Treatment modalities and outcomes of granular cell tumors and spindle cell oncocytomas of the pituitary gland: an analysis of two national cancer databases.

BACKGROUND: Spindle cell oncocytomas (SCO) and granular cell tumors (GCT) are rare primary pituitary neoplasms; the optimal treatment paradigms for these lesions are unknown and largely unexplored. Thus, using national registries, we analyze the epidemiology, management patterns, and surgical outcomes of SCOs and GCTs. METHODS: The National Cancer Database (NCDB; years 2003-2017) and the Surveillance, Epidemiology, and End Results Program (SEER; years 2004-2018) were queried for patients with pituitary SCOs or GCTs. Incidence, extent of surgical resection, and rate of postoperative radiation use for subtotally resected lesions comprised the primary outcomes of interest. All-cause mortality was also analyzed via time-to-event Kaplan-Meier curves. RESULTS: SCOs and GCTs have an annual incidence of 0.017 and 0.023 per 1,000,000, respectively. They comprise 0.1% of the benign pituitary tumors registered in NCDB. A total of 112,241 benign pituitary tumors were identified in NCDB during the study period, of which 83 (0.07%) were SCOs and 59 (0.05%) were GCTs. Median age at diagnosis was 55 years, 44% were females, and median maximal tumor diameter at presentation was 2.1 cm. Gross total resection was achieved in 54% patients. Ten patients (7%) had postoperative radiation. Comparing patients with GCTs versus SCOs, the former were more likely to be younger at diagnosis (48.0 vs. 59.0, respectively; p < 0.01) and female (59% vs. 34%, p = 0.01). GCTs and SCOs did not differ in terms of size at diagnoses (median maximal diameter: 1.9 cm vs. 2.2 cm, respectively; p = 0.59) or gross total resection rates (62% vs. 49%, p = 0.32). After matching SCOs and GCTs with pituitary adenomas on age, sex, and tumor size, the former were less likely to undergo gross total resection (53% vs. 72%; p = 0.03). Patients with SCOs and GCTs had a shorter overall survival when compared to patients with pituitary adenomas (p < 0.01) and a higher rate of thirty-day mortality (3.1% vs 0.0%; p = 0.013). CONCLUSION: SCOs and GCTs are rare pituitary tumors, and their management entails particular challenges. Gross total resection is often not possible, and adjuvant radiation might be employed following subtotal resection.

Unplanned returns to the operating room: a quality improvement methodology for the comparison of institutional outcomes to national benchmarks.

OBJECTIVE: Unplanned returns to the operating room (RORs) constitute an important quality metric in surgical practice. In this study, the authors present a methodology to compare a department's unplanned ROR rates with national benchmarks in the context of large-scale quality of care surveillance. METHODS: The authors identified unplanned RORs within 30 days from the initial surgery at their institution during the period 2014-2018 using an institutional documentation platform that facilitates the collection of reoperation information by providers in the clinical setting. They divided the procedures into 28 groups by Current Procedural Terminology and International Classification of Diseases, 9th and 10th Revision codes. They estimated national benchmarks of unplanned RORs for these procedure groups via querying the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) registry during the period 2014-2018. Finally, they numerically assessed the unplanned ROR rates at their institution compared with those calculated from the ACS NSQIP registry. RESULTS: Using the above methodology, the authors were able to classify 12,575 of the cases performed in their department during the period of interest, including 6037 (48%) cranial cases and 6538 (52%) spinal or peripheral nerve cases. Among those, 161 (1.3%) presented with complications that required an unplanned ROR within 30 days from the initial surgery. The respective cumulative unplanned ROR rate in the ACS NSQIP registry during the same timeframe was 3.6%. Among 15 categories of cranial procedures, the cumulative unplanned ROR rate was 1.3% in the authors' department and 5.6% in the ACS NSQIP registry. Among 13 categories of spinal and peripheral nerve procedures, the cumulative unplanned ROR rate was 1.3% in the authors' department and 2.8% in the ACS NSQIP registry. Unplanned ROR rates at the authors' institution were lower than the national average for each of the 28 procedure groups of interest. Yearly analysis of institutional ROR rates for the five most commonly performed procedures showed lower reoperation rates compared with the national benchmarks. CONCLUSIONS: Using an institutional documentation tool and a widely available national database, the authors developed a reproducible and standardized method of comparing their department's outcomes with national benchmarks per procedure subgroup. This methodology accommodates longitudinal quality surveillance across the different subspecialties in a neurosurgical department and may illuminate potential shortcomings of care delivery in the future.

Functional Mapping of Movement and Speech Using Task-Based Electrophysiological Changes in Stereoelectroencephalography.

Introduction: Stereoelectroencephalography (sEEG) has become the predominant method for intracranial seizure localization. When imaging, semiology, and scalp EEG are not in full agreement or definitively localizing, implanted sEEG recordings are used to test candidate seizure onset zones (SOZs). Discovered SOZs may then be targeted for resection, laser ablation, or neurostimulation. If a SOZ is eloquent, resection and ablation are both contraindicated, so identifying functional representation is crucial for therapeutic decision making. Objective: We present a novel functional brain mapping technique that utilizes task-based electrophysiological changes in sEEG during behavioral tasks and test this in pediatric and adult patients. Methods: sEEG was recorded in twenty patients with epilepsy, aged 6-39 (12 female, 18 of 20 patients < 21 years old), who underwent implanted monitoring to identify seizure onset. Each performed 1) visually cued simple repetitive movements of the hand, foot, or tongue while electromyography was recorded, and 2) simple picture naming or verb generation speech tasks while audio was recorded. Broadband changes in the power spectrum of the sEEG were compared between behavior and rest. Results: Electrophysiological functional mapping of movement and/or speech areas was completed in all 20 patients. Eloquent representation was identified in both cortex and white matter, and generally corresponded to classically described functional anatomic organization as well as other clinical mapping results. Robust maps of brain activity were identified in healthy brain, regions of developmental or acquired structural abnormality, and SOZs. Conclusion: Task based electrophysiological mapping using broadband changes in the sEEG signal reliably identifies movement and speech representation in pediatric and adult epilepsy patients.

Embolization of Large and Giant Posterior Fossa Hemangioblastomas: The Experience of a Single Tertiary Care Center.

Background Hemangioblastomas pose an inherent surgical risk due to the potential for high intraoperative blood loss, especially in larger tumors. One approach to minimize this risk is to use preoperative embolization. Herein, we present our institutional experience treating large and giant cerebellar hemangioblastomas. Methods We performed a retrospective chart review of 19 patients with cerebellar hemangioblastomas that had a maximal diameter of >3 cm. We performed a literature review and included individual patient-level data that met our >3 cm diameter cerebellar hemangioblastoma inclusion criteria. Results Our cohort consisted of 19 patients that received a total of 20 resections for their cerebellar hemangioblastomas. Preoperative embolization was utilized in eight cases (38.1%). One patient experienced transient neurological complications after embolization (12.5%). Tumors of patients in the embolization group had larger median total, solid, and cystic volumes and were more likely to involve the cerebellopontine angle than those in the non-embolized group. Compared with non-embolized patients, embolized patients had less decrease in their hemoglobin, lower volumes of estimated blood loss, reduced rates of postoperative complications and permanent deficits, and greater instances of neurological improvement. The larger cohort (obtained from the combining our cohort with patients identified during a literature review) consisted of 99 patients with 39 receiving preoperative embolization. Conclusion It is important to examine individual patient characteristics when determining eligibility for preoperative embolization. However, improvements in endovascular techniques have made preoperative embolization a safe and effective procedure with minimal risks that can be performed in many patients.

Temporo-Parietal Extraventricular Approach for Deep Brain Stimulation Targeting the Anterior Nucleus of the Thalamus: Institutional Experience.

BACKGROUND AND OBJECTIVES: The anterior nucleus of the thalamus (ANT) is a common target for deep brain stimulation (DBS) for drug-resistant epilepsy (DRE). However, the surgical approach to the ANT remains challenging because of its unique anatomy. This study aims to summarize our experience with the posterior temporo-parietal extraventricular (TPEV) approach targeting the ANT for DBS in DRE. METHODS: We performed a retrospective analysis of patients with DRE who underwent ANT-DBS using the TPEV approach between January 2011 and February 2021. Subjects with at least 6-month follow-up were eligible. The final lead position and number of active contacts targeting the anteroventral nucleus (AV) of the ANT were assessed using Lead-DBS. Mean seizure frequency reduction percentage and responder rate (≥50% decrease in seizure frequency) were determined. RESULTS: Thirty-one patients (mean age: 32.9 years; 52% female patients) were included. The mean follow-up period was 27.6 months ± 13.9 (29, 16-36). The mean seizure frequency reduction percentage was 65% ± 26 (75, 50-82). Twenty-six of 31 participants (83%) were responders, P < .001. Two subjects (6%) were seizure-free for at least 6 months at the last evaluation. Antiepileptic drugs dose and/or number decreased in 17/31 subjects (55%). The success rate for placing at least 1 contact at AV was 87% (27/31 patients) bilaterally. The number of active contacts at the AV was significantly greater in the responder group, 3.1 ± 1.3 (3, 2-4) vs 1.8 ± 1.1 (2, 1-2.5); P = .041 with a positive correlation between the number of active contacts and seizure reduction percentage; r = 0.445, R 2 = 0.198, P = .012. CONCLUSION: The TPEV trajectory is a safe and effective approach to target the ANT for DBS. Future studies are needed to compare the clinical outcomes and target accuracy with the standard approaches.

Traumatic posterior cerebral artery dissection and dissecting aneurysms: A systematic review with an illustrative case report.

BACKGROUND: Traumatic posterior cerebral artery (tPCA) dissection and dissecting aneurysms are rare and constitute a challenging clinical entity. OBJECTIVE: We analyze existing literature on tPCA dissection and present our institutional experience. METHODS: We retrospectively queried our database for tPCA isolated dissection or dissecting aneurysms from 2008 until now and conducted a systematic literature review of published cases. We analyzed the clinical and radiographic characteristics and treatment outcomes of tPCA dissection. RESULTS: Including our case, a total of 11 cases with either isolated dissection (n = 2) or dissecting aneurysms (n = 9) were included. The median age was 27 years, and 45% were females. The median interval between trauma and tPCA dissection diagnosis was nine days. Mental status declined in four (36%) patients. Half of the patients demonstrated tentorial subdural hematoma on head CT. Ischemic stroke was detected in three (43%) patients. Four (36%) patients were conservatively managed, one (9.1%) patient was treated with surgical clipping of the proximal PCA, and six patients underwent endovascular treatments. The complication rate was 20%. Immediate total occlusion was demonstrated in five patients (100%), and the conservatively managed case showed immediate, spontaneous thrombosis of the aneurysm. Glasgow Coma Scale scores were 15 in eight (89%) and 14 in one (11%) patients at the last clinical follow-up with a median of six months. The mortality and retreatment rates were null. CONCLUSIONS: tPCA dissection is diagnosed late and commonly affects the young population. The clinical outcome for this condition is typically favorable. Current endovascular techniques showed considerable efficacy and safety.

Complementary and Alternative Medicine for Gliomas: Systematic Review and Critical Appraisal of Current Literature.

BACKGROUND: Many patients with glioma and their caregivers seek complementary and alternative medicine (CAM) methods to comfort themselves, cope with cancer medication side effects, and feel they are taking control of their disease. OBJECTIVE: To summarize existing evidence on safety and efficacy of CAM treatments for gliomas. METHODS: We performed an exhaustive electronic literature search for in vitro, animal, and clinical studies (English language, all years available) on CAM modalities for gliomas. RESULTS: A total of 378 studies (315 unique articles) were analyzed. Distribution was as follows: in vitro-274 (73%), animal-77 (20%), and clinical-26 (7%, 2491 patients). Most studies were conducted in China (n = 135, 43%), followed by the United States (n = 62, 20%) and Spain (n = 17, 5%-6%). Resveratrol was the most commonly investigated CAM therapy in the in vitro (n = 62) and in vivo (n = 17) setting. Safety/toxicity was examined in 21% of in vitro (cytotoxic at same dose in 48%), 39% of in vivo (no evidence of organ toxicity), and 50% of clinical studies (adverse events reported in 6). Cytotoxicity was the most frequent end point among in vitro (60%) and animal studies (56%), followed by synergistic action with chemotherapy and inhibition of invasiveness and migration. Finally, 7 of 26 studies found no clinical effect, whereas 5 reported possible impact on progression-free or overall survival, 3 demonstrated decrease or arrest of tumor progression, and 2 showed positive impact on symptoms and quality of life. CONCLUSION: These findings will hopefully educate providers and patients and stimulate further research in the field of CAM therapy for gliomas.

Predictors of favorable outcome following hypoglossal-to-facial nerve anastomosis for facial nerve palsy: a systematic review and patient-level analysis of a literature-based cohort.

OBJECTIVE: Facial nerve palsy is a debilitating condition that can arise from iatrogenic, traumatic, or congenital causes. One treatment to improve function of the facial muscles after facial nerve injury is hypoglossal-to-facial nerve anastomosis (HFA). HFA's efficacy and predictors of its success vary in the literature. Here, the authors present a patient-level analysis of a literature-based cohort to assess outcomes and investigate predictors of success for HFA. METHODS: Seven electronic databases were queried for studies providing baseline characteristics and outcomes of patients who underwent HFA. Postoperative outcomes were measured using the House-Brackmann (HB) grading scale. A change in HB grade of 3 points or more was classified as favorable. A cutoff value for time to anastomosis associated with a favorable outcome was determined using the Youden Index. RESULTS: Nineteen articles with 157 patients met the inclusion criteria. The mean follow-up length was 27.4 months, and the mean time to anastomosis after initial injury was 16 months. The end-to-side and end-to-end anastomosis techniques were performed on 84 and 48 patients, respectively. Of the 130 patients who had available preoperative and postoperative HB data, 60 (46.2%) had a favorable outcome. Time from initial injury to anastomosis was significantly different between patients with favorable and unfavorable outcomes (7.3 months vs 29.2 months, respectively; p < 0.001). The optimal cutoff for time to anastomosis to achieve a favorable outcome was 6.5 months (area under the curve 0.75). Patients who underwent anastomosis within 6.5 months of injury were more likely to achieve a favorable outcome (73% vs 31%, p < 0.001). CONCLUSIONS: HFA is an effective method for restoring facial nerve function. Favorable outcomes for facial nerve palsy may be more likely to occur when time to anastomosis is within a 6.5-month window.

Systematic review and patient-level meta-analysis of radiofrequency ablation for medically refractory epilepsy: Implications for clinical practice and research.

BACKGROUND: Radiofrequency thermocoagulation (RF-TC) is a minimally invasive procedure for the treatment of epileptic foci. The aim of this study is to review available evidence on the safety and efficacy of RF-TC for medically refractory epilepsy. METHODS: A comprehensive literature search (Pubmed/Medline, EMBASE, Cochrane) was conducted for studies with patient-level data on RF-TC for medically refractory epilepsy. Seizure outcome (Engel classification) at last follow-up comprised the primary endpoint. New temporary or permanent post-procedural neurological deficits were the secondary endpoints. RESULTS: A total of 20 studies (360 patients) were analyzed. Median age at the time of intervention was 29 years (interquartile range (IQR): 21-37) and 57% were males. A lesional MRI was noted in 59% of patients. Median duration of postoperative follow-up was 24 months (IQR: 11-48). The median number of RF-TC lesions per patient was 11 (IQR: 6-19), with bipolar ablation (i.e. between two contiguous contacts) being the most common method (n = 244, 68%). The most common RF-TC location was the mesial temporal structures, without (34%) or with (7%) the temporal neocortex, followed by the insula (13%) and the frontal lobe (12%). Multilobar targets were lesioned in 11% of patients. New neurological deficits developed in 10% of patients (2% remained permanently), with the most common being motor deficits. Among patients with at least 12 months of follow-up (n = 267, 74% of overall cohort), a favorable seizure outcome (Engel I/II class) was achieved in 62% of cases. Patients with a favorable seizure outcome were significantly more likely to have a lesional MRI (71% vs 43% 51%, p < 0.001), have a higher number of RF ablations (15 [IQR 8-31] vs 9 [IQR 4-14], p < 0.001), and undergo monopolar RF-TC (50% vs 30%, p = 0.002). CONCLUSION: Current evidence supports the promising safety and efficacy profile of RF-TC for medically refractory epilepsy. Randomized controlled trial data are needed to further establish the role of this intervention in preoperative discussions with patients and their families.

A mentorship model for neurosurgical training: the Mayo Clinic experience.

Neurosurgical education is a continually developing field with an aim of training competent and compassionate surgeons who can care for the needs of their patients. The Mayo Clinic utilizes a unique mentorship model for neurosurgical training. In this paper, the authors detail the historical roots as well as the logistical and experiential characteristics of this teaching model. This model was first established in the late 1890s by the Mayo brothers and then adopted by the Mayo Clinic Department of Neurological Surgery at its inception in 1919. It has since been implemented enterprise-wide at the Minnesota, Florida, and Arizona residency programs. The mentorship model is focused on honing resident skills through individualized attention and guidance from an attending physician. Each resident is closely mentored by a consultant during a 2- or 3-month rotation, which allows for exposure to more complex cases early in their training. In this model, residents take ownership of their patients' care, following them longitudinally during their hospital course with guided oversight from their mentors. During the chief year, residents have their own clinic, operating room (OR) schedule, and OR team and service nurse. In this model, chief residents conduct themselves more in the manner of an attending physician than a trainee but continue to have oversight from staff to provide a "safety net." The longitudinal care of patients provided by the residents under the mentorship model is not only beneficial for the trainee and the hospital, but also has a positive impact on patient satisfaction and safety. The Mayo Clinic Mentorship Model is one of many educational models that has demonstrated itself to be an excellent approach for resident education.

The endonasal midline inferior intercavernous approach to the cavernous sinus: technical note, cadaveric step-by-step illustration, and case presentation.

PURPOSE: Traditional endoscopic endonasal approaches to the cavernous sinus (CS) open the anterior CS wall just medial to the internal carotid artery (ICA), posing risk of vascular injury. This work describes a potentially safer midline sellar entry point for accessing the CS utilizing its connection with the inferior intercavernous sinus (IICS) when anatomically present. METHODS: The technique for the midline intercavernous dural access is described and depicted with cadaveric dissections and a clinical case. RESULTS: An endoscopic endonasal approach exposed the periosteal dural layer of anterior sella and CS. The IICS was opened sharply in midline through its periosteal layer. The feather knife was inserted and advanced laterally within the IICS toward the anterior CS wall, thereby gradually incising the periosteal layer of the IICS. The knife was turned superiorly then inferiorly in a vertical direction to open the anterior CS wall. This provided excellent access to the CS compartments, maintained the meningeal layer of the IICS and the medial CS wall, and avoided an initial dural incision immediately adjacent to the ICA. CONCLUSION: The midline intercavernous dural access to the CS assisted by a 90° dissector-blade is an effective modification to previously described techniques, with potentially lower risk to the ICA.

Inferior Clinical Outcomes for Patients with Medicaid Insurance After Surgery for Degenerative Lumbar Spondylolisthesis: A Prospective Registry Analysis of 608 Patients.

BACKGROUND: It remains unclear how type of insurance coverage affects long-term, spine-specific patient-reported outcomes (PROs). This study sought to elucidate the impact of insurance on clinical outcomes after lumbar spondylolisthesis surgery. METHODS: The prospective Quality Outcomes Database registry was queried for patients with grade 1 degenerative lumbar spondylolisthesis who underwent single-segment surgery. Twenty-four-month PROs were compared and included Oswestry Disability Index, Numeric Rating Scale (NRS) back pain, NRS leg pain, EuroQol-5D, and North American Spine Society Satisfaction. RESULTS: A total of 608 patients undergoing surgery for grade 1 degenerative lumbar spondylolisthesis (mean age, 62.5 ± 11.5 years and 59.2% women) were selected. Insurance types included private insurance (n = 319; 52.5%), Medicare (n = 235; 38.7%), Medicaid (n = 36; 5.9%), and Veterans Affairs (VA)/government (n = 17; 2.8%). One patient (0.2%) was uninsured and was removed from the analyses. Regardless of insurance status, compared to baseline, all 4 cohorts improved significantly regarding ODI, NRS-BP, NRS-LP, and EQ-5D scores (P < 0.001). In adjusted multivariable analyses, compared with patients with private insurance, Medicaid was associated with worse 24-month postoperative Oswestry Disability Index (ß = 10.2; 95% confidence interval [CI], 3.9-16.5; P = 0.002) and NRS leg pain (ß =1.3; 95% CI, 0.3-2.4; P = 0.02). Medicaid was associated with worse EuroQol-5D scores compared with private insurance (ß = -0.07; 95% CI -0.01 to -0.14; P = 0.03), but not compared with Medicare and VA/government insurance (P > 0.05). Medicaid was associated with lower odds of reaching ODI minimal clinically important difference (odds ratio, 0.2; 95% CI, 0.03-0.7; P = 0.02) compared with VA/government insurance. NRS back pain and North American Spine Society satisfaction did not differ by insurance coverage (P > 0.05). CONCLUSIONS: Despite adjusting for potential confounding variables, Medicaid coverage was independently associated with worse 24-month PROs after lumbar spondylolisthesis surgery compared with other payer types. Although all improved postoperatively, those with Medicaid coverage had relatively inferior improvements.

Survival and associated predictors for patients with pineoblastoma or pineal parenchymal tumors of intermediate differentiation older than 3 years: Insights from the National Cancer Database.

Background: The management of pineal parenchymal tumors remains controversial. Methods: The 2004-2017 National Cancer Database was queried for cases (age >3 years) with histologically confirmed pineal parenchymal tumors of intermediate differentiation (PPTID, n = 90) or pineoblastoma (n = 106). Results: Within the PPTID group, median age was 41 years; 49% were males. Five- and 10-year survival were 83% and 78%, respectively. Adjuvant radiation and chemotherapy were administered in 64% and 17% patients, respectively. The effect of radiation with or without chemotherapy (HR 1.15, P = .81, and HR 1.31, P = .72, respectively), and extent of resection (HR = 1.07, P = .93) was not significant. Within the pineoblastoma group, median age was 25 years; 51% were males. Five- and 10-year survival were 66% and 42%, respectively. Adjuvant radiation and chemotherapy were administered in 72% and 51%, respectively. In multivariable analysis, patients with pineoblastoma who received both radiation and chemotherapy (n = 39) had significantly lower hazard of death (HR 0.35, 95% CI 0.14-0.85, P = .02) compared to those who received radiation alone (n = 20) or no adjuvant treatment (n = 19). Finally, females in the pineoblastoma group were found to have a lower hazard of death compared to males (HR 0.24, 95% CI 0.10-0.58, P = .001); this comparison trended toward statistical significance in the PPTID subgroup (HR 0.40, 95% CI 0.14-1.08, P = .07). Conclusions: Survival rates were higher in patients with PPTID vs patients with pineoblastoma. Adjuvant chemoradiation was associated with improved survival in pineoblastoma and females had lower hazards of death. Further research should identify specific patient profiles and molecular subgroups more likely to benefit from multimodality therapy.

Low occurrence of long-term subsequent fusion in pediatric patients following decompressive surgery for Chiari malformation: an institutional review.

OBJECTIVE: Chiari I malformation is treated with suboccipital craniectomy with cervical laminectomy, a procedure which has been associated with the possibility of pre-existing or iatrogenic occipitocervical instability. The long-term risk of subsequent spinal deformity and need for occipito cervical fusion after standard Chiari decompression in pediatric patients has not yet been characterized. METHODS: We queried our institutional electronic database for patients aged 18 and under, with at least 5 years of follow-up, that underwent surgical decompression for Chiari I malformation. Occurrence of subsequent occipitocervical fusion at follow-up comprised the primary endpoint. Cases with myelomeningocele, Chiari II, or fusion at time of decompression were excluded. RESULTS: A total of 30 patients (median age 5.5 years, 60% males) were analyzed. Age distribution was as follows: n = 3 for 0-1 years, n = 11 for 1-5 years, n = 4 for 5-10 years, and n = 12 for 10-18 years. Median tonsillar descent below the foramen magnum was 12.5 mm (interquartile range [IQR]: 10.8-19.5 mm). Syringomyelia was observed in 43%, retroflexion of the dens in 55%, basilar invagination in 6.7%, and medullary kinking in 27%. The median clivo-axial angle was 142° (132-150°). The majority of patients underwent C1 laminectomy (n = 24, 80%), followed by C1-C2 laminectomy (n = 4, 13%), while one patient had C1-upper C2 and C1-C3 laminectomy each, respectively. At a median follow-up of 6.3 years, there was only one patient (3.3% of overall cohort) that underwent subsequent occipitocervical fusion. The patient (4-year-old male) initially had a suboccipital craniectomy with C1 laminectomy and duraplasty and presented with recurrence of posterior headaches and neck pain 4 months after original surgery. We proceeded with occiput-C2 fusion with subsequent resolution of his symptoms. CONCLUSION: Current analysis shows that in the absence of clinical or imaging features suggestive of craniocervical instability, Chiari I decompressive surgery is associated with very low long-term risk of requiring occipitocervical fusion. This observance can be used to guide surgical treatment decisions, especially in young children with Chiari I malformations.