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Objective: Congenital anomalies of the atlanto-occipital articulation may be present in patients with Chiari malformation type I (CM-I). However, it is unclear how these anomalies affect the biomechanical stability of the craniovertebral junction (CVJ) and whether they are associated with an increased incidence of occipitocervical fusion (OCF) following posterior fossa decompression (PFD). The objective of this study was to determine the prevalence of condylar hypoplasia and atlas anomalies in children with CM-I and syringomyelia. The authors also investigated the predictive contribution of these anomalies to the occurrence of OCF following PFD (PFD+OCF)., Methods: The authors analyzed the prevalence of condylar hypoplasia and atlas arch anomalies for patients in the Park-Reeves Syringomyelia Research Consortium database who underwent PFD+OCF. Condylar hypoplasia was defined by an atlanto-occipital joint axis angle (AOJAA) ≥ 130°. Atlas assimilation and arch anomalies were identified on presurgical radiographic imaging. This PFD+OCF cohort was compared with a control cohort of patients who underwent PFD alone. The control group was matched to the PFD+OCF cohort according to age, sex, and duration of symptoms at a 2:1 ratio., Results: Clinical features and radiographic atlanto-occipital joint parameters were compared between 19 patients in the PFD+OCF cohort and 38 patients in the PFD-only cohort. Demographic data were not significantly different between cohorts (p > 0.05). The mean AOJAA was significantly higher in the PFD+OCF group than in the PFD group (144° ± 12° vs 127° ± 6°, p < 0.0001). In the PFD+OCF group, atlas assimilation and atlas arch anomalies were identified in 10 (53%) and 5 (26%) patients, respectively. These anomalies were absent (n = 0) in the PFD group (p < 0.001). Multivariate regression analysis identified the following 3 CVJ radiographic variables that were predictive of OCF occurrence after PFD: AOJAA ≥ 130° (p = 0.01), clivoaxial angle < 125° (p = 0.02), and occipital condyle-C2 sagittal vertical alignment (C-C2SVA) ≥ 5 mm (p = 0.01). A predictive model based on these 3 factors accurately predicted OCF following PFD (C-statistic 0.95)., Conclusions: The authors' results indicate that the occipital condyle-atlas joint complex might affect the biomechanical integrity of the CVJ in children with CM-I and syringomyelia. They describe the role of the AOJAA metric as an independent predictive factor for occurrence of OCF following PFD. Preoperative identification of these skeletal abnormalities may be used to guide surgical planning and treatment of patients with complex CM-I and coexistent osseous pathology.

Objective: Ventriculoperitoneal (VP) shunt placement requires a concurrent abdominal procedure. For peritoneal access laparoscopic or open approach may be utilized. Our aim was to compare patient/procedure characteristics and outcomes by peritoneal approach for VP shunts in children., Methods: NSQIP-Pediatric procedure targeted cerebral spinal fluid shunt Participant Use Data Files from 2016 to 2020 were queried. Patients were grouped into laparoscopic vs open abdominal approach. Patient demographics, procedure characteristics and 30-day outcomes were compared., Results: 7742 NSQIP-Pediatric patients underwent VP shunt placement. Patients undergoing laparoscopic approach were older and required less preoperative support. Mean operative time was longer with laparoscopy (mean(SD): 74.2(48.1) vs. 64.6(39) minutes, p ​< ​0.0001) but had shorter hospital LOS. There was no difference in SSI, readmissions, or reoperation rates., Conclusion: Patients undergoing laparoscopy for distal VP shunts are older with less support needs preoperatively. While laparoscopic approach had a shorter hospital LOS, there was no demonstratable difference in SSI, readmissions or reoperations between approaches. Further studies are needed to assess long-term outcomes., Competing Interests: Declaration of competing interest The authors have no conflict of interest to disclose., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Nonmissile penetrating spinal cord injury (NMPSCI) with a retained foreign body (RFB) is rare and usually results in permanent neurological deficits. In extremely rare cases, patients can present without significant neurological deficits despite an RFB that traverses the spinal canal. Given the rarity of these cases, a consensus has not yet been reached on optimal management. In a patient with an RFB and a neurologically normal clinical examination, the risk of open surgical exploration may outweigh the benefit and direct withdrawal may be a better option., Observations: A 10-year-old female suffered an NMPSCI to the thoracic spine with an RFB that bisected the spinal canal but remained neurologically intact. Direct withdrawal of the RFB was chosen instead of open surgical exploration, leading to an excellent clinical outcome. The literature was reviewed to find other examples of thoracic NMPSCI with RFB and neurologically normal examinations. Management strategies were compared., Lessons: For NMPSCI with RFB and without significant neurological deficits, direct withdrawal is a viable and possibly the best treatment option. The use of fast-acting anesthesia without intubation minimizes patient manipulation, speeds up recovery, and allows early assessment of neurological status after removal.

Background  Skull base approaches are utilized to improve microsurgical treatment of cerebral aneurysms. Advantages include early proximal and distal control, increased visualization, and minimal brain retraction. Orbitozygomatic (OZ) craniotomies via pterional incision are commonly used for the treatment of anterior communicating artery (ACoA) aneurysms. A smaller, less invasive OZ craniotomy performed through an eyebrow incision may provide several advantages over a standard OZ approach. Objective  We compare surgical outcomes of the standard and eyebrow OZ for the treatment of ACoA aneurysms. Design  All patients who underwent microsurgical treatment for ACoA aneurysms by a single surgeon over an 8-year period were included in this retrospective analysis. Patient demographics and clinical data were collected. Participants  Thirty-seven consecutive patients were identified, with 15 receiving eyebrow OZ and 22 receiving standard OZ. Main Outcome Measures Data were collected on patient demographics, pathology, intraoperative and perioperative data, and 30-day morbidity. Results  A total of 100% of the eyebrow OZ group and 95.5% of the standard OZ group had complete aneurysmal occlusion. Four eyebrow OZ and six standard OZ patients had an intraoperative rupture. All were managed without complication. Two eyebrow OZ and one standard OZ patient died within 30 days of surgery. No patients in either group had aneurysm recurrence, required retreatment, or were limited intraoperatively by exposure. Conclusions  The OZ approach via an eyebrow incision has similar outcomes to a standard OZ approach and is a safe option for the treatment of ACoA aneurysms., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Background: The occipital interhemispheric transtentorial (OITT) approach is frequently used for accessing the pineal region. There are scarce reports of using the OITT to access superior cerebellar lesions. This approach affords the patient several advantages over traditional posterior fossa approaches., Purpose: This study is to describe and evaluate clinical outcomes in a single surgeon case series of the OITT approach for pediatric patients with lesions of the superior cerebellum., Methods: All pediatric patients who underwent an OITT craniotomy for a superior cerebellar lesion by a single surgeon over a 5-year period were included in this retrospective analysis. Patient demographics and clinical data were collected., Results: Thirteen pediatric patients were identified. Cases included twelve tumors and one arteriovenous malformation. Gross total resection was achieved in 92% of cases. No patients developed posterior fossa syndrome. Two patients had transient homonymous hemianopsia that resolved by 1 month post-operatively. There were no permanent neurological deficits., Conclusion: For superomedial cerebellar lesions presenting to the tentorial surface of the superior cerebellum in patients with normal to steep tentorial angles, the OITT approach is effective and safe. This approach has a low risk of posterior fossa syndrome and permanent visual deficits when applied appropriately. Patient selection is critical for maximizing the advantages of the OITT for superior cerebellar lesions., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Pediatric basilar artery aneurysms are rare and challenging to treat. Microsurgical options and standard endovascular coiling are often undesirable choices for treatment of this pathology. Additional endovascular strategies are needed., Methods: Presentation, diagnosis, and management of pediatric basilar aneurysms were reviewed, with an emphasis on endovascular treatment strategies. Our case series of 2 patients was presented in detail, one treated with flow diversion and vessel sacrifice and one treated with stent-assisted coiling. An extensive review of the literation was performed to find other examples of pediatric basilar artery aneurysms treated with endovascular techniques., Results: Twenty-nine studies met inclusion criteria. Fifty-nine aneurysms in 58 patients were treated using endovascular techniques. Mortality rate was 10.3% (6/58) and a poor outcome (GOS 1-3) occurred in 15.5% (9/58). There were 4 reported recurrences requiring retreatment; however, only 46.5% of patients had reported follow-up of at least 1 year. 71.1% (42/59) were dissecting aneurysms., Conclusion: Basilar artery aneurysms in the pediatric population are rare, commonly giant and fusiform, and often not amenable to microsurgical or coiling techniques. The surrounding vasculature, location, size, and morphology of the aneurysm along with the durability of treatment must be considered in treatment decisions. With proper patient selection, stent-assisted coiling and flow diversion may increase the durability and safety of endovascular treatment in this population., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: The aim of this study was to determine differences in complications and outcomes between posterior fossa decompression with duraplasty (PFDD) and without duraplasty (PFD) for the treatment of pediatric Chiari malformation type I (CM1) and syringomyelia (SM)., Methods: The authors used retrospective and prospective components of the Park-Reeves Syringomyelia Research Consortium database to identify pediatric patients with CM1-SM who received PFD or PFDD and had at least 1 year of follow-up data. Preoperative, treatment, and postoperative characteristics were recorded and compared between groups., Results: A total of 692 patients met the inclusion criteria for this database study. PFD was performed in 117 (16.9%) and PFDD in 575 (83.1%) patients. The mean age at surgery was 9.86 years, and the mean follow-up time was 2.73 years. There were no significant differences in presenting signs or symptoms between groups, although the preoperative syrinx size was smaller in the PFD group. The PFD group had a shorter mean operating room time (p < 0.0001), fewer patients with > 50 mL of blood loss (p = 0.04), and shorter hospital stays (p = 0.0001). There were 4 intraoperative complications, all within the PFDD group (0.7%, p > 0.99). Patients undergoing PFDD had a 6-month complication rate of 24.3%, compared with 13.7% in the PFD group (p = 0.01). There were no differences between groups for postoperative complications beyond 6 months (p = 0.33). PFD patients were more likely to require revision surgery (17.9% vs 8.3%, p = 0.002). PFDD was associated with greater improvements in headaches (89.6% vs 80.8%, p = 0.04) and back pain (86.5% vs 59.1%, p = 0.01). There were no differences between groups for improvement in neurological examination findings. PFDD was associated with greater reduction in anteroposterior syrinx size (43.7% vs 26.9%, p = 0.0001) and syrinx length (18.9% vs 5.6%, p = 0.04) compared with PFD., Conclusions: PFD was associated with reduced operative time and blood loss, shorter hospital stays, and fewer postoperative complications within 6 months. However, PFDD was associated with better symptom improvement and reduction in syrinx size and lower rates of revision decompression. The two surgeries have low intraoperative complication rates and comparable complication rates beyond 6 months.

Background: A transition is underway in neurosurgery to perform relatively safe surgeries outpatient, often at ambulatory surgery centers (ASC). We sought to evaluate whether simple intracranial endoscopic procedures such as third ventriculostomy and cyst fenestration can be safely and effectively performed at an ASC, while comparing costs with the hospital., Methods: A retrospective chart review was performed for patients who underwent elective intracranial neuroendoscopic (NE) intervention at either a quaternary hospital or an affiliated ASC between August 2014 and September 2017. Groups were compared on length of stay, perioperative and 30-day morbidity, as well as clinical outcome at last follow-up. The total cost for these procedures were compared in relative units between all ASC cases and a small subset of hospital cases., Results: In total, 16 NE operations performed at the ASC (mean patient age 29.8 years) and 37 at the hospital (mean age 15.4 years) with average length of stay of 3.5 hours and 23.1 hours respectively (P < 0.05). There were no acute complications in either cohort or morbid events requiring hospitalization within 30 days. Surgical success was noted for 75% of the ASC patients and 73% of the hospital cohort. The mean cost of 5 randomly selected hospital operations with same-day discharge and 5 with overnight stay was 3.4 and 4.1 times that of the ASC cohort, respectively (P < 0.05)., Conclusions: Elective endoscopic third ventriculostomy and other simple NE procedures can be safely and effectively performed at an ASC for appropriate patients with significantly reduced cost compared with the hospital., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background  The eyebrow orbitozygomatic craniotomy is a minimally invasive approach that can access a wide variety of lesions. Unintentional breach of the frontal sinus frequently occurs and has been cited as a reason to avoid this approach. Lack of access to a large pericranial graft and the inability to completely cranialize the sinus requires alternate techniques of sinus repair. We describe a technique for repairing an opened frontal sinus and retrospectively reviewed complications related to this approach. Methods  All patients, who underwent an orbitozygomatic craniotomy via an eyebrow incision by a single surgeon from August 1, 2012 to August 31, 2018, were included in this retrospective analysis. Data were collected on patient demographics, pathology treated, operative details, and perioperative morbidity. Follow-up ranged from 6 weeks to 6 years. Results  Total 50 patients with a wide variety of pathologies underwent analysis. Frontal sinus breach occurred in 21 patients. All were repaired by the described technique. One patient (ruptured aneurysm) had a suspected cerebrospinal fluid (CSF) leak postoperatively that resolved without any additional intervention. One patient developed a pneumomeningocele 4 years postoperatively that required reoperation. No patient suffered any infection or delayed CSF leak. Conclusion  Breach of the frontal sinus is common during eyebrow craniotomies. Despite reduced options for local repair, these patients have experienced no CSF leaks requiring intervention and no infections in our series. Long-term mucocele risk is not reliably determined with our length of follow-up. Breach of the frontal sinus is not a contraindication to the eyebrow approach., Competing Interests: Conflict of Interest S.D.W. reports personal fees from Integra, outside the submitted work. All the other authors report no conflict of interest., (Thieme. All rights reserved.)

Objective: Scoliosis is common in patients with Chiari malformation type I (CM-I)-associated syringomyelia. While it is known that treatment with posterior fossa decompression (PFD) may reduce the progression of scoliosis, it is unknown if decompression with duraplasty is superior to extradural decompression., Methods: A large multicenter retrospective and prospective registry of 1257 pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for patients with scoliosis who underwent PFD with or without duraplasty., Results: In total, 422 patients who underwent PFD had a clinical diagnosis of scoliosis. Of these patients, 346 underwent duraplasty, 51 received extradural decompression alone, and 25 were excluded because no data were available on the type of PFD. The mean clinical follow-up was 2.6 years. Overall, there was no difference in subsequent occurrence of fusion or proportion of patients with curve progression between those with and those without a duraplasty. However, after controlling for age, sex, preoperative curve magnitude, syrinx length, syrinx width, and holocord syrinx, extradural decompression was associated with curve progression > 10°, but not increased occurrence of fusion. Older age at PFD and larger preoperative curve magnitude were independently associated with subsequent occurrence of fusion. Greater syrinx reduction after PFD of either type was associated with decreased occurrence of fusion., Conclusions: In patients with CM-I, syrinx, and scoliosis undergoing PFD, there was no difference in subsequent occurrence of surgical correction of scoliosis between those receiving a duraplasty and those with an extradural decompression. However, after controlling for preoperative factors including age, syrinx characteristics, and curve magnitude, patients treated with duraplasty were less likely to have curve progression than patients treated with extradural decompression. Further study is needed to evaluate the role of duraplasty in curve stabilization after PFD.

Objective: Posterior fossa decompression with duraplasty (PFDD) is commonly performed for Chiari I malformation (CM-I) with syringomyelia (SM). However, complication rates associated with various dural graft types are not well established. The objective of this study was to elucidate complication rates within 6 months of surgery among autograft and commonly used nonautologous grafts for pediatric patients who underwent PFDD for CM-I/SM., Methods: The Park-Reeves Syringomyelia Research Consortium database was queried for pediatric patients who had undergone PFDD for CM-I with SM. All patients had tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and ≥ 6 months of postoperative follow-up after PFDD. Complications (e.g., pseudomeningocele, CSF leak, meningitis, and hydrocephalus) and postoperative changes in syrinx size, headaches, and neck pain were compared for autograft versus nonautologous graft., Results: A total of 781 PFDD cases were analyzed (359 autograft, 422 nonautologous graft). Nonautologous grafts included bovine pericardium (n = 63), bovine collagen (n = 225), synthetic (n = 99), and human cadaveric allograft (n = 35). Autograft (103/359, 28.7%) had a similar overall complication rate compared to nonautologous graft (143/422, 33.9%) (p = 0.12). However, nonautologous graft was associated with significantly higher rates of pseudomeningocele (p = 0.04) and meningitis (p < 0.001). The higher rate of meningitis was influenced particularly by the higher rate of chemical meningitis (p = 0.002) versus infectious meningitis (p = 0.132). Among 4 types of nonautologous grafts, there were differences in complication rates (p = 0.02), including chemical meningitis (p = 0.01) and postoperative nausea/vomiting (p = 0.03). Allograft demonstrated the lowest complication rates overall (14.3%) and yielded significantly fewer complications compared to bovine collagen (p = 0.02) and synthetic (p = 0.003) grafts. Synthetic graft yielded higher complication rates than autograft (p = 0.01). Autograft and nonautologous graft resulted in equal improvements in syrinx size (p < 0.0001). No differences were found for postoperative changes in headaches or neck pain., Conclusions: In the largest multicenter cohort to date, complication rates for dural autograft and nonautologous graft are similar after PFDD for CM-I/SM, although nonautologous graft results in higher rates of pseudomeningocele and meningitis. Rates of meningitis differ among nonautologous graft types. Autograft and nonautologous graft are equivalent for reducing syrinx size, headaches, and neck pain.

Background: Occipital-cervical fusion (OCF) and ventral decompression (VD) may be used in the treatment of pediatric Chiari-1 malformation (CM-1) with syringomyelia (SM) as adjuncts to posterior fossa decompression (PFD) for complex craniovertebral junction pathology., Objective: To examine factors influencing the use of OCF and OCF/VD in a multicenter cohort of pediatric CM-1 and SM subjects treated with PFD., Methods: The Park-Reeves Syringomyelia Research Consortium registry was used to examine 637 subjects with cerebellar tonsillar ectopia ≥ 5 mm, syrinx diameter ≥ 3 mm, and at least 1 yr of follow-up after their index PFD. Comparisons were made between subjects who received PFD alone and those with PFD + OCF or PFD + OCF/VD., Results: All 637 patients underwent PFD, 505 (79.2%) with and 132 (20.8%) without duraplasty. A total of 12 subjects went on to have OCF at some point in their management (PFD + OCF), whereas 4 had OCF and VD (PFD + OCF/VD). Of those with complete data, a history of platybasia (3/10, P = .011), Klippel-Feil (2/10, P = .015), and basilar invagination (3/12, P < .001) were increased within the OCF group, whereas only basilar invagination (1/4, P < .001) was increased in the OCF/VD group. Clivo-axial angle (CXA) was significantly lower for both OCF (128.8 ± 15.3°, P = .008) and OCF/VD (115.0 ± 11.6°, P = .025) groups when compared to PFD-only group (145.3 ± 12.7°). pB-C2 did not differ among groups., Conclusion: Although PFD alone is adequate for treating the vast majority of CM-1/SM patients, OCF or OCF/VD may be occasionally utilized. Cranial base and spine pathologies and CXA may provide insight into the need for OCF and/or OCF/VD., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Background: Traumatic tension pneumocephalus is a rare complication after craniofacial fractures that can cause devastating neurologic deficits if not managed promptly and effectively., Case Report: A 38-year-old man with no past medical history presented to the Emergency Department (ED) after a motor vehicle crash. He was noted to have an open frontal scalp laceration. Computed tomography (CT) revealed a right frontal subdural hematoma and right medial frontal contusion. There was also a frontal bone fracture extending through the frontal sinus with mild underlying pneumocephalus. He was monitored for cerebrospinal fluid (CSF) leak and was subsequently discharged on postinjury day 9. He re-presented to the ED 14 days post injury with lethargy, confusion, headache, and swelling around his scalp laceration. A CT scan was obtained that revealed a large-volume intraparenchymal pneumocephalus (pneumocerebri) with mass effect and midline shift. The patient was started on 100% oxygen and admitted to the intensive care unit. He was taken to the operating room for evacuation of the pneumocerebri, repair of dural defect, placement of a vascularized pericranial graft, and placement of a lumbar drain. His lumbar drain was removed on postoperative day 3 and he was discharged home neurologically intact on postoperative day 6. At 1 month follow-up he had no evidence of CSF leak and was neurologically intact. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case is presented to increase awareness among emergency physicians that traumatic tension pneumocephalus, and in this case, pneumocerebri, is a rare life-threatening neurosurgical emergency in patients with severe craniofacial fractures after blunt or penetrating head trauma. Early temporizing measures in the ED, such as 100% oxygen via nonrebreather face mask, and urgent neurosurgical consultation are indicated to prevent neurologic deterioration., (Published by Elsevier Inc.)

Background: Endoscopic third ventriculostomy (ETV) is an effective primary treatment for certain forms of hydrocephalus. However, its use in children with an existing shunt is less well known., Objective: To report a multicenter experience in attempting to convert patients from shunt dependence to a third ventriculostomy and to determine predictors of success., Methods: Three participating centers provided retrospectively collected information on patients with an attempted conversion from a shunt to an ETV between December 1, 2008, and April 1, 2018. Demographic, clinical, and radiological data were recorded. Success was defined as shunt independence at the last follow-up., Results: Eighty patients with an existing ventricular shunt underwent an ETV. The median age at the time of the index ETV was 9.9 yr, and 44 (55%) patients were male. The overall success rate was 64% (51/80), with a median duration of follow-up of 2.0 yr (range, 0.1-9.4 yr). Four patients required a successful repeat ETV at a median of 1.7 yr (range, 0.1-5.7 yr) following the index ETV. Only age was predictive of ETV failure on multivariate analysis (odds ratio 0.86 [95% CI 0.78-0.94], P = .005). No patient less than 6 mo of age underwent an ETV, and of the 5 patients between 6 and 12 mo of age, 4 failed., Conclusion: Although not every shunted patient will be a candidate for an ETV, nor will they be successfully converted, an ETV should at least be considered in every child who presents with a shunt malfunction or who has an externalized shunt., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Objective: Factors associated with syrinx size in pediatric patients undergoing posterior fossa decompression (PFD) or PFD with duraplasty (PFDD) for Chiari malformation type I (CM-I) with syringomyelia (SM; CM-I+SM) are not well established., Methods: Using the Park-Reeves Syringomyelia Research Consortium registry, the authors analyzed variables associated with syrinx radiological outcomes in patients (< 20 years old at the time of surgery) with CM-I+SM undergoing PFD or PFDD. Syrinx resolution was defined as an anteroposterior (AP) diameter of ≤ 2 mm or ≤ 3 mm or a reduction in AP diameter of ≥ 50%. Syrinx regression or progression was defined using 1) change in syrinx AP diameter (≥ 1 mm), or 2) change in syrinx length (craniocaudal, ≥ 1 vertebral level). Syrinx stability was defined as a < 1-mm change in syrinx AP diameter and no change in syrinx length., Results: The authors identified 380 patients with CM-I+SM who underwent PFD or PFDD. Cox proportional hazards modeling revealed younger age at surgery and PFDD as being independently associated with syrinx resolution, defined as a ≤ 2-mm or ≤ 3-mm AP diameter or ≥ 50% reduction in AP diameter. Radiological syrinx resolution was associated with improvement in headache (p < 0.005) and neck pain (p < 0.011) after PFD or PFDD. Next, PFDD (p = 0.005), scoliosis (p = 0.007), and syrinx location across multiple spinal segments (p = 0.001) were associated with syrinx diameter regression, whereas increased preoperative frontal-occipital horn ratio (FOHR; p = 0.007) and syrinx location spanning multiple spinal segments (p = 0.04) were associated with syrinx length regression. Scoliosis (HR 0.38 [95% CI 0.16-0.91], p = 0.03) and smaller syrinx diameter (5.82 ± 3.38 vs 7.86 ± 3.05 mm; HR 0.60 [95% CI 0.34-1.03], p = 0.002) were associated with syrinx diameter stability, whereas shorter preoperative syrinx length (5.75 ± 4.01 vs 9.65 ± 4.31 levels; HR 0.21 [95% CI 0.12-0.38], p = 0.0001) and smaller pB-C2 distance (6.86 ± 1.27 vs 7.18 ± 1.38 mm; HR 1.44 [95% CI 1.02-2.05], p = 0.04) were associated with syrinx length stability. Finally, younger age at surgery (8.19 ± 5.02 vs 10.29 ± 4.25 years; HR 1.89 [95% CI 1.31-3.04], p = 0.01) was associated with syrinx diameter progression, whereas increased postoperative syrinx diameter (6.73 ± 3.64 vs 3.97 ± 3.07 mm; HR 3.10 [95% CI 1.67-5.76], p = 0.003), was associated with syrinx length progression. PFD versus PFDD was not associated with syrinx progression or reoperation rate., Conclusions: These data suggest that PFDD and age are independently associated with radiological syrinx improvement, although forthcoming results from the PFDD versus PFD randomized controlled trial (NCT02669836, clinicaltrials.gov) will best answer this question.

Benign intracranial cystic lesions of the thalamus are an uncommon clinical entity rarely requiring operative decompression. In combination with cyst fenestration, cerebrospinal fluid (CSF) flow diversion or fenestrated stent placement may be performed at the time of surgery. We describe a method of treatment of these cysts using endoscopic cyst fenestration with fenestrated transventricular stent placement. Three patients with benign cystic lesions were treated with stereotactic-guided, endoscopic fenestration and fenestrated stent placement. All 3 had radiographic and clinical improvement. There were no complications. Endoscopic fenestration and transventricular fenestrated stent placement is a minimally invasive, effective, and safe method to decompress benign, symptomatic cystic lesions of the thalamus., (Copyright © 2019. Published by Elsevier Ltd.)

Objective: Scoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors' goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis., Methods: A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°)., Results: Based on available imaging of patients with CM-I and syrinx, 260 of 825 patients (31%) had a clear diagnosis of scoliosis based on radiographs or coronal MRI. Forty-nine patients (5.9%) did not have scoliosis, and in 516 (63%) patients, a clear determination of the presence or absence of scoliosis could not be made. Comparison of patients with and those without a definite scoliosis diagnosis indicated that scoliosis was associated with wider syrinxes (8.7 vs 6.3 mm, OR 1.25, p < 0.001), longer syrinxes (10.3 vs 6.2 levels, OR 1.18, p < 0.001), syrinxes with their rostral extent located in the cervical spine (94% vs 80%, OR 3.91, p = 0.001), and holocord syrinxes (50% vs 16%, OR 5.61, p < 0.001). Multivariable regression analysis revealed syrinx length and the presence of holocord syrinx to be independent predictors of scoliosis in this patient cohort. Scoliosis was not associated with sex, age at CM-I diagnosis, tonsil position, pB-C2 distance (measured perpendicular distance from the ventral dura to a line drawn from the basion to the posterior-inferior aspect of C2), clivoaxial angle, or frontal-occipital horn ratio. Average curve magnitude was 29.9°, and 37.7% of patients had a left thoracic curve. Older age at CM-I or syrinx diagnosis (p < 0.0001) was associated with greater curve magnitude whereas there was no association between syrinx dimensions and curve magnitude., Conclusions: Syrinx characteristics, but not tonsil position, were related to the presence of scoliosis in patients with CM-I, and there was an independent association of syrinx length and holocord syrinx with scoliosis. Further study is needed to evaluate the nature of the relationship between syrinx and scoliosis in patients with CM-I.

Background: Stereotactic radiosurgery (SRS) is an increasingly common modality used with surgery for resectable brain metastases (BM)., Objective: To present a multi-institutional retrospective comparison of outcomes and toxicities of preoperative SRS (Pre-SRS) and postoperative SRS (Post-SRS)., Methods: We reviewed the records of patients who underwent resection of BM and either Pre-SRS or Post-SRS alone between 2005 and 2013 at 2 institutions. Pre-SRS used a dose-reduction strategy based on tumor size, with planned resection within 48 hours. Cumulative incidence with competing risks was used to determine estimated rates., Results: A total of 180 patients underwent surgical resection for 189 BM: 66 (36.7%) underwent Pre-SRS and 114 (63.3%) underwent Post-SRS. Baseline patient characteristics were balanced except for higher rates of performance status 0 (62.1% vs 28.9%, P < .001) and primary breast cancer (27.2% vs 10.5%, P = .010) for Pre-SRS. Pre-SRS had lower median planning target volume margin (0 mm vs 2 mm) and peripheral dose (14.5 Gy vs 18 Gy), but similar gross tumor volume (8.3 mL vs 9.2 mL, P = .85). The median imaging follow-up period was 24.6 months for alive patients. Multivariable analyses revealed no difference between groups for overall survival (P = .1), local recurrence (P = .24), and distant brain recurrence (P = .75). Post-SRS was associated with significantly higher rates of leptomeningeal disease (2 years: 16.6% vs 3.2%, P = .010) and symptomatic radiation necrosis (2 years: 16.4% vs 4.9%, P = .010)., Conclusion: Pre-SRS and Post-SRS for resected BM provide similarly favorable rates of local recurrence, distant brain recurrence, and overall survival, but with significantly lower rates of symptomatic radiation necrosis and leptomeningeal disease in the Pre-SRS cohort. A prospective clinical trial comparing these treatment approaches is warranted., Abbreviations: BM, brain metastasesCI, confidence intervalCTV, clinical target volumeDBR, distant brain recurrenceGTV, gross tumor volumeLC, local controlLMD, leptomeningeal diseaseLR, local recurrenceMVA, multivariable analysisOS, overall survivalPost-SRS, postoperative stereotactic radiosurgeryPre-SRS, preoperative stereotactic radiosurgeryPTV, planning target volumeRN, radiation necrosisSRN, symptomatic radiation necrosisSRS, stereotactic radiosurgeryWBRT, whole-brain radiation therapy.

Glioblastoma (GBM) remains an almost universally fatal diagnosis. The current therapeutic mainstay consists of maximal safe surgical resection followed by radiation therapy (RT) with concomitant temozolomide (TMZ), followed by monthly TMZ (the "Stupp regimen"). Several chemotherapeutic agents have been shown to have modest efficacy in the treatment of high-grade glioma (HGG), but blood-brain barrier impermeability remains a major delivery obstacle. Polymeric drug-delivery systems, developed to allow controlled local release of biologically active substances for a variety of conditions, can achieve high local concentrations of active agents while limiting systemic toxicities. Polymerically delivered carmustine (BCNU) wafers, placed on the surface of the tumor-resection cavity, can potentially provide immediate chemotherapy to residual tumor cells during the standard delay between surgery and chemoradiotherapy. BCNU wafer implantation as monochemotherapy (with RT) in newly diagnosed HGG has been investigated in 2 phase III studies that reported significant increases in median overall survival. A number of studies have investigated the tumoricidal synergies of combination chemotherapy with BCNU wafers in newly diagnosed or recurrent HGG, and a primary research focus has been the integration of BCNU wafers into multimodality therapy with the standard Stupp regimen. Overall, the results of these studies have been encouraging in terms of safety and efficacy. However, the data must be qualified by the nature of the studies conducted. Currently, there are no phase III studies of BCNU wafers with the standard Stupp regimen. We review the rationale, biochemistry, pharmacokinetics, and research history (including toxicity profile) of this modality., (© The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Object: Patients who develop a lower-extremity neurological deficit after lumbar laminectomy present a diagnostic dilemma. In the setting of a neurological deficit, some surgeons use MRI to evaluate for symptomatic compression of the thecal sac. The authors conducted a prospective observational cohort study in patients undergoing open lumbar laminectomy for neurogenic claudication to document the MRI appearance of the postlaminectomy spine and to determine changes in thecal sac diameter caused by the accumulation of epidural fluid., Methods: Eligible patients who were candidates for open lumbar laminectomy for neurogenic claudication at a single neurosurgical center between August 2007 and June 2009 were enrolled. Preoperative and postoperative MRI of the lumbar spine was performed on the same MRI scanner. Postoperative MRI studies were completed within 36 hours of surgery. Routine clinical and surgical data were collected at the preoperative visit, during surgery, and postoperatively. Images were interpreted for the signal characteristics of the epidural fluid and for thecal diameter (region of interest [ROI]) by 2 blinded neuroradiologists., Results: Twenty-four patients (mean age 69.7 years, range 30-83 years) were enrolled, and 20 completed the study. Single-level laminectomy was performed in 6 patients, 2-level in 12, and 3-level in 2. Preoperative canal measurements (ROI) at the most stenotic level averaged 0.26 cm(2) (range 0.0-0.46 cm(2)), and postoperative ROI at that same level averaged 0.95 cm(2) (range 0.46-2.05 cm(2)). The increase in ROI averaged 0.69 cm(2) (range 0.07-1.81 cm(2)). Seven patients (35%) had immediate postoperative weakness in at least 1 muscle group graded at 4+/5. The decline in examination was believed to be effort dependent and secondary to discomfort in the acute postoperative period. Those with weakness had smaller increases in ROI (0.51 cm(2)) than those with full strength (0.78 cm(2), p = 0.1599), but none had evidence of worsened thecal compression. On the 1st postoperative day, 19 patients were at full strength and all patients were at full strength at their 15-day follow-up. The T1-weighted epidural fluid signal was isointense in 19 of the 20 patients. The T2-weighted epidural fluid signal was hyperintense in 9, isointense in 4, and hypointense in 7 patients., Conclusions: Immediately after lumbar laminectomy, the appearance of the thecal sac on MRI can vary widely. In most patients the thecal sac diameter increases after laminectomy despite the presence of epidural blood. In this observational cohort, a reduction in thecal diameter caused by epidural fluid did not correlate with motor function. Results in the small subset of patients where the canal diameter decreased due to epidural fluid compression of the thecal sac raises the question of the utility of immediate postoperative MRI.

Objective: Human hypothalamic hamartomas (HH) are intrinsically epileptogenic and are associated with treatment-resistant gelastic seizures. The basic cellular mechanisms responsible for seizure onset within HH are unknown. We used intra-operative microwire recordings of single neuron activity to measure the spontaneous firing rate of neurons and the degree of functional connection between neurons within the tumor., Technique: Fourteen patients underwent transventricular endoscopic resection of HH for treatment-resistant epilepsy. Prior to surgical resection, single neuron recordings from bundled microwires (total of nine contacts) were obtained from HH tissue. Spontaneous activity was recorded for two or three 5-min epochs under steady-state general anesthesia. Off-line analysis included cluster analysis of single unit activity and probability analysis of firing relationships between pairs of neurons., Results: Altogether, 222 neurons were identified (mean 6 neurons per recording epoch). Cluster analysis of single neuron firing utilizing a mixture of Gaussians model identified two distinct populations on the basis of firing rate (median firing frequency 0.6 versus 15.0 spikes per second; p < 10(-5)). Cluster analysis identified three populations determined by levels of burst firing (median burst indices of 0.015, 0.18, and 0.39; p < 10(-15)). Unbiased analysis of spontaneous single unit behavior showed that 51% of all possible neuron pairs within each recording epoch had a significant level of firing synchrony (p < 10(-15)). The subgroup of neurons with higher median firing frequencies was more likely to demonstrate synchronous firing (p < 10(-7))., Conclusion: Hypothalamic hamartoma tissue in vivo contains neurons which fire spontaneously. The activity of single neurons is diverse but distributes into at least two electrophysiological phenoytpes. Functional linkage between single neurons suggests that HH neurons exist within local networks that may contribute to ictogenesis.

Objective: Endoscopic approaches are increasingly utilized to treat third ventricular colloid cysts but have been associated with lower rates of complete cyst wall resection. Our objective was to assess the results of colloid cyst resection via an anterolateral endoscopic approach with a dual-instrument technique, with an emphasis on completeness of cyst wall resection., Methods: A retrospective review of the senior author's experience with 22 colloid cysts treated with endoscopic resection since 2004 was performed. Initial cyst size, completeness of resection, postoperative radiographic residual, recurrence at follow-up, need for reoperation, and neurologic morbidity were assessed. All cysts were approached from an anterolateral trajectory with two instruments working in concert through a single endoscope., Results: Of 22 patients, near-total resection was obtained in 95%. In 3 cases, a very small, radiographically occult residual was left. Complete cyst wall resection was therefore obtained in 18 (82%). There were no cases of recurrence at follow-up in any patient. No patients required craniotomy or underwent re-resection. Fifteen of 16 (94%) patients with long-term clinical follow-up remained stable or improved., Conclusion: High rates of complete colloid cyst resection, with low morbidity, are possible with an anterolateral endoscopic approach with dual-instrument technique. These results support the findings of other endoscopists that show how technical modifications to traditional endoscopic approaches can produce favorable results., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: The absence of ventriculomegaly has been considered an overt or relative contraindication to the endoscopic resection of colloid cysts. In the past, endoscopic removal of colloid cysts in the absence of ventriculomegaly has been considered ill advised. Reports of successful endoscopic surgery in small ventricles are surfacing., Objective: We examined the combined experience of 2 high-volume endoscopic centers to characterize the outcomes of patients undergoing endoscopic removal of colloid cysts in small ventricles., Methods: We retrospectively reviewed all endoscopic colloid cyst removal procedures by the 2 senior authors (P.N., C.T.) performed at the Barrow Neurological Institute over an 8-year period. Radiographic, clinical, and interview data were recorded and analyzed. The age-adjusted relative bicaudate index was used to define small ventricles., Results: Sixteen patients (8 female) underwent attempted endoscopic removal of a colloid cyst in the absence of ventriculomegaly. Surgery was technically successful in 15 patients. The cyst was removed completely in 13 of patients. Short-term memory loss was initially present in 3 patients and completely resolved in all but 1 patient who had presented with short-term memory loss. Temporary complications occurred in 2 patients., Conclusion: Normal-size ventricles are not a contraindication to endoscopic removal of third ventricular colloid cysts. Complication rates are at least comparable to those of patients with ventriculomegaly or to those undergoing open microsurgical resection.

Neurocutaneous melanosis (NCM) is a rare, congenital neuroectodermal dysplasia generally resulting in early death from neurological decline due to leptomeningeal involvement. Nonmeningeal CNS epileptogenic lesions presenting in later childhood in the absence of leptomeningeal disease are rare. This report summarizes a rare presentation and curative epilepsy surgery. The authors discuss the case of a 14-year-old girl with NCM who originally presented with intractable partial-onset seizures. The MRI, PET, and SPECT studies subsequently revealed a focal epileptogenic source in the right temporal lobe. Results of video-electroencephalography monitoring concurred with the imaging findings, and a right temporal lobectomy was performed including the medial structures. Following surgery, histopathological features of the lesion included multiple scattered mononuclear cells with brown pigmentation in the amygdala specimen. The patient remains seizure free 2 years postresection, and no longer needs medication for seizure management. This patient presented with an atypical CNS manifestation of NCM that is curable by epilepsy surgery. Her intractable epilepsy developed secondary to amygdalar neuromelanosis, which had no associated leptomeningeal melanosis, an uncommon occurrence. As evidenced by the lack of seizure activity following resection, the patient's quality of life greatly improved after neurological surgery.

Object: Advances in brain imaging have allowed for more sophisticated mapping of crucial neural structures. Functional MRI (fMRI) measures local changes in blood oxygenation associated with changes in neural activity and is useful in mapping cortical activation. Applications of this imaging modality have generally been restricted to cooperative patients; however, fMRI has proven successful in localizing the motor cortex for neurosurgical planning in uncooperative children under sedation. The authors demonstrate that the use of fMRI to localize the visual cortex in sedated children can be safely and effectively performed, allowing for more accurate presurgical planning to spare visual structures., Methods: Between 2007 and 2009, 11 children (age range 1-11 years) underwent fMRI for neurosurgical planning while under sedation. Blood oxygen level-dependent fMRI was performed to detect visual cortex activation during stimulation through closed eyelids. Visual stimulation was presented in block design with periods of flashing light alternated with darkness., Results: Functional MRI was successful in identifying visual cortex in each of the 11 children tested. There were no complications with propofol sedation or the fMRI. All children suffered from epilepsy, 5 had brain tumors, and 1 had tuberous sclerosis. After fMRI was performed, 6 patients underwent surgery. Frameless stereotactic guidance was synchronized with fMRI data to design an approach to spare visual structures during resection. There were no cases where a false negative led to unexpected visual field deficits or other side effects of surgery. In 2 cases, the fMRI results demonstrated that the tracts were already disrupted: in one case from a prior tumor operation and in another from dysplasia., Conclusions: Functional MRI for evaluation of visual pathways can be safely and reproducibly performed in young or uncooperative children under light sedation. Identification of primary visual cortex aids in presurgical planning to avoid vision loss in appropriately selected patients.

Introduction: Pediatric patients harboring shunts placed early in life are subjected to numerous radiographic studies during development of their central nervous system. Radiation is detrimental to these young patients. MRI avoids the risk of radiation but is thought more difficult due to the increased time a young patient must lie motionless during scan acquisition. Optimal radiographic interrogation would be quick, radiation-free, and allow adequate ventricular evaluation., Methods: We queried the electronic medical records system of the senior author (SE) for the terms "hydrocephalus" and "shunt malfunction." All patients currently younger than 18 years were included. In the last 5 years, pediatric patients have been evaluated in an office setting with a limited MRI sequence (T1 sagittal, T2 axial, T1 axial, and DWI) lasting a total of 178 s. In the event of significant motion artifact, the total sequence is abandoned and an 8-s T2 diffusion-weighted scan is performed., Results: Forty-four patients were included in the study (20 males, average age 10.4 yrs). Eighty-eight rapid acquisition scans were obtained. Adequate ventricular evaluation was performed without sedation in every case. In each instance where there was motion, the 8-s scan provided adequate ventricular evaluation., Conclusion: Rapid acquisition MRI scanning avoids the deleterious cumulative effects of radiation in pediatric patients and allows adequate evaluation of the ventricles without the need for sedation.

Objective: Tanzania suffers from a severe lack of health practitioners trained in neurosurgical procedures. To address this problem, we have implemented an initiative, modeled after the experience of other pioneers in international neurosurgery, to establish cost-effective and sustainable neurosurgical care by teaching fundamental neurosurgical skills to local surgeons. In this report we describe our early experience in Northwest Tanzania and discuss the potential for this training model to improve neurosurgical care to a region in need., Methods: Between September 2009 and October 2010, three residents and two attendings from our institution spent a total of 15 weeks at Bugando Medical Centre in Mwanza, Tanzania. During this time, we focused on teaching neurosurgical techniques, intraoperative decision-making, and clinical management skills to two local surgeons. The emphasis of our presence was on teaching and providing sustainable neurosurgical care., Results: During this period, we performed 41 neurosurgical procedures with one of two local surgeons. The most common procedures performed were ventriculoperitoneal shunts (22%), myelomeningocele repairs (22%), and cranial trauma cases (17%). Five (12%) cases required the placement of spinal instrumentation. Thirty-nine (95%) patients remained stable or improved at discharge. There were 2 (5%) perioperative deaths., Conclusion: Although numerous challenges remain, our experience demonstrates the potential of this teaching model in providing sustainable neurosurgical care in Northwest Tanzania., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Study Design: Retrospective review of a prospectively maintained surgical database., Objective: To report the indications, surgical procedures performed, and outcomes from the largest series of thoracoscopically treated herniated thoracic discs (HTDs). We also compared approach-related complications with an unmatched cohort undergoing thoracotomy for HTD., Summary of Background Data: Symptomatic HTDs are rare, and their surgical management is technically challenging., Methods: A prospectively maintained surgical database of all patients undergoing surgery for symptomatic HTDs by the senior author (blinded for review) was reviewed. As needed, the database was supplemented with hospital and clinic charts and telephone conversations with patients. A triportal method of thoracoscopic discectomy was performed in all cases., Results: Between 1994 and 2008, 121 patients underwent 125 thoracoscopic-assisted operations for 139 HTDs. Their mean age at surgery was 46.6 years. Indications for thoracoscopic resection currently include small symptomatic disc, anterior location, nonmorbidly obese patient, favorable chest anatomy, and T4-T11 location. Symptom duration averaged 32 months. Radiculopathy was the most common presentation, followed by myelopathy and pain (radiculopathic or back). The mean hospital stay was 4.8 days. Chest tubes remained in place for a mean of 3.2 days. At a mean follow-up of 2.4 years, myelopathy, radiculopathy, and back pain had resolved or improved at a rate of 91.1%, 97.6%, and 86.5%, respectively. Patients reported worsening in 0%, 1.2%, and 0% of cases, respectively. Most patients (97.4%) would be willing to undergo the operation again. The complication rate was acceptable. Patients undergoing thoracoscopic excision had less approach-related morbidity than an unmatched cohort undergoing excision using thoracotomy., Conclusion: Thoracoscopic-assisted microsurgical resection is a safe, effective, and minimally invasive method of treating symptomatic HTDs in appropriately selected patients. The symptoms of most patients improve or resolve with minimal morbidity.

Background: The retrosigmoid approach is often used for posterior fossa pathology. Many variations of positioning exist. Here, we report a simple, safe, and quick positioning technique which maximizes patient safety, surgeon comfort, and intraoperative view., Methods: We reviewed the senior author's prospective surgical database for retrosigmoid approaches to the posterior fossa and noted any complications or difficult exposures., Results: Over 970 retrosigmoid operations were performed over the course of 19 years. There were no positioning-related complications and no aborted surgeries due to inadequate exposure. No normal cerebellum was ever resected to increase exposure and no retractor was ever used in the posterior fossa., Conclusions: Supine positioning for the retrosigmoid approach is an excellent and safe positioning alternative., (Georg Thieme Verlag KG Stuttgart · New York.)

Introduction: Neurenteric cysts are a rare cause of central nervous system compression. Pediatric intracranial cysts are even less common., Case Study: We describe the presentation, imaging features, surgical management, and postoperative course of a 5-year-old female with congenital third nerve paresis, worsening headaches, and a cyst of the third nerve. We performed an eyebrow incision and keyhole supraorbital craniotomy for exploration and subsequent resection of a neurenteric cyst that was densely involved with the third nerve at its exit from the midbrain. Postoperatively, she had chemical meningitis and complete third nerve palsy. This entity is extremely rare in this location but should be included in the differential. We summarize the current literature on these lesions and recommend biopsy and fenestration as surgical treatment.

Object: Thoracoscopy may be used in place of thoracotomy to resect intrathoracic neoplasms such as paraspinal neurogenic tumors. Although these tumors are rare, they account for the majority of tumors arising in the posterior mediastinum., Methods: A database was maintained of all patients undergoing thoracoscopic surgery for tumors. The authors analyzed the presenting symptoms, pathological diagnoses, and outcomes of 26 patients (7 males and 19 females, mean age 37.2 years) who were treated for intrathoracic tumors via thoracoscopy between January 1995 and May 2009. Fourteen patients were diagnosed incidentally (54%). Five patients (19%) presented with dyspnea or shortness of breath, 4 (15%) with pain, 1 (4%) with pneumonia, 1 (4%) with hoarseness, and 1 (4%) with Horner syndrome., Results: Pathology demonstrated schwannomas in 20 patients (77%). Other diagnoses included ganglioneurofibroma, paraganglioma, epithelioid angiosarcoma, benign hemangioma, benign granular cell tumor, and infectious granuloma. One patient required conversion to open thoracotomy due to pleural scarring to the tumor. One underwent initial laminectomy due to intraspinal extension of the tumor. Gross-total resection was obtained in 25 cases (96%). The remaining patient underwent biopsy followed by radiation therapy. The mean surgical time was 2.5 hours, and the mean blood loss was 243 ml. The mean duration of chest tube insertion was 1.3 days, and the mean length of hospital stay was 3.0 days. Cases that were treated in the second half of the cohort were more often diagnosed incidentally, performed in less time, and had less blood loss than those in the first half of the cohort. There was 1 case of permanent treatment-related morbidity (mild Horner syndrome). All previously employed patients were able to return to work (mean clinical follow-up 43 months). There were no recurrences (mean imaging follow-up 54 months)., Conclusions: Endoscopic transthoracic approaches can reduce approach-related soft-tissue morbidity and facilitate recovery by preserving the normal tissues of the chest wall, by avoiding rib retraction and muscle transection, and by reducing postoperative pain. This less invasive approach thus shortens hospital stay and recovery time.

Background: Spinal dural arteriovenous fistulae (dAVFs), are lesions involving an aberrant connection between a radicular feeding artery and the venous system of the spinal cord at the dural sleeve of the nerve root. When rare dAVFs are occult on digitally subtracted catheter-based angiography, they present a diagnostic and therapeutic challenge., Objective: We report 3 cases of angiographically occult spinal dAVFs that were evaluated during surgery with indocyanine green (ICG) fluorescent microscope-integrated angiography., Methods: Three patients with clinical and magnetic resonance imaging features suggestive of a spinal dAVF but no abnormality on digital subtraction angiography underwent surgical exploration with the aid of microscope-integrated ICG videoangiography., Results: In all 3 cases, ICG identified the intradural vein draining the fistula, clearly distinguishing it from an artery or uninvolved medullary vein., Conclusion: ICG angiography can rapidly identify a draining vein as it enters the spinal canal even in dAVFs not identifiable on catheter-based digital subtraction angiography.

Object: The aim of this study was to clarify the surgical indications, risks, and long-term clinical outcomes associated with the use of deep hypothermic circulatory arrest for the surgical treatment of intracranial aneurysms., Methods: The authors retrospectively reviewed 105 deep hypothermic circulatory arrest procedures performed in 103 patients (64 females and 39 males, with a mean age of 44.8 years) to treat 104 separate aneurysms. Patients' clinical histories, radiographs, and operative reports were evaluated. There were 97 posterior circulation aneurysms: at the basilar apex in 60 patients, midbasilar artery in 21, vertebrobasilar junction in 11, superior cerebellar artery in 4, and posterior cerebral artery in 1. Seven patients harbored anterior circulation aneurysms. Two additional patients harbored nonaneurysmal lesions., Results: Perioperatively, 14 patients (14%) died. Five patients (5%) were lost to late follow-up. At a mean long-term follow-up of 9.7 years, 65 patients (63%) had the same or a better status after surgical intervention, 10 (10%) were worse, and 9 (9%) had died. There were 19 cases (18%) of permanent or severe complications. The combined rate of permanent treatment-related morbidity and mortality was 32%. The mean late follow-up Glasgow Outcome Scale score was 4, and the annual hemorrhage rate after microsurgical clipping during cardiac standstill was 0.5%/year. Ninety-two percent of patients required no further treatment of their aneurysm at the long-term follow-up., Conclusions: Cardiac standstill remains an important treatment option for a small subset of complex and giant posterior circulation aneurysms. Compared with the natural history of the disease, the risk associated with this procedure is acceptable.

Object: Hypothalamic hamartomas (HHs) are devastating lesions causing refractory epilepsy, rage attacks, social ineptitude, and precocious puberty. Microsurgical and/or endoscopic resection offers an excellent risk/benefit profile for cure or improvement of epilepsy., Methods: The authors reviewed a prospective database maintained during the first 7 years of the Barrow Hypothalamic Hamartoma program. They describe and illustrate their surgical methods, and they review data from several previous publications regarding surgical outcome., Results: To date, the authors have performed surgery in 165 patients for symptomatic HHs. Patients underwent an endoscopic, transcallosal, or skull base approach, or multiple approaches. Twenty-six patients (15.8%) required more than 1 treatment for their HH., Conclusions: Microsurgical and endoscopic resection of symptomatic HHs are technically demanding but can be performed safely with excellent results and an acceptable risk profile. Meticulous attention to the subtleties of surgical management helps optimize outcomes.

Object: In this paper, the authors' goal was to describe the occurrence of alternating hypernatremia and hyponatremia in pediatric patients who underwent resection of hypothalamic hamartomas (HHs) for epilepsy. Hypernatremia in patients after pituitary or hypothalamic surgery can be caused by diabetes insipidus (DI), whereas hyponatremia can occur due to a syndrome of inappropriate antidiuretic hormone, cerebral salt wasting, or excessive administration of desmopressin (DDAVP). The triphasic response after surgery in the pituitary region can also explain variations in sodium parameters in such cases., Methods: One hundred fifty-three patients with HH who underwent surgery were enrolled in a prospective study to monitor outcomes. Of these, 4 patients (2.6%) were noted to experience dramatic alterations in serum sodium values. The medical records of these patients were identified and evaluated., Results: Patients' ages at surgery ranged from 1.2 to 6.0 years. All patients were girls. Two patients had Delalande Type IV lesions (of 16 total Type IV lesions surgically treated) and 2 had Type III lesions (of 39 total Type III lesions). All patients had a history of gelastic seizures refractory to medication. Seizure frequency ranged from 3 to 300 per day. After surgery, all patients experienced hypernatremia and hyponatremia. The largest fluctuation in serum sodium concentration during hospitalization in a single patient was 53 mEq/L (range 123-176 mEq/L). The mean absolute difference in maximum and minimum sodium values was 38.2 mEq/L. All patients exhibited an initial period of immediate DI (independent of treatment) after surgery followed by a period of hyponatremia (independent of treatment), with a minimum value occurring between postoperative Days 5 and 8. All patients then returned to a hypernatremic state of DI, and 3 patients still require DDAVP for DI management. A second occurrence of hyponatremia lasting several days without DDAVP administration occurred in 2 patients during their hospitalization between periods of hypernatremia. One patient stabilized in the normal range of sodium values prior to discharge from rehabilitation without the need for further intervention. At last follow-up, 3 patients are seizure-free., Conclusions: Severe instability of sodium homeostasis with hypernatremia and hyponatremia is seen in up to 2.6% of children undergoing open resection of HH. This risk appears to be related to HH type, with a higher risk for Types III (2 [5.1%] of 39) and IV (2 [12.5%] of 16) lesions. Here, the authors describe alternating episodes of hypernatremia and hyponatremia in the postoperative period following HH surgery. Management of this entity requires careful serial assessment of volume status and urine concentration and will often require alternating salt replacement therapy with DDAVP administration.

Purpose: This study aims to examine the outcomes of ten patients after orbitozygomatic (OZ) pterional surgery in cases of refractory epilepsy caused by hypothalamic hamartomas (HH)., Methods: Ten patients with HH and treatment-resistant epilepsy (mean age 18.3 years, range 0.7 to 42.7) underwent HH resection with an OZ approach (n = 8) or an OZ approach combined with a transventricular endoscopic approach (n = 2). Follow-up for the patients ranged from 0.5 to 6.2 years (mean 3.1). Outcomes were prospectively monitored with the use of a proprietary database., Results: Four patients (40%) are seizure-free, and four (40%) have had greater than 50% reduction in seizures. One patient had no significant change in seizure frequency, and one patient died unexpectedly 2.8 years after surgery. Six patients had total or near-total HH resection (98-100% of HH lesion volume). Of these, four of six (66%) were seizure-free, and two had at least greater than 50% reduction in seizures. Residual complications include diabetes insipidus (n = 1), poikilothermia (n = 1), visual field deficit (n = 1), and hemiparesis (n = 1). Eight families (80%) reported improved quality of life., Conclusions: Patients with treatment-resistant epilepsy and tumors with an inferior or horizontal plane of attachment to the hypothalamus should continue to be approached from below. Those with both intrahypothalamic and parahypothalamic components may require approaches from above and below, either simultaneously or staged. For appropriately selected patients, the success of controlling seizures with an OZ is comparable to results utilizing transcallosal or transventricular approaches. The likelihood of controlling seizures appears to correlate with extent of resection.

Object: The authors present outcomes obtained in patients who underwent Gamma Knife surgery (GKS) at 1 institution as part of a multimodal treatment of refractory epilepsy caused by hypothalamic hamartomas (HHs)., Methods: Between 2003 and 2010, 19 patients with HH underwent GKS. Eight patients had follow-up for less than 1 year, and 1 patient was lost to follow-up. The 10 remaining patients (mean age 15.1 years, range 5.7-29.3 years) had a mean follow-up of 43 months (range 18-81 months) and are the focus of this report. Five patients had undergone a total of 6 prior surgeries: 1 transcallosal resection of the HH, 2 endoscopic transventricular resections of the HH, 2 temporal lobectomies, and 1 arachnoid cyst evacuation. In an institutional review board-approved study, postoperative complications and long-term outcome measures were monitored prospectively with the use of a proprietary database. Seven patients harbored Delalande Type II lesions; the remainder harbored Type III or IV lesions. Seizure frequency ranged from 1-2 monthly to as many as 100 gelastic seizures daily. The mean lesion volume was 695 mm(3) (range 169-3000 mm(3), median 265 mm(3)). The mean/median dose directed to the 50% isodose line was 18 Gy (range 16-20 Gy). The mean maximum point dose to the optic chiasm was 7.5 Gy (range 5-10 Gy). Three patients underwent additional resection 14.5, 21, and 32 months after GKS., Results: Of the 10 patients included in this study, 6 are seizure free (2 after they underwent additional surgery), 1 has a 50%-90% reduction in seizure frequency, 2 have a 50% reduction in seizure frequency, and 1 has observed no change in seizure frequency. Overall quality of life, based on data obtained from follow-up telephone conversations and/or surveys, improved in 9 patients and was due to improvements in seizure control (9 patients), short-term memory loss (3 patients), and behavioral symptoms (5 patients); in 1 patient, quality of life remains minimally affected. Incidences of morbidity were all temporary and included poikilothermia (1 patient), increased depression (1 patient), weight gain/increased appetite (2 patients), and anxiety (1 patient) after GKS., Conclusions: Of the approximately 150 patients at Barrow Neurological Institute who have undergone treatment for HH, the authors have reserved GKS for treatment of small HHs located distal from radiosensitive structures in patients with high cognitive function and a stable clinical picture, which allows time for the effects of radiosurgery to occur without further deterioration. The lack of significant morbidity and the clinical outcomes achieved in this study demonstrated a low risk of GKS for HH with results comparable to those of previous series.

Object: Many patients undergoing carotid endarterectomy (CEA) regularly take clopidogrel, a permanent platelet inhibitor. The authors sought to determine whether taking clopidogrel in the period before CEA leads to more bleeding or other complications., Methods: The authors performed a retrospective, institutional review board–approved review of 182 consecutive patients who underwent CEA. Clinical, radiographic, and surgical data were gleaned from hospital and clinic records. Analysis was based on the presence or absence of clopidogrel in patients undergoing CEA and was performed twice by considering clopidogrel use within 8 days and within 5 days of surgery to define the groups., Results: Taking clopidogrel within 8 days before surgery resulted in no statistical increase in any measure of morbidity or death. Taking clopidogrel within 5 days was associated with a small but significant increase in operative blood loss and conservatively managed postoperative neck swelling. No measure of permanent morbidity or death was increased in either clopidogrel group., Conclusions: Findings in this study support the safety of preoperative clopidogrel in patients undergoing CEA.

Background: Rathke cleft cyst can enlarge and become symptomatic., Objective: To review the clinical data and results of all patients treated by the senior author for a Rathke cleft cyst., Methods: A prospectively maintained surgical database, supplemented with updates from telephone conversations, of all patients presenting to the Barrow Neurological Institute from 1992 to the present was reviewed., Results: Seventy-three patients (17 males, 56 females; mean age, 40 years; range, 5-80 years) underwent 77 resections. The mean length of follow-up was 27 months (range, 0-129 months). Presenting symptoms included headache (75%), followed by endocrinopathy (49%), and visual symptoms (39%). Preoperative chiasmopathy resolved in 75% and improved in 21% of the patients. Patients' preoperative endocrinopathy resolved at various rates, depending on the specific axis (29%-100%). Endocrinopathies were more likely to resolve in females than males. New postoperative endocrinopathies also occurred (0-8%). Headache resolved (68%) or improved (21%) in most patients. No patient had worsened headaches. Eight patients had a recurrence, 4 of whom underwent reoperation. The presence of squamous metaplasia was the only predictor of recurrence., Conclusion: Surgical fenestration and/or resection of Rathke cleft cyst via the transsphenoidal approach are a rational choice for surgical management of these lesions when symptomatic. In most cases, visual symptoms and headache can be expected to improve. New persistent endocrine deficits can be expected in a small percentage of patients, but preexisting endocrinopathies resolve in many patients.

Background: Hyperhidrosis (HH) profoundly affects a patient's well-being., Objective: We report indications and outcomes of 322 patients treated for HH via thoracoscopic sympathectomy or sympathotomy at the Barrow Neurological Institute., Methods: A prospectively maintained database of all patients who underwent sympathectomy or sympathotomy between 1996 and 2008 was examined. Additional follow-up was obtained in clinic, by phone, or by written questionnaire., Results: A total of 322 patients (218 female patients) had thoracoscopic treatment (mean age 27.6 years; range, 10-60 years). Mean follow-up was 8 months. Presentations included HH of the palms (43 patients, 13.4%), axillae (13 patients, 4.0%), craniofacial region (4 patients, 1.2%), or some combination (262 patients, 81.4%). Sympathectomy and sympathotomy were equally effective in relieving HH. Palmar HH resolved in 99.7% of patients. Axillary or craniofacial HH resolved or improved in 89.1% and 100% of cases, respectively. Hospital stay averaged 0.5 days. Ablating the sympathetic chain at T5 increased the incidence of severe compensatory sweating (P = .0078). Sympathectomy was associated with a significantly higher incidence of Horner's syndrome compared with sympathotomy (5% vs 0.9%, P = .0319). Patients reported satisfaction and willingness to undergo the procedure again in 98.1% of cases., Conclusion: Thoracoscopic sympathectomy is effective and safe treatment for severe palmar, axillary, and craniofacial HH. Ablating the T5 ganglion tends to increase the severity of compensatory sweating. Sympathectomy led to a higher incidence of ipsilateral Horner's syndrome compared with sympathotomy.

Object: Palmar, axillary, and plantar hyperhidrosis is often socially, emotionally, and physically disabling for adolescents. The authors report surgical outcomes in all adolescents treated for palmar hyperhidrosis via bilateral thoracoscopic sympathectomy at the Barrow Neurological Institute by the senior author., Methods: A prospectively maintained database of all adolescent patients undergoing bilateral thoracoscopic sympathectomy between 1998 and 2006 (inclusive) was reviewed. Additional follow-up was obtained as needed in clinic or by phone or written questionnaire., Results: Fifty-four patients (40 females) undergoing bilateral procedures were identified. Their mean age was 15.4 years (range 10-17 years). Average follow-up was 42 weeks (range 0.2-143 weeks). Hyperhidrosis involved the palms alone in 10 patients; the palms and axilla in 6 patients; the palms and plantar surfaces in 17 patients; and the palms, axilla, and plantar surfaces in 21 patients. Palmar hyperhidrosis resolved completely in 98.1% of the patients. Resolution or improvement of symptoms was seen in 96.3% of patients with axillary and 71.1% of those with plantar hyperhidrosis. Hospital stay averaged 0.37 days with 68.5% of patients discharged the day of surgery. One patient experienced brief intraoperative asystole that resolved with medications and had no long-term sequelae. Otherwise, no serious intraoperative complications occurred. No patient required chest tube drainage. The percentage of patients who reported satisfaction and willingness to undergo the procedure again was 98.1%., Conclusions: Biportal, bilateral thoracoscopic sympathectomy is an effective and low-morbidity treatment for severe palmar, axillary, and plantar hyperhidrosis.

Introduction: The CO2 laser has a long history in both experimental and clinical neurosurgery. However, its use over the past decade has been limited by its cumbersome design and bulky set-up of the micromanipulator. These limitations are amplified when it is used with the operating microscope. These restrictions are addressed by the Omniguide fiber, which delivers the beam through flexible hollow-core photonic bandgap mirror fibers and allows the laser to be wielded like any other surgical instrument., Methods: The attending neurosurgeon prospectively assessed the usefulness of the laser in its first 45 consecutive uses at our institution based on a scale of 1 to 5., Results: The series included 11 cavernous malformations, 14 meningiomas, 7 ependymomas, 3 metastases, 3 astrocytomas, and 7 miscellaneous lesions. The laser was set up 91 times and used in 45 cases. The Omniguide fiber failed 5 times. No adverse events involving patients or staff were associated with laser use. The mean utility score was 3.7 +/- 0.8 (range, 2-5). The laser was most helpful in debulking fibrous lesions too tough for ultrasonic aspiration and lesions adherent to delicate neurovascular structures. The laser was not helpful with highly vascular tumors., Conclusion: In our early experience, the Omniguide laser was very helpful in selected cases in resecting specific types of lesions without complications; we have added the device to our neurosurgical armamentarium.

Objective: We measured the variability in the size of the anterior tubercle of C1 and the optimal depth and angle of placement of C1 lateral mass screws using axial and sagittal reconstructed computed tomographic scans to determine the utility of these parameters for preoperative planning and intraoperative guidance., Methods: One hundred consecutive cervical spine computed tomographic scans were reviewed (mean patient age, 44.6 years; age range, 7-96 years). The size of the anterior tubercle of C1, bilateral depths of optimal screw placement in the axial and sagittal planes, and optimal angles of placement in the axial and sagittal planes were measured in a standardized manner using the measuring tool included in our radiology server software. These measurements were correlated with age and sex., Results: The mean depth of the C1 tubercle was 6.9 mm (range, 2.7-11.2 mm; standard deviation, 1.7 mm). The depth of the C1 tubercle tended to increase with age, but the relationship was not significant. The optimal screw depth in the sagittal plane was significantly greater than in the axial plane (right 2.09 versus 1.93 cm; left 2.07 versus 1.91 cm). The depth of the right lateral mass increased significantly with age. No other relationships reached significance., Conclusion: The depth of the anterior tubercle of C1 varies considerably and should be studied carefully before using lateral fluoroscopy of this structure to guide depth of C1 lateral mass screw placement. Optimal angles and depths of placement of C1 lateral mass screws vary widely and should be examined preoperatively to plan appropriate depth and trajectory.

Objective: We describe a novel technique used to repair an unanticipated tear of the internal carotid artery (ICA) requiring anterior cerebral artery (ACA) amputation to allow primary repair of the arteriotomy., Clinical Presentation: A 59-year-old woman underwent an orbitozygomatic craniotomy to treat a large, suprasellar, thyroid-stimulating hormone-secreting adenoma. During resection, an incidental ICA tear occurred opposite the exit of the middle cerebral artery., Technique: After an ICA tear on the wall opposite the middle cerebral artery occurred, clips were placed on the ICA, middle cerebral artery, and ACA. Primary closure was not feasible without critically stenosing the ICA. The ipsilateral ACA was clipped and amputated just distal to its origin. The relaxation afforded by amputating the ACA allowed primary suture repair of the arteriotomy. A clip was placed on the proximal ACA stump. The distal ACA stump revealed good backflow and was also clipped., Conclusion: When an arteriotomy of a large intracranial artery cannot be repaired primarily, creative alternatives must be considered. Amputation of a branch artery with sufficient collateral flow is a method to afford adequate relaxation for primary repair of an arteriotomy. This novel method should be considered in the armamentarium of neurosurgeons to minimize the impact of potentially disastrous vascular complications.

Neuroleptic malignant syndrome (NMS) is a potentially life-threatening entity characterized by hyperthermia, autonomic deregulation, decreased mental status, increased muscle tone, and, frequently, by renal failure due to rhabdomyolysis. Classically, it follows administration of antipsychotic medication. The authors report on 4 patients (2 children and 2 adults) in whom NMS was diagnosed after a CNS insult. No patient was receiving antipsychotic medication. The patients' hospital and clinic charts, radiographic data, and follow-up telephone conversations were reviewed retrospectively. All 4 patients met diagnostic criteria for NMS. Three patients presented with shunt failure, and 1 patient had undergone a functional hemispherectomy 2 days earlier. One patient with shunt failure received the diagnosis retrospectively. An endoscopic third ventriculostomy alleviated his shunt failure and he remains free of NMS. The other 2 patients underwent treatment for shunt failure, but NMS remained. These 2 patients and the one who had undergone hemispherectomy underwent a trial of intrathecal baclofen, and the NMS resolved. Subsequently, an intrathecal baclofen infusion device was placed in all 3 patients, and the NMS resolved. The 2 patients in shunt failure had a lumbar intrathecal baclofen infusion device. The patient who had undergone hemispherectomy had an intracranial baclofen catheter. Neuroleptic malignant syndrome is a rare, life-threatening disorder that can occur without the administration of neuroleptic medications. Alleviation of any CNS insult is the first order of treatment. Some patients with persistent symptoms of NMS may benefit from intrathecal delivery of baclofen.

Objective: Microscope-integrated indocyanine green (ICG) fluorescence angiography is a novel technique in vascular neurosurgery with potential utility in treating arteriovenous malformations (AVMs)., Methods: We analyzed the application of intraoperative ICG in 10 consecutive AVM surgeries for which surgical video was available. The ability to distinguish AVM vessels (draining veins, feeding and nidal arteries) from each other and from normal vessel was evaluated, and ICG angiographic findings were correlated with intra- and postoperative findings on digital subtraction angiography (DSA)., Results: ICG angiography was found to be useful by the surgeon in 9 of 10 patients. In 8 patients, it helped to distinguish AVM vessels. In 3 of 4 patients undergoing a postresection injection, it demonstrated that there was no residual arteriovenous shunting. In 1 patient, it helped to identify a small AVM nidus that was otherwise inapparent within a hematoma. Intraoperative DSA showed residual AVM in 2 of 10 patients requiring further resection of AVM not visualized during surgery., Conclusion: Microscope-integrated ICG angiography is a useful tool in AVM surgery. It can be used to distinguish AVM vessels from normal vessels and arteries from veins based on the timing of fluorescence with the dye. Our experience suggests that it is less useful with deep-seated lesions or when AVM vessels are not on the surface. ICG angiography complements rather than replaces DSA.

Isolated brainstem abscess, specifically, medullary abscess, is rare and often fatal. Diagnosis requires appropriate imaging and a high degree of clinical suspicion. Good outcomes are possible. A 69-year-old woman presented with an isolated medulla oblongata abscess that manifested as a syndrome of rapidly progressive multiple cranial nerve palsies and decreased level of consciousness. Microneurosurgical incision and drainage of the medullary abscess were performed. Maximal therapy of antibiotics, intensive care management, and extended rehabilitation was delivered. A prompt diagnosis of medullary abscess, with immediate microneurosurgical intervention and maximal medical therapy, may result in a good outcome.

Objective: Surgical biopsy of isolated infundibular lesions is indicated in patients who are symptomatic or whose imaging suggests a treatable lesion. Early therapy can prevent irreversible neurological or endocrinological damage and, potentially, metastasis. These considerations justify the small risk associated with surgery., Clinical Presentation: A 5-year-old boy presented with diabetes insipidus and an enhancing lesion of the pituitary stalk without evidence of extracranial disease., Intervention: The lesion was biopsied via an endoscopic intraventricular approach without complications. Pathological examination revealed Langerhans cell histiocytosis., Conclusion: Endoscopic intraventricular biopsy can be considered as a less invasive alternative to craniotomy in patients with infundibular lesions protruding superiorly into the third ventricle.