Factors Associated with Extended Hospitalization in Patients Who Had Adjuvant Middle Meningeal Artery Embolization After Conventional Surgery for Chronic Subdural Hematomas.

BACKGROUND: This study aims to evaluate the length of stay (LOS) in patients who had adjunct middle meningeal artery embolization (MMAE) for chronic subdural hematoma after conventional surgery and determine the factors influencing the LOS in this population. METHODS: A retrospective review of 107 cases with MMAE after conventional surgery between September 2018 and January 2024 was performed. Factors associated with prolonged LOS were identified through univariable and multivariable analyses. RESULTS: The median LOS for MMAE after conventional surgery was 9 days (interquartile range = 6-17), with a 3-day interval between procedures (interquartile range = 2-5). Among 107 patients, 58 stayed ≤ 9 days, while 49 stayed longer. Univariable analysis showed the interval between procedures, type of surgery, MMAE sedation, and the number of complications associated with prolonged LOS. Multivariable analysis confirmed longer intervals between procedures (odds ratio [OR] = 1.52; P < 0.01), ≥2 medical complications (OR = 13.34; P = 0.01), and neurological complications (OR = 5.28; P = 0.05) were independent factors for lengthier hospitalizations. There was a trending association between general anesthesia during MMAE and prolonged LOS (P = 0.07). Subgroup analysis revealed diabetes (OR = 5.25; P = 0.01) and ≥2 medical complications (OR = 5.21; P = 0.03) correlated with a LOS over 20 days, the 75th percentile in our cohort. CONCLUSIONS: The interval between procedures and the number of medical and neurological complications were strongly associated with prolonged LOS in patients who had adjunct MMAE after open surgery. Reducing the interval between the procedures and potentially performing both under 1 anesthetic may decrease the burden on patients and shorten their hospitalizations.

Surgery in octogenarians with intracranial meningiomas improves functional outcome at 1 year.

PURPOSE: The population is aging, and age remains an important factor in deciding surgical candidacy for intracranial tumors. The natural history and surgical behavior of meningiomas in octogenarians are not well understood. We evaluated the surgical and functional outcomes, including survival, among octogenarians with intracranial meningiomas in a single institution. METHODS: The Tumor Registry (2004-2021) was used to identify octogenarian patients (ages 80-89) diagnosed with intracranial meningioma. Primary endpoints were 1-year survival and functional outcome measured with mRS postsurgery. Kaplan-Meier, univariable Log-rank tests, and multivariable Cox hazards proportional regression models were used for assessing factors associated with overall survival (OS) in octogenarians with meningiomas who underwent surgery; logistic regression and McNemar's were used to further characterize risk factors affecting functional surgical outcome at 1 year. RESULTS: Thirty octogenarians with intracranial meningioma who underwent surgery were identified. Median age was 82.5 years and 66.6% were female patients. The 1-year median postsurgical survival probability for all octogenarians with meningioma was 86.3% and no intraoperative mortality was observed. Frailty (mFI-5, p = 0.84), tumor grade (p = 0.11), tumor size (p = 0.22), extent of resection (p = 0.35), and Karnofsky scale on admission (p = 0.93) did not significantly affect the survival in octogenarians with meningiomas which were treated surgically. The 1-year postoperative functional status of octogenarian meningioma patients who underwent surgery was significantly improved compared to pre-op mRS (McNemar's chi-squared = 9.6, df = 1, p-value = 0.001946). CONCLUSION: In octogenarians with meningiomas, surgical intervention significantly improves the pre-operative modified Rankin Scale at 1 year postsurgery in this cohort.

Intracranial Metastasis of Extracranial Chondrosarcoma: Systematic Review With Illustrative Case.

BACKGROUND: Cerebral chondrosarcoma metastases are rare and aggressive neoplasms. The rarity of presentation has precluded rigorous analysis of diagnosis, risk factors, treatment, and survival. We analyzed every reported case through exhaustive literature review. We further present the first case with Maffucci syndrome. METHODS: Three databases, PubMed, Embase, and Google Scholar, and crossed references were queried for cerebral chondrosarcoma metastases. Extracted variables included demographics, risk factors, tumor characteristics, interventions, and outcomes. Univariate and multivariate analyses were performed. RESULTS: Fifty-six patients were included from 1,489 literature results. The average age at brain metastasis was 46.6±17.6 years and occurred at a median of 24±2.8 months from primary diagnosis. Primary tumor histology (dedifferentiated 5.0±1.5 months, mesenchymal 24±3.0 months, conventional 41±7.4 months, p<0.05) and grade (low grade 54±16.7 months vs. high-grade 10±6.4 months, p<0.001) correlated with time interval until brain metastasis. A multiple enchondromatosis syndrome occurred in 13.2% of cases. At time of brain metastases diagnosis, extracranial metastases were identified in 76.2% of cases. Median survival after the development of brain metastasis was 2.0±0.78 months with a 1-year survival of 10.0%. On regression analysis, surgery reduced brain metastasis mortality risk and radiation trended towards reduced mortality risk (surgery: hazard ratio [HR] 0.22, 95% confidence interval [CI] 0.064-0.763, p=0.017; radiation: HR 0.31, 95% CI 0.091-1.072, p=0.064). CONCLUSION: We present a systematic review of cerebral chondrosarcoma metastases. Primary tumor histology and grade correlate with time until cerebral metastasis. Following cerebral metastasis, these tumors have poor prognosis and modestly benefit from surgery.

Prevalence and Predictors of Inappropriate Antithrombotic Prescription in Patients Presenting With Traumatic Brain Injury.

BACKGROUND AND OBJECTIVES: A growing proportion of the US population is on antithrombotic therapy (AT), most significantly within the older subpopulation. Decision to use AT is a balance between the intended benefits and known bleeding risk, especially after traumatic brain injury (TBI). Preinjury inappropriate AT offers no benefit for the patient and also increases the risk of intracranial hemorrhage and worse outcome in the setting of TBI. Our objective was to examine the prevalence and predictors of inappropriate AT among patients presenting with TBI to a Level-1 Trauma Center. METHODS: A retrospective chart review was performed on all patients with TBI and preinjury AT who presented to our institution between January 2016 and September 2020. Demographic and clinical data were collected. Appropriateness of AT was determined through established clinical guidelines. Clinical predictors were determined by logistic regression. RESULTS: Of 141 included patients, 41.8% were female (n = 59) and the average age (mean ± SD) was 80.6 ± 9.9. The prescribed antithrombotic agents included aspirin (25.5%, n = 36), clopidogrel (22.7%, n = 32), warfarin (46.8%, n = 66), dabigatran (2.1%, n = 3), rivaroxaban (Janssen) (10.6%, n = 15), and apixaban (Bristol-Myers Squibb Co.) (18.4%, n = 26). The indications for AT were atrial fibrillation (66.7%, n = 94), venous thromboembolism (13.4%, n = 19), cardiac stent (8.5%, n = 12), and myocardial infarction/residual coronary disease (11.3%, n = 16). Inappropriate antithrombotic therapy use varied significantly by antithrombotic indication ( P < .001) with the highest rates seen with venous thromboembolism. Predictive factors also include age ( P = .005) with higher rates younger than 65 years and older than 85 years and female sex ( P = .049). Race and antithrombotic agent were not significant predictors. CONCLUSION: Overall, 1 in 10 patients presenting with TBI were found to be on inappropriate AT. Our study is the first to describe this problem and warrants investigation into possible workflow interventions to prevent post-TBI continuation of inappropriate AT.

Predictors of extended length of stay related to craniotomy for tumor resection.

Background: Hospital length of stay (LOS) related to craniotomy for tumor resection (CTR) is a marker of neurosurgical quality of care. Limiting LOS benefits both patients and hospitals. This study examined which factors contribute to extended LOS (eLOS) at our academic center. Methods: Retrospective medical record review of 139 consecutive CTRs performed between July 2020 and July 2021. Univariate and multivariable analyses determined which factors were associated with an eLOS (≥8 days). Results: Median LOS was 6 days (IQR 3-9 days). Fifty-one subjects (36.7%) experienced an eLOS. Upon univariate analysis, potentially modifiable factors associated with eLOS included days to occupational therapy (OT), physical therapy (PT), and case management clearance (p < .001); and discharge disposition (p < .001). Multivariable analysis revealed that pre-operative anti-coagulant use (OR 10.74, 95% CI 2.64-43.63, p = .001), Medicare (OR 4.80, 95% CI 1.07-21.52, p = .04), ED admission (OR 26.21, 95% CI 5.17-132.99, p < .001), transfer to another service post-surgery (OR 30.00, 95% CI 1.56-577.35, p = .02), and time to post-operative imaging (OR 2.91, 95% CI 1.27-6.65, p = .01) were associated with eLOS. Extended LOS was not significantly associated with ED visits (p = .45) or unplanned readmissions within 30 days of surgery (p = .35), and both (p = .04; p = .04) were less likely following a short LOS (<5 days). Conclusion: While some factors driving LOS related to CTR are uncontrollable, expedient pre- and post-operative management may reduce LOS without compromising care.

Targeting Accuracy of the Leksell Vantage Stereotactic System for Deep Brain Stimulation Surgery: A Retrospective Review.

BACKGROUND: Compared with the Leksell G frame, the new Leksell Vantage stereotactic headframe offers many benefits during deep brain stimulation (DBS) procedures. OBJECTIVE: To define the "real-world" targeting accuracy of the Vantage frame for performing DBS lead implants. METHODS: Retrospective review of all patients who underwent DBS using the Vantage frame with our surgeon between July 2021 and May 2022. Target and actual coordinates of implanted DBS leads were determined in BrainLab. RESULTS: Thirty-three electrode trajectories (17 left-sided, 16 right-sided) were included. On the right, actual electrode placement was, on average, 0.95 mm more medial, 1.06 mm more posterior, and 0.55 mm more superior compared with planned trajectories. The vector error was 1.93 ± 0.91 mm. On the left, actual electrode placement was 0.49 mm more lateral, 0.66 mm more posterior, and 0.67 mm more superior than planned trajectories. The vector error was 1.68 ± 0.66 mm. After excluding all electrodes that were repositioned after microelectrode recording and/or test stimulation, right-sided electrodes (n = 10) were 0.88 mm more medial, 0.94 mm more posterior, and 0.76 mm more superior than planned trajectories. The vector error was 1.74 ± 1.01 mm. Left-sided electrodes (n = 14) were 0.49 mm more lateral, 0.63 mm more posterior, and 0.49 mm more superior than planned trajectories. The vector error was 1.62 ± 0.68 mm. CONCLUSION: This study demonstrated the accuracy of the Leksell Vantage frame in comparison with the traditional Leksell G frame.

Outcome of Chronic Subdural Hematoma Intervention in Patients on Long-Term Antiplatelet Therapy-A Propensity Score Matched Analysis.

BACKGROUND: Patients presenting with chronic subdural hematomas (cSDHs) and on antiplatelet medications for various medical conditions often complicate surgical decision making. OBJECTIVE: To evaluate risks of preprocedural and postprocedural antiplatelet use in patients with cSDHs. METHODS: Patients with cSDH who were treated between January 2006 and February 2022 at a single institution with surgical intervention were identified. A propensity score matching analysis was then performed analyzing length of hospitalization, periprocedural complications, reintervention rate, rebleeding risk, and reintervention rates. RESULTS: Preintervention, 178 patients were on long-term antiplatelet medication and 298 were not on any form of antiplatelet. Sixty matched pairs were included in the propensity score analysis. Postintervention, 88 patients were resumed on antiplatelet medication, whereas 388 patients did not have resumption of antiplatelets. Fifty-five pairs of matched patients were included in the postintervention propensity score analysis. No significant differences were found in length of hospitalization (7.8 ± 4.2 vs 6.8 ± 5.4, P = .25), procedural complications (3.3% vs 6.7%, P = .68), or reintervention during the same admission (3.3% vs 5%, P = 1). No significant differences were seen in recurrence rate (9.1% vs 10.9%, P = 1) or reintervention rate after discharge (7.3% vs 9.1%, P = 1) in the postintervention group. CONCLUSION: Preintervention antiplatelet medications before cSDH treatment do not affect length of hospitalization, periprocedural complications, or reintervention. Resumption of antiplatelet medication after cSDH procedures does not increase the rebleeding risk or reintervention rate.

Effect of long-term anticoagulant therapy on the outcome of chronic subdural hematoma: a propensity score-matched analysis.

OBJECTIVE: Chronic subdural hematomas (cSDHs) are particularly common in older adults who have increased risk of falls and the conditions that require anticoagulants (ACs). In such cases, clinicians are often left with the dilemma of co-managing the cSDH and the ongoing need for ACs. METHODS: Patients who underwent surgical management for cSDH at the authors' institution between January 2006 and June 2022 were identified. Propensity score-matched analysis was used to obtain a balance in patients who were on ACs before the procedure versus those who were not, and in patients who were on ACs postprocedure versus those who were not. Length of hospitalization, periprocedural complications, reintervention rate during the same admission, rebleeding risk, and reintervention rates after discharge were compared. RESULTS: In total, 104 patients were on long-term ACs before the procedure, whereas 372 were not. After matching, 55 pairs were included in the analysis. Postprocedure, 74 patients were started on long-term ACs; the rest were not. A total of 49 patients in each group were then included in the analysis after matching. Comparing the preprocedure AC group with the non-AC group, no significant differences were found in length of hospitalization (8.5 ± 6.7 days vs 8.1 ± 7.7 days, p = 0.75), periprocedural complications (7.3% vs 7.3%, p > 0.99), or reintervention during the same admission (1.8% vs 5.5%, p = 0.31). In the comparison of postprocedure AC and non-AC groups, no significant differences were seen in recurrence rate (8.2% vs 14.3%, p = 0.52), reintervention rate after discharge (4.1% vs 14.3%, p = 0.16), or disability (i.e., mRS ≤ 2; 83.7% vs 89.8%, p = 0.55). CONCLUSIONS: Being treated with long-term ACs before cSDH procedures does not affect length of hospitalization, periprocedural complications, or reintervention during the same admission. Similarly, administration of long-term ACs after a procedure for cSDH does not increase rebleeding risk or reintervention rate. Patients who are on long-term ACs can have similar interventions to those who are not on ACs. In addition, it is safe to restart patients on AC agents in a 7- to 14-day window after admission for cSDH with or without acute/subacute components.

Reduced recurrence of chronic subdural hematomas treated with open surgery followed by middle meningeal artery embolization compared to open surgery alone: a propensity score-matched analysis.

OBJECTIVE: Middle meningeal artery embolization (MMAE) is an emerging endovascular treatment technique with proven promising results for chronic subdural hematomas (cSDHs). MMAE as an adjunct to open surgery is being utilized with the goal of preventing the recurrence of cSDH. However, the efficacy of MMAE following surgical evacuation of cSDH has not been clearly demonstrated. The authors sought to compare the outcomes of open surgery followed by MMAE versus open surgery alone. METHODS: Patients who underwent surgical evacuation alone (open surgery-alone group) or MMAE along with open surgery for cSDH (adjunctive MMAE group) were identified at the authors' institution. Two balanced groups were obtained through propensity score matching. Primary outcomes included recurrence risk and reintervention rate. Secondary outcomes included decrease in hematoma size and modified Rankin Scale (mRS) score at last follow-up. Variables in the two groups were compared by use of the Mann-Whitney U-test, paired-sample t-test, and Fisher's exact test. RESULTS: A total of 345 cases of open surgery alone and 52 cases of open surgery with adjunctive MMAE were identified. After control for subjective confounders, 146 patients treated with open surgery alone and 41 with adjunctive MMAE following open surgery with drain placement were included in the analysis. Before matching, the rebleeding risk and reintervention rate for open surgery trended higher in the open surgery alone than the open surgery plus MMAE group (14.4% vs 7.3%, p = 0.18; and 11.6% vs 4.9%, p = 0.17, respectively). No significant differences were seen in duration of radiographic or clinical follow-ups or decreases in hematoma size and mRS score at last follow-up. After one-to-one nearest neighbor propensity score matching, 26 pairs of cases were compared for outcomes. Rates of recurrence (7.7% vs 30.8%, p = 0.038) and overall reintervention (3.8% vs 23.1%, p = 0.049) after open surgery were found to be significantly lower in the adjunctive MMAE group than the open surgery-alone group. With one-to-many propensity score matching, 76 versus 37 cases were compared for open surgery alone versus adjunctive MMAE following open surgery. Similarly, the adjunctive MMAE group had significantly lower rates of recurrence (5.4% vs 19.7%, p = 0.037) and overall reintervention (2.7% vs 14.5%, p = 0.049). CONCLUSIONS: Adjunctive MMAE following open surgery can lower the recurrence risks and reintervention rates for cSDH.

Complications Related to Deep Brain Stimulation Lead Implantation: A Single-Surgeon Case Series.

BACKGROUND: Deep brain stimulation (DBS) is the mainstay of surgical treatment for movement disorders, yet previous studies have shown widely varying complication rates. Given the elective nature of DBS surgery, minimizing surgical complications is imperative. OBJECTIVE: To evaluate short-term and long-term complications related to DBS lead implantation surgeries performed by an experienced surgeon and provide an updated benchmark comparison for other DBS centers and alternative therapies. METHODS: A retrospective chart review of patients who underwent DBS lead implantation surgery by a single surgeon at our institution between 2012 and 2020 was conducted. Demographic and clinical data including surgical complications were collected. A Kaplan-Meier survival analysis was used to evaluate the cumulative risk of lead revision or removal over time. Associations between patient characteristics and various complications were evaluated. RESULTS: Four hundred fifty-one DBS leads were placed in 255 patients. Thirteen leads and 11 patients required revision. In total, 3.6% (95% CI [1.3%-5.9%]) of patients required revision at 1 year and 4.8% (95% CI [1.9%-7.6%]) at 5 years, with per-lead revision rates of 2.3% (95% CI [0.9%-3.6%]) and 3.3% (95% CI [1.5%-5.1%]), respectively. Less common diagnoses such as Tourette syndrome, post-traumatic tremor, and cluster headache trended toward association with lead revision or removal. CONCLUSION: DBS performed by an experienced surgeon is associated with extremely low complication rates.

Moral Distress and Moral Injury Among Attending Neurosurgeons: A National Survey.

BACKGROUND: "Moral distress" describes the psychological strain a provider faces when unable to uphold professional values because of external constraints. Recurrent or intense moral distress risks moral injury, burnout, and physician attrition but has not been systematically studied among neurosurgeons. OBJECTIVE: To develop a unique instrument to test moral distress among neurosurgeons, evaluate the frequency and intensity of scenarios that may elicit moral distress and injury, and determine their impact on neurosurgical burnout and turnover. METHODS: An online survey investigating moral distress, burnout, and practice patterns was emailed to attending neurosurgeon members of the Congress of Neurological Surgeons. Moral distress was evaluated through a novel survey designed for neurosurgical practice. RESULTS: A total of 173 neurosurgeons completed the survey. Half of neurosurgeons (47.7%) reported significant moral distress within the past year. The most common cause was managing critical patients lacking a clear treatment plan; the most intense distress was pressure from patient families to perform futile surgery. Multivariable analysis identified burnout and performing ≥2 futile surgeries per year as predictors of distress (P < .001). Moral distress led 9.8% of neurosurgeons to leave a position and 26.6% to contemplate leaving. The novel moral distress survey demonstrated excellent internal consistency (Cronbach alpha = 0.89). CONCLUSION: We developed a reliable survey assessing neurosurgical moral distress. Nearly, half of neurosurgeons suffered moral distress within the past year, most intensely from external pressure to perform futile surgery. Moral distress correlated with burnout risk caused 10% of neurosurgeons to leave a position and a quarter to consider leaving.

Middle Meningeal Artery Embolization Versus Conventional Treatment of Chronic Subdural Hematomas.

BACKGROUND: Middle meningeal artery (MMA) embolization is an emerging minimally invasive endovascular technique for chronic subdural hematoma (cSDH). Currently, limited literature exists on its safety and efficacy compared with conventional treatment (open-surgical-evacuation-only). OBJECTIVE: To compare MMA embolization to conventional treatment. METHODS: Retrospective analysis of patients with cSDHs treated with MMA embolization in a single center from 2018 to 2019 was performed. Comparisons were made with a historical conventional treatment cohort from 2006 to 2016. Propensity score matching analysis was used to assemble a balanced group of subjects. RESULTS: A total of 357 conventionally treated cSDH and 45 with MMA embolization were included. After balancing with propensity score matching, a total of 25 pairs of cSDH were analyzed. Comparing the embolization with the conventional treatment group yielded no significant differences in complications (4% vs 4%; P > .99), clinical improvement (82.6% vs 83.3%; P = .95), cSDH recurrence (4.3% vs 21.7%; P = .08), overall re-intervention rates (12% vs 24%; P = .26), modified Rankin scale >2 on last follow-up (17.4% vs 32%; P = .24), as well as mortality (0% vs 12%; P = .09). Radiographic improvement at last follow-up was significantly higher in the open surgery cohort (73.9% vs 95.6%; P = .04). However, there was a trend for lengthier last follow-up for the historical cohort (72 vs 104 d; P = .07). CONCLUSION: There was a trend for lower recurrence and mortality rates in the embolization era cohort. There were significantly higher radiological improvement rates on last follow-up in the surgical only cohort era. There were no significant differences in complications and clinical improvement.

A tale of two tinnituses: Does hearing status influence central tinnitus localization?

Tinnitus is a complex symptom that manifests as the perception of sound in the absence of external stimuli. There are various patient-related factors and co-morbidities associated with tinnitus, however, the impact of hearing status on tinnitus is poorly understood. Various works suggest that tinnitus may originate in the central nervous system (CNS). Reports of tinnitus resolution following central insult provide further support for this concept. Based on these reports of tinnitus resolution, a line of research evaluating deep brain stimulation (DBS) of the caudate as a therapy for tinnitus has emerged. The emerging data show early promise and independent evaluation of this work suggests that hearing status may influence localization of tinnitus within the caudate. We closely review the available reports of tinnitus resolution following central insult and tinnitus outcomes in DBS to hypothesize that the CNS origins of tinnitus may vary based on hearing status. Our interpretation of the available literature suggests that the anterior aspect of the caudate may be a location for tinnitus intervention in patients with normal hearing or mild hearing loss (HL) and more posterior locations in the caudate may be a region of intervention in patients with moderate/ severe HL. Ultimately, this concept may shift the paradigm of thought on tinnitus to offer clinically and anatomically relevant information with targeted therapeutic options.

GCB-type is a favorable prognostic factor in primary CNS diffuse large B-cell lymphomas.

Primary CNS lymphomas (PCNSLs) are aggressive diffuse large B-cell lymphomas (DLBCLs) limited to the CNS that generally have a poor prognosis. Classification of DLBCL into germinal center B-cell (GCB) and activated B-cell (non-GCB) subtypes has prognostic value in systemic DLBCL, with GCB-type having a better prognosis. The aim of this study was to determine whether GCB versus non-GCB classification in PCNSLs has similar prognostic value. We analyzed clinical, radiological and histologic data from 24 patients with biopsy confirmed DLBCL of the CNS with classification into GCB versus non-GCB subtypes. We found that after a median follow-up of 15 months, only 39% of patients with non-GCB-type PCNS DLBCL were alive, whereas all patients with GCB-type were alive. Non-GCB-type had a median survival of 11 months, whereas all GCB-type patients were alive after a median follow-up of 22 months. As previously reported, we also found that patients younger than 70 years had longer survival (median 29 months) compared to older patients (median 8.8 months). There was no statistically significant difference between the ages, gender, focality, size or location of lesions, or treatment of non-GCB and GCB-type patients. Our findings suggest that classifying PCNSLs into GCB versus non-GCB subtype using the Hans algorithm may help stratify patients into two groups with different prognosis.

Risk Factors for Wire Fracture or Tethering in Deep Brain Stimulation: A 15-Year Experience.

BACKGROUND: In deep brain stimulation (DBS), tunneled lead and extension wires connect the implantable pulse generator to the subcortical electrode, but circuit discontinuity and wire revision compromise a significant portion of treatments. OBJECTIVE: To identify factors predisposing to fracture or tethering of the lead or extension wire in patients undergoing DBS. METHOD: Retrospective review of wire-related complications was performed in a consecutive series of patients treated with DBS at a tertiary academic medical center over 15 yr. RESULTS: A total of 275 patients had 513 extension wires implanted or revised. There were 258 extensions of 40 cm implanted with a postauricular connector (50.3%), 229 extensions of 60 cm with a parietal connector (44.6%), and 26 extensions 40 cm with a parietal connector (5.1%). In total, 26 lead or extension wires (5.1%) were replaced for fracture. Fracture rates for 60 cm extensions with a parietal connector, 40 cm wires with a postauricular connector, and 40 cm extensions with a parietal connector were 0.2, 1.4, and 12.9 fractures per 100 wire-years, significantly different on log-rank test. Total 16 (89%) 40 cm extension wires with a postauricular connector had fracture implicating the lead wire. Tethering occurred only in patients with 60 cm extensions with parietal connectors (1.14 tetherings per 100 wire-years). Reoperation rate correlated with younger age, dystonia, and target in the GPI. CONCLUSION: The 40 cm extensions with parietal connectors have the highest fracture risk and should be avoided. Postauricular connectors risk lead wire fracture and should be employed cautiously. The 60 cm parietal wires may reduce fracture risk but increase tethering risk.

Factors Affecting the Diagnostic Yield of Frame-Based Stereotactic Intracranial Biopsies.

OBJECTIVE: Frame-based stereotactic biopsy (FSB) remains the "gold standard" for obtaining diagnostic samples of intracranial lesions to guide therapy. Nevertheless, diagnostic yield is highly variable. This study aims to provide an analysis of diagnostic yield, surgical complications, and factors associated with obtaining nondiagnostic samples in a contemporary FSB series. METHODS: A retrospective cohort study was conducted of all adult patients with imaging-documented lesions undergoing FSB at our institution between 2013 and 2018. Diagnostic accuracy, lesion characteristics associated with nondiagnostic biopsy, and surgical complications were evaluated. A biopsy was considered nondiagnostic if all frozen samples and the final pathology yielded normal brain tissue or nonspecific reactive tissue unless the "reactive" pathology was consistent with radiation injury from prior therapy. RESULTS: Our search identified 198 FSB patients. Mean (standard deviation) age was 62 ± 17 years, and 44.2% were female. Median procedure time was 32 minutes. A definitive histologic diagnosis was established in 187 cases (94.4% diagnostic yield). Mean lesion diameter was 31.9 ± 16.8 mm. Multivariable logistic regression revealed only lesion diameter to be significantly associated with diagnostic result (odds ratio for nondiagnostic result: 0.94 per mm diameter decrease, 95% confidence interval 0.87-0.99, P = 0.028). On univariable analysis, diagnosis of central nervous system lymphoma appeared to increase the risk of a nondiagnostic biopsy (P = 0.025), but this association disappeared when controlling for lesion size and steroid administration before biopsy. Eight patients (4.0%) developed postoperative hemorrhagic complications, 3 of whom required reoperation, and another expired. CONCLUSIONS: This study demonstrates that diagnostic yield from contemporary FSB is high and depends predominantly on lesion size.