Cross-Sectional Analysis of US Health Insurance Payer Policies for Humanitarian Device Exemption Indications for Deep Brain Stimulation.

BACKGROUND: The US Food and Drug Administration (FDA) has granted deep brain stimulation (DBS) approval under the humanitarian device exemption (HDE) pathway for both dystonia and obsessive-compulsive disorder (OCD). However, recent reports from the community of functional neurosurgeons suggest that insurance authorization remains a disproportionate barrier to OCD DBS implantation despite both conditions having similar support from the FDA. This cross-sectional study of health insurance policies quantifies the current payer landscape for these two interventions. OBJECTIVES: The aim of this study was to quantify the current payer policy coverage of DBS under HDE status for OCD as compared to DBS for dystonia for eligible patients in the US insurance market. METHODS: A commercial health insurance policy database was queried for documentation on DBS for dystonia and OCD. Results were individually analyzed for payer policy coverage statements on DBS for either dystonia or OCD and categorized as unique or nonunique policies. Unique policy positions were then coded for the geographic region, whether coverage was offered, and guidelines cited as evidence and justification. RESULTS: From the 80 policies in the database, there were 34 unique policies addressing DBS for either dystonia or OCD representing coverage of all 50 states. Of the 34 unique policies, 3 (9%) covered DBS for OCD, while 32 (94%) covered dystonia. Only 2 policies covered neither intervention. CONCLUSIONS: In spite of similar levels of support from the FDA, DBS for OCD has less support from insurance companies on a national level. This study begins to quantify the disparity noted by functional neurosurgeons in recent literature.

Automated analysis of cortical volume loss predicts seizure outcomes after frontal lobectomy.

OBJECTIVE: Patients undergoing frontal lobectomy demonstrate lower seizure-freedom rates than patients undergoing temporal lobectomy and several other resective interventions. We attempted to utilize automated preoperative quantitative analysis of focal and global cortical volume loss to develop predictive volumetric indicators of seizure outcome after frontal lobectomy. METHODS: Ninety patients who underwent frontal lobectomy were stratified based on seizure freedom at a mean follow-up time of 3.5 (standard deviation [SD] 2.5) years. Automated quantitative analysis of cortical volume loss organized by distinct brain region and laterality was performed on preoperative T1-weighted magnetic resonance imaging (MRI) studies. Univariate statistical analysis was used to select potential predictors of seizure freedom. Backward variable selection and multivariate logistical regression were used to develop models to predict seizure freedom. RESULTS: Forty-eight of 90 (53.3%) patients were seizure-free at the last follow-up. Several frontal and extrafrontal brain regions demonstrated statistically significant differences in both volumetric cortical volume loss and volumetric asymmetry between the left and right sides in the seizure-free and non-seizure-free cohorts. A final multivariate logistic model utilizing only preoperative quantitative MRI data to predict seizure outcome was developed with a c-statistic of 0.846. Using both preoperative quantitative MRI data and previously validated clinical predictors of seizure outcomes, we developed a model with a c-statistic of 0.897. SIGNIFICANCE: This study demonstrates that preoperative cortical volume loss in both frontal and extrafrontal regions can be predictive of seizure outcome after frontal lobectomy, and models can be developed with excellent predictive capabilities using preoperative MRI data. Automated quantitative MRI analysis can be quickly and reliably performed in patients with frontal lobe epilepsy, and further studies may be developed for integration into preoperative risk stratification.

Small intracranial aneurysms in the Barrow Ruptured Aneurysm Trial (BRAT).

BACKGROUND: Treatment of small ruptured aneurysms (SRAs) remains controversial, with literature reporting difficulty with endovascular versus microsurgical approaches. This paper analyzes outcomes after endovascular coiling and microsurgical clipping among patients with SRAs prospectively enrolled in the Barrow Ruptured Aneurysm Trial (BRAT). METHOD: All BRAT patients were included in this study. Patient demographics, aneurysm size, aneurysm characteristics, procedure-related complications, and outcomes at discharge and at 1-year and 6-year follow-up were evaluated. A modified Rankin scale (mRS) score > 2 was considered a poor outcome. RESULTS: Of 73 patients with SRAs, 40 were initially randomly assigned to endovascular coiling and 33 to microsurgical clipping. The rate of treatment crossover was significantly different between coiling and clipping; 25 patients who were assigned to coiling crossed over to clipping, and no clipping patients crossed over to coiling (P < 0.001). Among SRA patients, 15 underwent coiling and 58 underwent clipping; groups did not differ significantly in demographic characteristics or aneurysm type (P ≥ 0.11). Mean aneurysm diameter was significantly greater in the endovascular group (3.0 ± 0.3 vs 2.6 ± 0.6; P = 0.02). The incidence of procedure-related complications was similar for endovascular and microsurgical treatments (odds ratio [95% confidence interval], 1.0 [0.1-10.0], P = 0.98). Both groups had comparable overall outcome (mRS score > 2) at discharge and 1-year and 6-year follow-up (P = 0.48 and 0.73, respectively). CONCLUSIONS: Most SRA patients in the BRAT underwent surgical clipping, with a high rate of crossover from endovascular approaches. Endovascular treatment was equivalent to surgical clipping with regard to procedure-related complications and neurologic outcomes.

Single-position prone lateral approach: cadaveric feasibility study and early clinical experience.

OBJECTIVE: Lateral lumbar interbody fusion (LLIF) is a useful minimally invasive technique for achieving anterior interbody fusion and preserving or restoring lumbar lordosis. However, achieving circumferential fusion via posterior instrumentation after an LLIF can be challenging, requiring either repositioning the patient or placing pedicle screws in the lateral position. Here, the authors explore an alternative single-position approach: LLIF in the prone lateral (PL) position. METHODS: A cadaveric feasibility study was performed using 2 human cadaveric specimens. A retrospective 2-center early clinical series was performed for patients who had undergone a minimally invasive lateral procedure in the prone position between August 2019 and March 2020. Case duration, retractor time, electrophysiological thresholds, implant size, screw accuracy, and complications were recorded. Early postoperative radiographic outcomes were reported. RESULTS: A PL LLIF was successfully performed in 2 cadavers without causing injury to a vessel or the bowel. No intraoperative subsidence was observed. In the clinical series, 12 patients underwent attempted PL surgery, although 1 case was converted to standard lateral positioning. Thus, 11 patients successfully underwent PL LLIF (89%) across 14 levels: L2-3 (2 of 14 [14%]), L3-4 (6 of 14 [43%]), and L4-5 (6 of 14 [43%]). For the 11 PL patients, the mean (± SD) age was 61 ± 16 years, mean BMI was 25.8 ± 4.8, and mean retractor time per level was 15 ± 6 minutes with the longest retractor time at L2-3 and the shortest at L4-5. No intraoperative subsidence was noted on routine postoperative imaging. CONCLUSIONS: Performing single-position lateral transpsoas interbody fusion with the patient prone is anatomically feasible, and in an early clinical experience, it appeared safe and reproducible. Prone positioning for a lateral approach presents an exciting opportunity for streamlining surgical access to the lumbar spine and facilitating more efficient surgical solutions with potential clinical and economic advantages.

Onyx embolization of skull base paragangliomas: a single-center experience.

BACKGROUND: Skull base paragangliomas are highly vascular tumors that are often embolized before surgical resection; however, the safety and efficacy of preoperative embolization using an ethylene vinyl alcohol copolymer (Onyx; Medtronic, Dublin, Republic of Ireland) in these tumors is unknown. This retrospective cohort study evaluated patient outcomes after preoperative embolization of skull base paragangliomas using Onyx. METHODS: We retrospectively analyzed data from all patients with skull base paragangliomas who underwent preoperative Onyx embolization at our institution (January 01, 2005-December 31, 2017). Patient, tumor, embolization, and outcomes data were extracted by reviewing inpatient and outpatient clinical and imaging records. RESULTS: Seven patients were studied (5/7 [71%] female), 6 with glomus jugulares and 1 with a glomus vagale. The median age was 52 years, and the most common presenting symptom was cranial neuropathy (6/7 [86%]). The tumor vascular supply was from the ascending pharyngeal artery in all 7 cases (100%) with additional feeders including the occipital artery in 5 (71%); internal carotid artery in 3 (43%); middle meningeal, vertebral, and internal maxillary artery each in 2 (29%); and posterior auricular artery in 1 (14%). The median postembolization tumor devascularization was 80% (range, 64-95%). The only postembolization complication was a facial palsy in 1 patient. CONCLUSION: Preoperative embolization with Onyx affords excellent devascularization for the majority of skull base paragangliomas, and it may facilitate resection of these hypervascular lesions. The advantages provided by Onyx with respect to penetration of intratumoral vessels must be weighed against the risk of cranial neuropathy.

Iatrogenic pseudoaneurysm rupture of the anterior cerebral artery after placement of an external ventricular drain, treated with clip-wrapping: a case report and review of the literature.

External ventricular drains (EVDs) are often placed emergently for patients with hydrocephalus, which carries a risk of hemorrhage. Rarely, rupture of a pseudoaneurysm originating from an EVD placement precipitates such a hemorrhage. An EVD was placed in a patient with a ruptured left posterior communicating artery aneurysm who later underwent endovascular coil embolization. On post-bleed day 20, a distal right anterior cerebral artery pseudoaneurysm along the EVD tract ruptured, which was successfully treated via clip-wrapping. Although EVD-associated pseudoaneurysms are rare, they have a high propensity for rupture. Early treatment of these lesions should be considered to prevent neurologic deterioration.

Association of Angiotensin-Converting Enzyme Inhibitors with Increased Mortality Among Patients with Isolated Severe Traumatic Brain Injury.

BACKGROUND: Traumatic brain injury (TBI) is associated with one-third of all deaths from trauma. Preinjury exposure to cardiovascular drugs may affect TBI outcomes. Angiotensin-converting enzyme inhibitors (ACEIs) exacerbate brain cell damage and worsen functional outcomes in the laboratory setting. ß-blockers (BBs), however, appear to be associated with reduced mortality among patients with isolated TBI. OBJECTIVE: Examine the association between preinjury ACEI and BB use and clinical outcome among patients with isolated TBI. METHODS: A retrospective cohort study of patients age ≥ 40 years admitted to an academic level 1 trauma center with isolated TBI between January 2010 and December 2014 was performed. Isolated TBI was defined as a head Abbreviated Injury Scale (AIS) score ≥ 3, with chest, abdomen, and extremity AIS scores ≤ 2. Preinjury medication use was determined through chart review. All patients with concurrent BB use were initially excluded. In-hospital mortality was the primary measured outcome. RESULTS: Over the 5-year study period, 600 patients were identified with isolated TBI who were naive to BB use. There was significantly higher mortality (P = .04) among patients who received ACEI before injury (10 of 96; 10%) than among those who did not (25 of 504; 5%). A multivariate stepwise logistic regression analysis revealed a threefold increased risk of mortality in the ACEI cohort (P < .001), which was even greater than the twofold increased risk of mortality associated with an Injury Severity Score ≥ 16. A second analysis that included patients who received preinjury BBs (n = 98) demonstrated slightly reduced mortality in the ACEI cohort with only a twofold increased risk in multivariate analysis (P = .05). CONCLUSIONS: Preinjury exposure to ACEIs is associated with an increase in mortality among patients with isolated TBI. This effect is ameliorated in patients who receive BBs, which provides evidence that this class of medications may provide a protective benefit.

Deep brain stimulation for appetite disorders: a review.

The mechanisms of appetite disorders, such as refractory obesity and anorexia nervosa, have been vigorously studied over the last century, and these studies have shown that the central nervous system has significant involvement with, and responsibility for, the pathology associated with these diseases. Because deep brain stimulation has been shown to be a safe, efficacious, and adjustable treatment modality for a variety of other neurological disorders, it has also been studied as a possible treatment for appetite disorders. In studies of refractory obesity in animal models, the ventromedial hypothalamus, the lateral hypothalamus, and the nucleus accumbens have all demonstrated elements of success as deep brain stimulation targets. Multiple targets for deep brain stimulation have been proposed for anorexia nervosa, with research predominantly focusing on the subcallosal cingulate, the nucleus accumbens, and the stria terminalis and medial forebrain bundle. Human deep brain stimulation studies that focus specifically on refractory obesity and anorexia nervosa have been performed but with limited numbers of patients. In these studies, the target for refractory obesity has been the lateral hypothalamus, ventromedial hypothalamus, and nucleus accumbens, and the target for anorexia nervosa has been the subcallosal cingulate. These studies have shown promising findings, but further research is needed to elucidate the long-term efficacy of deep brain stimulation for the treatment of appetite disorders.

Olfactory acuity in chronic migraine: a cross-sectional study.

OBJECTIVE/BACKGROUND: This study aims to measure olfactory acuity in chronic migraine subjects, at baseline and on migraine days, and compare to age- and sex-matched controls. Olfactory impairment is common in neurological disorders. While smell hypersensitivity has been established with chronic migraine, olfactory acuity has not been well studied. METHODS: We recruited 50 subjects with chronic migraine from the Jefferson Headache Center and 50 age- and sex-matched controls. Using the University of Pennsylvania Smell Identification Test (UPSIT), a validated test of olfaction, olfactory acuity was measured at baseline and during a migraine for subjects, and compared to controls at baseline and at home 2 weeks later. All subjects were additionally screened for odor sensitivity and allodynia. RESULTS: The mean UPSIT score for migraine subjects was 34.5 on non-migraine days and 34.7 on migraine days (mean difference=-0.4, 95% confidence interval [CI; -1.3, 0.6] P=.45). Controls had a mean of 35.9 and 36.1 for each test day (mean difference = -0.1, 95% CI [-0.9, 0.7] P=.87). On average, migraineurs performed worse than their matched control counterparts in both test sittings (test 1: P=.047; test 2: P=.01). The great majority of subjects were allodynic (42/50) compared with only 9 of 50 controls, and the majority of subjects (41/50) found more than one listed odor to be bothersome, compared with only 10/50 controls. On non-migraine days, 18/48 chronic migraine subjects had abnormal olfaction and on migraine days 14/42 had abnormal olfaction, compared with only 9/50 controls who had abnormal olfaction on their first UPSIT. CONCLUSIONS: While chronic migraine patients do not appear to have a significant change in olfactory acuity between migrainous and non-migrainous periods, they do appear to be more likely to have abnormal olfactory acuity at baseline compared to age- and sex-matched controls.

Post-operative antibiotic prophylaxis in spine surgery patients with thoracolumbar drains: A meta analysis.

Objective: Closed-suction drains are commonly placed after thoracolumbar surgery to reduce the risk of post-operative hematoma and neurologic deterioration, and may stay in place for a longer period of time if output remains high. Prolonged maintenance of surgical site drains, however, is associated with an increased risk of surgical site infection (SSI). The present study aims to examine the literature regarding extended duration (≥24 h) prophylactic antibiotic use in patients undergoing posterior thoracolumbar surgery with closed-suction drainage. Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Relevant studies reporting the use of 24-h post-operative antibiotics compared with extended duration post-operative antibiotics in patients undergoing posterior thoracolumbar surgery with closed-suction drainage were identified from a PubMed database query. Results: Six studies were included for statistical analysis, encompassing 1003 patients that received 24 h of post-operative antibiotics and 984 patients that received ≥24 h of post-operative antibiotics. The SSI rate was 5.16 % for the shorter duration group (24 h) and 4.44 % (p = 0.7865) for the longer duration group (≥24 h). Conclusions: There is no significant difference in rates of SSI in patients receiving 24 h of post-operative antibiotics compared with patients receiving ≥24 h of post-operative antibiotics. Shorter durations of post-operative antibiotics in patients with thoracolumbar drains have similar outcomes compared to patients receiving longer courses of antibiotics. Shorter durations of antibiotics could potentially help lead to lower overall cost and length of stay for these patients.

Stereoelectroencephalography in the setting of a previously implanted responsive neural stimulation device: illustrative case.

BACKGROUND: Responsive neural stimulation (RNS) is a relatively novel procedure for drug-resistant epilepsy, which involves implantation of a device into the skull and brain. As more devices are implanted, there may be an increasing need to perform intracranial electrocorticography in implant patients with persistent seizures. Given the device location, imaging difficulties with implanted devices, and other technical hurdles, stereoelectroencephalography (SEEG) could be especially challenging. The authors describe the first reported SEEG investigation in a patient with an RNS device, highlighting the technical challenges and clinical data ascertained. OBSERVATIONS: A 41-year-old male with drug-resistant epilepsy presented several years after a local surgeon had placed an RNS device with two electrodes in the bilateral parieto-occipital lobes. Because of inadequate seizure control, the patient was offered a repeat SEEG investigation to characterize his epilepsy better. Although more technically challenging than a traditional SEEG implantation, the SEEG investigation was successfully performed, which led to a confirmation of bilateral hippocampal seizure onset. The patient underwent repositioning of his RNS leads with a significant decrease in his seizure frequency. LESSONS: Concurrent implantation of SEEG electrodes in a functioning RNS device can be safely performed and can augment our understanding of a patient's seizures.

Systematic Review and Meta-Analysis of Responsive Neurostimulation in Epilepsy.

BACKGROUND: Neuromodulatory implants provide promising alternatives for patients with drug-resistant epilepsy (DRE) in whom resective or ablative surgery is not an option. Responsive neurostimulation (RNS) operates a unique "closed-loop" system of electrocorticography-triggered stimulation for seizure control. A comprehensive review of the current literature would be valuable to guide clinical decision-making regarding RNS. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocols, a systematic PubMed literature review was performed to identify appropriate studies involving patients undergoing RNS for DRE. Full texts of included studies were analyzed and extracted data regarding demographics, seizure reduction rate, responder rate (defined as patients with >50% seizure reduction), and complications were compiled for comprehensive statistical analysis. RESULTS: A total of 313 studies were screened, and 17 studies were included in the final review, representative of 541 patients. Mean seizure reduction rate was 68% (95% confidence interval 61%-76%), and the mean responder rate was 68% (95% confidence interval 60%-75%). Complications occurred in 102 of 541 patients, for a complication rate of 18.9%. A strong publication bias toward greater seizure reduction rate and increased responder rate was demonstrated among included literature. CONCLUSIONS: A meta-analysis of recent RNS for DRE literature demonstrates seizure reduction and responder rates comparable with other neuromodulatory implants for epilepsy, demonstrating both the value of this intervention and the need for further research to delineate the optimal patient populations. This analysis also demonstrates a strong publication bias toward positive primary outcomes, highlighting the limitations of current literature. Currently, RNS data are optimistic for the treatment of DRE but should be interpreted cautiously.

Robot-Assisted Stereoelectroencephalography: 2-Dimensional Operative Video.

Invasive neuromonitoring is an important component of presurgical workup and seizure onset zone localization in patients with epilepsy being considered for surgical resection. In the United States, intraparenchymal stereoelectroencephalography (SEEG) electrodes have been replacing subdural grid electrodes for most cases, following a trend that has already matured in Europe. The use of robotic assistance has been shown to improve operative times and accuracy in SEEG electrode placement, as users benefit from the embedded planning software as well as the efficiency and accuracy of the robotic arm. The greatest barriers to implementation of this technology are the upfront cost and learning curve. This case-based surgeon's perspective operative video could benefit those considering incorporating robotic assistance for SEEG electrode placement. Those considering robotic assistance for pedicle screw placement and other budding applications may also benefit, as well as innovators looking for new applications. The patient consented for the procedure, video recording, and inclusion in subsequent publications.

Anatomical Subpial Resection of Tumors in the Amygdala and Hippocampus.

OBJECTIVE: Surgical techniques to achieve complete resection of mesial-basal temporal tumors should be pursued by neurosurgical oncologists. We describe the anatomical subpial amygdalohippocampectomy (SpAH) technique for tumor resection. METHODS: The key anatomical landmarks and critical steps of the SpAH technique were outlined and emphasized with medical illustrations and intraoperative photographs. The senior author's 90-day surgical outcomes with this approach were reviewed. RESULTS: Twenty-five patients (men, 17 [68%]; women, 8 [32%]; median [range] age, 59 [23-80] years) with temporal tumors involving the amygdalohippocampal region were included. SpAH was performed selectively in 8 [32%] patients, whereas 17 [68%] patients underwent SpAH in conjunction with an anterior temporal lobectomy due to tumor involvement of the anterolateral temporal cortex. The subpial resection of the amygdala protected the critical structures of the suprasellar cistern and sylvian fissure. Identifying the choroidal fissure as the superior-most aspect of hippocampal resection protected the optic tract and the thalamus. Subpial resection of the parahippocampal gyrus inferiorly protected the brainstem and critical structures of the ambient cistern. Tumors in the amygdalohippocampal region were anatomically and completely resected in all 25 patients. Of the 15 patients who presented with seizures, 13 (87%) were seizure-free at the 90-day postsurgical follow-up. Permanent neurologic deficits occurred in 3 patients (12%). CONCLUSIONS: The SpAH technique permits complete resection of mesial-basal temporal tumors with an acceptable morbidity profile. An in-depth understanding of temporal lobe anatomy combined with a refined microsurgical technique allows for reproducible resection of tumor in the amygdalohippocampal region while protecting critical neurovascular structures.

Retrograde Suction Decompression for Clipping of a Giant Ophthalmic Internal Carotid Artery Aneurysm: 2-Dimensional Operative Video.

Microsurgical clipping of large paraclinoid aneurysms is challenging because of the complex anatomy of the dural rings, lack of easy proximal control, and wide aneurysm necks. Proximal retrograde suction decompression, or the Dallas technique, can reduce aneurysm turgor and, with aspiration of the trapped cervical and supraclinoid internal carotid arteries (ICAs), can collapse the aneurysm to aid microsurgical clipping.1-5 A woman in her late 30s presented with decreased right-eye visual acuity. Informed written consent was obtained for microsurgical management and publication. Upon cervical exposure of the carotid bifurcation, we performed a standard pterional craniotomy, trans-sylvian exposure, and intradural anterior clinoidectomy. After burst suppression and cross-clamping of the carotid, we inserted an angiocatheter at the common carotid artery (CCA). Distal temporary clips were placed on the posterior communicating artery and C7 ICA. With the cervical ICA unclamped, retrograde suction was continuously applied to deflate the aneurysm. We applied 2 pairs of fenestrated-booster clips to the aneurysm dome and a fifth clip to the aneurysm neck. After restoration of flow, indocyanine green angiography and Doppler assessments were performed. The proximal clip was converted into a curved clip to optimize ICA flow. Postoperative angiography confirmed complete occlusion of the aneurysm. The patient was discharged on postoperative day 3, with stable visual acuity.6 This video demonstrates that retrograde suction decompression via the cervical CCA can be safely performed to facilitate clipping of complex paraclinoid ICA aneurysms. Comprehensive planning of temporary aneurysm trapping for suction decompression and permanent clip construct for aneurysm occlusion are needed for effective aneurysm repair.

COVID-19 and Neurosurgery Consultation Call Volume at a Single Large Tertiary Center With a Propensity-Adjusted Analysis.

BACKGROUND: The COVID-19 pandemic has significantly affected patient care across specialties. Ramifications for neurosurgery include substantial disruptions to surgical training and changes in nonurgent patient presentations to the emergency department. This study quantifies the effects of the COVID-19 pandemic on the number of emergency department patients who were referred to the neurosurgery department for further consultation and treatment and identifies and describes trends in the characteristics of these visits. METHODS: A retrospective review was performed of neurosurgical consultations at a single high-volume institution for 28 call-day periods before and after the official announcement of the pandemic. Primary outcomes included consultations per call-day, patient presentation category, and patient admission. RESULTS: The neurosurgical service was consulted regarding 629 patients (367 male patients) during the study period, with 471 (75%) and 158 (25%) patients presenting before and after the announcement of the COVID-19 pandemic, respectively. The mean number of neurosurgical consultations per call-day was significantly lower in the COVID-19 period (5.6 consultations) compared with the pre-COVID-19 period (16.8 consultations) (P < 0.001). After adjusting for patient demographics, the rate of presentation for general nonurgent concerns, such as back pain, headaches, and other general weaknesses, significantly decreased (odds ratio [95% confidence interval], 0.60 [0.47-0.77], P < 0.001). CONCLUSIONS: Neurosurgical consultations significantly decreased after the onset of the COVID-19 pandemic, with a substantially lower overall number of consultations necessitating operative interventions. Furthermore, the relative number of patients with nonemergent neurological conditions significantly decreased during the pandemic.

Predictors of indirect neural decompression in minimally invasive transpsoas lateral lumbar interbody fusion.

OBJECTIVE: An advantage of lateral lumbar interbody fusion (LLIF) surgery is the indirect decompression of the neural elements that occurs because of the resulting disc height restoration, spinal realignment, and ligamentotaxis. The degree to which indirect decompression occurs varies; no method exists for effectively predicting which patients will respond. In this study, the authors identify preoperative predictive factors of indirect decompression of the central canal. METHODS: The authors performed a retrospective evaluation of prospectively collected consecutive patients at a single institution who were treated with LLIF without direct decompression. Preoperative and postoperative MRI was used to grade central canal stenosis, and 3D volumetric reconstructions were used to measure changes in the central canal area (CCA). Multivariate regression was used to identify predictive variables correlated with radiographic increases in the CCA and clinically successful improvement in visual analog scale (VAS) leg pain scores. RESULTS: One hundred seven levels were treated in 73 patients (mean age 68 years). The CCA increased 54% from a mean of 0.96 cm2 to a mean of 1.49 cm2 (p < 0.001). Increases in anterior disc height (74%), posterior disc height (81%), right (25%) and left (22%) foraminal heights, and right (12%) and left (15%) foraminal widths, and reduction of spondylolisthesis (67%) (all p < 0.001) were noted. Multivariate evaluation of predictive variables identified that preoperative spondylolisthesis (p < 0.001), reduced posterior disc height (p = 0.004), and lower body mass index (p = 0.042) were independently associated with radiographic increase in the CCA. Thirty-two patients were treated at a single level and had moderate or severe central stenosis preoperatively. Significant improvements in Oswestry Disability Index and VAS back and leg pain scores were seen in these patients (all p < 0.05). Twenty-five (78%) patients achieved the minimum clinically important difference in VAS leg pain scores, with only 2 (6%) patients requiring direct decompression postoperatively due to persistent symptoms and stenosis. Only increased anterior disc height was predictive of clinical failure to achieve the minimum clinically important difference. CONCLUSIONS: LLIF successfully achieves indirect decompression of the CCA, even in patients with substantial central stenosis. Low body mass index, preoperative spondylolisthesis, and disc height collapse appear to be most predictive of successful indirect decompression. Patients with preserved disc height but severe preoperative stenosis are at higher risk of failure to improve clinically.

An evaluation of the SAFIRE grading scale as a predictor of long-term outcomes for patients in the Barrow Ruptured Aneurysm Trial.

OBJECTIVE: The SAFIRE grading scale is a novel, computable scale that predicts the outcome of aneurysmal subarachnoid hemorrhage (aSAH) patients in acute follow-up. However, this scale also may have prognostic significance in long-term follow-up and help guide further management. METHODS: The records of all patients enrolled in the Barrow Ruptured Aneurysm Trial (BRAT) were retrospectively reviewed, and the patients were assigned SAFIRE grades. Outcomes at 1 year and 6 years post-aSAH were analyzed for each SAFIRE grade level, with a poor outcome defined as a modified Rankin Scale score > 2. Univariate analysis was performed for patients with a high SAFIRE grade (IV or V) for odds of poor outcome at the 1- and 6-year follow-ups. RESULTS: A total of 405 patients with confirmed aSAH enrolled in the BRAT were analyzed; 357 patients had 1-year follow-up, and 333 patients had 6-year follow-up data available. Generally, as the SAFIRE grade increased, so did the proportion of patients with poor outcomes. At the 1-year follow-up, 18% (17/93) of grade I patients, 22% (20/92) of grade II patients, 32% (26/80) of grade III patients, 43% (38/88) of grade IV patients, and 75% (3/4) of grade V patients were found to have poor outcomes. At the 6-year follow-up, 29% (23/79) of grade I patients, 24% (21/89) of grade II patients, 38% (29/77) of grade III patients, 60% (50/84) of grade IV patients, and 100% (4/4) of grade V patients were found to have poor outcomes. Univariate analysis showed that a SAFIRE grade of IV or V was associated with a significantly increased risk of a poor outcome at both the 1-year (OR 2.5, 95% CI 1.5-4.2; p < 0.001) and 6-year (OR 3.7, 95% CI 2.2-6.2; p < 0.001) follow-ups. CONCLUSIONS: High SAFIRE grades are associated with an increased risk of a poor recovery at late follow-up.

Spetzler-Martin Grade III Arteriovenous Malformations: A Multicenter Propensity-Adjusted Analysis of the Effects of Preoperative Embolization.

BACKGROUND: Spetzler-Martin (SM) grade III arteriovenous malformations (AVMs) are at the boundary of safe operability, and preoperative embolization may reduce surgical risks. OBJECTIVE: To evaluate the benefits of preoperative AVM embolization by comparing neurological outcomes in patients with grade III AVMs treated with or without preoperative embolization. METHODS: All microsurgically treated grade III AVMs were identified from 2011 to 2018 at 2 medical centers. Neurological outcomes, measured as final modified Rankin Scale scores (mRS) and changes in mRS from preoperative baseline to last follow-up evaluation, were compared in patients with and without preoperative embolization. RESULTS: Of the 102 patients with grade III AVMs who were treated microsurgically, 57 (56%) underwent preoperative embolization. Significant differences were found between the patients with and without embolization in AVM eloquence (74% vs 93%, P = .02), size ≥ 3 cm (47% vs 73%, P = .01), diffuseness (7% vs 22%, P = .04), and mean final mRS (1.1 vs 2.0, P = .005). Poor outcomes were more frequent in patients without embolization (38%) than with embolization (7%) (final mRS > 2; P < .001). Propensity-adjusted analysis revealed AVM resection without embolization was a risk factor for poor outcome (mRS score > 2; odds ratio, 4.2; 95% CI, 1.1-16; P = .03). CONCLUSION: Nonembolization of SM grade III AVMs is associated with an increased risk of poor neurological outcomes after microsurgical resection. Preoperative embolization of intermediate-grade AVMs selected because of large AVM size, surgical inaccessibility of feeding arteries, and high flow should be employed more often than anticipated, even in the context of increasing microsurgical experience with AVMs.

Difficult-to-Localize Epilepsy After Stereoelectroencephalography: Technique, Safety, and Efficacy of Placing Additional Electrodes During the Same Admission.

BACKGROUND: Stereoelectroencephalography (SEEG) is used to identify the epileptogenic zone (EZ) in patients with epilepsy for potential surgical intervention. Occasionally, the EZ is difficult to localize even after an SEEG implantation. OBJECTIVE: To demonstrate a safe technique for placing additional electrodes in ongoing SEEG evaluations. Describe efficacy, complications, and surgical outcomes. METHODS: An operative technique which involves maintaining previously placed electrodes and sterilely placing new electrodes was developed and implemented. All patients who underwent placement of additional SEEG electrodes during the same admission were retrospectively reviewed. RESULTS: A total of 14 patients met criteria and had undergone SEEG evaluation with 198 electrodes implanted. A total 93% of patients (13/14) had nonlesional epilepsy. After unsuccessful localization of the EZ after a mean of 9.6 d of monitoring, each patient underwent additional placement of electrodes (5.5 average electrodes per patient) to augment the original implantation. At no point did any patients develop new hemorrhage, infection, wound breakdown, or require any kind of additional antimicrobial treatment. A total 64% (9/14) of patients were able to undergo surgery aimed at removing the EZ guided by the additional SEEG electrodes. A total 44% (4/9) of surgical patients had Engel class I outcomes at an average follow-up time of 11 mo. CONCLUSION: Placing additional SEEG electrodes, while maintaining the previously placed electrodes, appears to be safe, effective, and had no infectious complications. When confronted with difficult-to-localize epilepsy even after invasive monitoring, it appears to be safe and potentially clinically effective to place additional electrodes during the same admission.