma Causing Myelopathy in Adults: Management Considerations and Literature Review.

BACKGROUND: Osteochondromas are the most frequent benign bone tumors but only rarely occur along the spinal column and even more rarely induce symptoms from spinal cord compression. CASE DESCRIPTIONS: We report 2 adult patients, both with a history of hereditary multiple exostoses, who presented with cervical myelopathy secondary to osteochondromas. The first patient is a 22-year-old man with numbness and weakness of his right upper limb and neck pain. Radiologic images showed a bony tumor arising from the C3 lamina with evidence of severe spinal cord compression. The second patient is a 20-year-old woman with weakness of her left upper and lower limbs and progressive numbness of the left hand, as well as neck and back pain. Radiologic images showed a bony tumor arising from the C4 lamina with evidence of significant spinal cord compression and cord signal abnormality. Both patients underwent surgical excision of the epidural mass and pathology confirmed a diagnosis of osteochondroma. CONCLUSIONS: We discuss the role of surgical intervention, management, and postoperative follow-up in adult patients with cervical osteochondromas. Recommended management includes radiographic imaging and surgical intervention, particularly when evidence of spinal cord impingement occurs. Consistent postoperative follow-up is necessary to ensure appropriate recovery of neurologic function. Surgical management of cervical osteochondromas typically results in excellent and stable clinical outcomes with rare recurrence.

Comparison of Porcine and Bovine Collagen Dural Substitutes in Posterior Fossa Decompression for Chiari I Malformation in Adults.

BACKGROUND: Posterior fossa decompression surgeries for Chiari malformations are susceptible to postoperative complications such as pseudomeningocele, external cerebrospinal fluid (CSF) leak, and meningitis. Various dural substitutes have been used to improve surgical outcomes. OBJECTIVE: This study examined whether the collagen matrix dural substitute type correlated with the incidence of postoperative complications after posterior fossa decompression in adult patients with Chiari I malformations. METHODS: A retrospective cohort study was conducted of 81 adult patients who underwent an elective decompressive surgery for treatment of symptomatic Chiari I malformations, with duraplasty involving a dural substitute derived from either bovine or porcine collagen matrix. Demographics and treatment characteristics were correlated with surgical outcomes. RESULTS: A total of 81 patients were included in the study. Compared with bovine dural substitute, porcine dural substitute was associated with a significantly higher risk of pseudomeningocele occurrence (odds ratio, 5.78; 95% confidence interval, 1.65-27.15; P = 0.01) and a higher overall complication rate (odds ratio, 3.70; 95% confidence interval, 1.23-12.71; P = 0.03) by univariate analysis. There was no significant difference in the rate of meningitis, repeat operations, or overall complication rate between the 2 dural substitutes. In addition, estimated blood loss was a significant risk factor for meningitis (P = 0.03). Multivariate analyses again showed that porcine dural substitute was associated with pseudomeningocele occurrence, although the association with higher overall complication rate did not reach significance. CONCLUSIONS: Dural substitutes generated from porcine collagen, compared with those from bovine collagen, were associated with a higher likelihood of pseudomeningocele development in adult patients undergoing Chiari I malformation decompression and duraplasty.

Purification and Characterization of Progenitor and Mature Human Astrocytes Reveals Transcriptional and Functional Differences with Mouse.

The functional and molecular similarities and distinctions between human and murine astrocytes are poorly understood. Here, we report the development of an immunopanning method to acutely purify astrocytes from fetal, juvenile, and adult human brains and to maintain these cells in serum-free cultures. We found that human astrocytes have abilities similar to those of murine astrocytes in promoting neuronal survival, inducing functional synapse formation, and engulfing synaptosomes. In contrast to existing observations in mice, we found that mature human astrocytes respond robustly to glutamate. Next, we performed RNA sequencing of healthy human astrocytes along with astrocytes from epileptic and tumor foci and compared these to human neurons, oligodendrocytes, microglia, and endothelial cells (available at http://www.brainrnaseq.org). With these profiles, we identified novel human-specific astrocyte genes and discovered a transcriptome-wide transformation between astrocyte precursor cells and mature post-mitotic astrocytes. These data represent some of the first cell-type-specific molecular profiles of the healthy and diseased human brain.

A giant cell tumor of the cranial base treated by stereotactic radiosurgery.

Giant cell tumors (GCTs) developing from the cranial bones are rare. Occurrence of these tumors in the vicinity of eloquent areas precludes complete excision. Fractionated external beam radiotherapy (FEBRT) has been used for those cases, but with inconsistent outcomes. The authors report a case of a patient with a GCT involving the left occiput which was successfully treated by CyberKnife stereotactic radiosurgery (CK RS). There was improvement in the neurological deficit and occipital pain without adjunctive treatment. This is the first report of stereotactic radiosurgery (SRS) adopted as a primary treatment modality for a cranial GCT.

Predictors of clinical and angiographic outcome after surgical or endovascular therapy of very large and giant intracranial aneurysms.

BACKGROUND: Risk factors for poor outcome in the treatment of very large (≥20-24 mm) and giant (≥25 mm) intracranial aneurysms remain incompletely defined. OBJECTIVE: To present an aggregate clinical series detailing a 24-year experience with very large and giant aneurysms to identify and assess the relative importance of various patient, aneurysm, and treatment-specific characteristics associated with clinical and angiographic outcomes. METHODS: The authors retrospectively identified 184 aneurysms measuring 20 mm or larger (85 very large, 99 giant) treated at Stanford University Medical Center between 1984 and 2008. Clinical data including age, presentation, and modified Rankin Scale (mRS) score were recorded, along with aneurysm size, location, and morphology. Type of treatment was noted and clinical outcome measured using the mRS score at final follow-up. Angiographic outcomes were completely occluded, occluded with residual neck, partly obliterated, or patent with modified flow. RESULTS: After multivariate analysis, risk factors for poor clinical outcome included a baseline mRS score of 2 or higher (odds ratio [OR], 0.23; 95% confidence interval [CI]: 0.08-0.66; P = .01), aneurysm size of 25 mm or larger (OR, 3.32; 95% CI: 1.51-7.28; P < .01), and posterior circulation location (OR, 0.18; 95% CI: 0.07-0.43; P < .01). Risk factors for incomplete angiographic obliteration included fusiform morphology (OR, 0.25; 95% CI: 0.10-0.66; P < .01), posterior circulation location (OR, 0.33; 95% CI: 0.13-0.83; P = .02), and endovascular treatment (OR, 0.14; 95% CI: 0.06-0.32; P < .01). Patients with incompletely occluded aneurysms experienced higher rates of posttreatment subarachnoid hemorrhage and had increased mortality compared with those with completely obliterated aneurysms. CONCLUSION: Our results suggest that patients with poor baseline functional status, giant aneurysms, and aneurysms in the posterior circulation had a significantly higher proportion of poor outcomes at final follow-up. Fusiform morphology, posterior circulation location, and endovascular treatment were risk factors for incompletely obliterated aneurysms.

Episodic encephalopathy due to an occult spinal vascular malformation complicated by superficial siderosis.

Superficial siderosis (SS) of the central nervous system is a rare condition caused by chronic subarachnoid hemorrhage. Clinical manifestations typically include sensorineural hearing loss and cerebellar ataxia. Recurrent episodic encephalopathy in the setting of SS has not been reported. We describe a unique case of SS in a 67-year-old man with an 8-year history of episodic encephalopathy associated with headache and vomiting. The patient also had a history of progressive dementia, ataxia, and myelopathy. A diagnosis of superficial siderosis was made after magnetic resonance gradient-echo images showed diffuse hemosiderin staining over the cerebellum and cerebral convexities. No intracerebral source of hemorrhage was identified. The patient therefore underwent gadolinium-enhanced spinal MRI which suggested a possible vascular malformation. A therapeutic laminectomy subsequently confirmed an arteriovenous fistula which was resected. In SS, there are often long delays between symptom onset and definitive diagnosis. Early identification is facilitated by magnetic resonance imaging with gradient-echo sequences. When no source of hemorrhage is identified intracranially, then total spinal cord imaging is indicated to assess for an occult source of hemorrhage as occurred in our case.

Comparison of endovascular and surface cooling during unruptured cerebral aneurysm repair.

OBJECTIVE: To compare endovascular versus surface methods for the induction and reversal of hypothermia during neurosurgery in a multicenter, prospective, randomized study. METHODS: Patients undergoing elective open craniotomy for repair of an unruptured cerebral aneurysm (n = 153) were randomly assigned (2:1) to undergo whole-body hypothermia to 33 degrees C, either with an endovascular cooling device placed in the inferior vena cava via the femoral vein (n = 92) or with a surface convective air blanket (n = 61). Active rewarming was accomplished using the same devices. RESULTS: Cooling rates in endovascular and surface blanket groups averaged 4.77 and 0.87 degrees C/h, respectively (P < 0.001). When the first temporary arterial or aneurysm clip was placed, 99% of endovascular patients and 20% of surface blanket patients had reached the target of 33 degrees C (P < 0.001). Obese patients were cooled efficiently with the endovascular approach (3.56 degrees C/h). Rewarming rates averaged 1.88 degrees C/h for endovascular patients and 0.69 degrees C/h for surface blanket patients (P < 0.001). By the end of surgery, 89 and 53% of these patients, respectively, had rewarmed to at least 35 degrees C (P < 0.001). On leaving the operating room, 14% of endovascular patients and 28% of surface blanket patients were still intubated (P = 0.035). The overall safety of the two procedures was comparable. No clinically significant catheter-related thrombotic, bleeding, or infectious complications were reported in the endovascular group. CONCLUSION: Endovascular cooling provided superior induction, maintenance, and reversal of hypothermia compared with the surface blanket, without an increase in complications. Endovascular cooling may have clinical benefit for patients undergoing cerebrovascular surgery, as well as patients with acute stroke, head injury, or acute myocardial infarction.