Very delayed CSF leak in patients after craniotomy for resection of skull base tumors.

OBJECTIVE: Cerebrospinal fluid (CSF) leak is a potentially dangerous neurosurgical complication. Delayed CSF leak has already been described after trauma, radiation therapy and endonasal transsphenoidal surgery for Sella turcica pathologies. Still, very few reported cases describe delayed CSF leak after craniotomy for tumors. We present our experience with patients showing delayed CSF leak after skull base tumor resection. METHODS: Data for all tumors resected from the skull base region from January 2004 to December 2018 was retrieved from the surgeon's prospective database and supplemented with a retrospective file review. Patients who presented CSF leak within the first 12 months after surgery and those with a history of trauma or radiation-based treatment to the skull base region were excluded from the study. Epidemiology, clinical presentation, previous surgical approach, pathology, interval between craniotomy and CSF leak and proposed treatment were analyzed. RESULTS: Overall, more than two thousand patients underwent surgery for resection of skull base tumors during the study period. Six patients (two male, four female; mean age 57.5 years, range 30-80) presented with delayed CSF leak, including five (83%) who presented with bacterial meningitis. After skull base tumor resection, CSF leak developed in a mean of 72 months (range 12-132). Three patients underwent retrosigmoid craniotomy, two for resection of cerebellopontine angle epidermoid cyst and one for resection of a petro tentorial meningioma; one had trans petrosal retrolabyrinthine craniotomy for resection of a petroclival epidermoid cyst; one had far lateral craniotomy for resection of a foramen magnum meningioma; and one had pterional craniotomy for resection of a cavernous sinus meningioma. All patients underwent surgical re-exploration and repair. CSF leak was managed with mastoid obliteration in five patients and skull base reconstruction with fat graft in one. CONCLUSION: Recognition of very delayed CSF leak as a potential complication after resection of skull base tumors may be useful tool in long-term patient management. In our experience, these patients usually present with bacterial meningitis. Surgical options should be considered as a definitive treatment.

Cavernous Sinus Epidermoid Cyst Removal through a No-Keyhole Pterional Craniotomy: Operative Video and Technical Nuances.

Intracranial epidermoid cysts are considered benign tumors with good general prognosis. However, their radical removal may be associated with certain morbidity, especially when the capsule is attached to neurovascular structures. Epidermoid cysts located in the cavernous sinus are very rare. We present an operative video of a 22-year-old female patient, who suffered a right-sided headache for 5 years. The video demonstrates main steps and surgical nuances of resection of a right interdural cavernous sinus epidermoid cyst, measuring 22 × 19 × 21 mm (4.3 cc) ( Fig. 1A ). On initial physical examination, the patient had a right partial third nerve palsy (mild ptosis with minimal diplopia), without any other cranial nerve deficit. A right no-keyhole pterional craniotomy was performed, followed by extradural anterior clinoidectomy and peeling of the outer dural layer of the lateral wall of the cavernous sinus. The dura matter was also detached from the distal carotid dural ring, which was exposed by the clinoidectomy ( Fig. 2A ). This maneuver provided excellent exposure of the interdural epidermoid cyst, which severely compressed the oculomotor nerve against the posterior petroclinoid dural fold ( Fig. 2B ). Gross total resection of the epidermoid cyst was achieved ( Fig. 1B and C ). The patient developed a transient worsening of the third nerve palsy, which recovered completely 3 months after the surgery. Postoperative magnetic resonance imaging revealed no signs of residual tumor. The link to the video can be found at: https://youtu.be/pobhYb5ZNig .

Solid vs. cystic predominance in posterior fossa hemangioblastomas: implications for cerebrovascular risks and patient outcome.

BACKGROUND: Hemangioblastomas (HGBs) are highly vascular benign tumors, commonly located in the posterior fossa, and 80% of them are sporadic. Patients usually present with features of raised intracranial pressure and cerebellar symptoms. HGB can be classified as either mostly cystic or solids. Although the solid component is highly vascularized, aneurysm or hemorrhagic presentation is rarely described, having catastrophic results. METHODS: We identified 32 consecutive patients with posterior fossa HBG who underwent surgery from 2008 through 2020 at our medical center. Tumors were classified as predominantly cystic or solid according to radiological features. Resection was defined as gross total (GTR) or subtotal (STR). RESULTS: During the study period, 32 posterior fossa HGBs were resected. There were 26 cerebellar lesions and 4 medullar lesions, and in 2 patients, both structures were affected. Predominant cystic tumors were seen in 15 patients and solids in 17. Preoperative digital subtraction angiography (DSA) was performed in 8 patients with solid tumors, and 4 showed tumor-related aneurysms. Embolization of the tumors was performed in 6 patients, including the four tumor-related aneurysms. GTR was achieved in 29 tumors (91%), and subtotal resection in 3 (9%). Three patients had postoperative lower cranial nerve palsy. Functional status was stable in 5 patients (16%), improved in 24 (75%), and 3 patients (9%) deteriorated. One patient died 2 months after the surgery. Two tumors recurred and underwent a second surgery achieving GTR. The mean follow-up was 42.7 months (SD ± 51.0 months). CONCLUSIONS: Predominant cystic HGB is usually easily treated as the surgery is straightforward. Those with a solid predominance present a more complex challenge sharing features similar to arteriovenous malformations. Given the important vascular association of solid predominance HGB with these added risk factors, the preoperative assessment should include DSA, as in arteriovenous malformations, and endovascular intervention should be considered before surgery.

Fusion of Preoperative and Postoperative Imaging May Predict the Diagnostic Yield of Stereotactic Needle Brain Biopsies.

BACKGROUND: Stereotactic needle brain biopsy is a commonly used neurosurgical procedure. However, up to 15% of biopsies result in undiagnostic pathology reports. Repeat biopsy or continued management without a diagnosis are often considered after undiagnostic biopsies. There have been no reports about the role of postoperative imaging in predicting the diagnostic yield of stereotactic biopsies. METHODS: We retrospectively assessed all stereotactic biopsies performed over an 11-year period. We performed fusion of immediate postoperative computed tomography (CT) with preoperative MRI, to document whether the air bubble in the postoperative CT was located within the targeted lesion. We then evaluated the association of this fusion-based accuracy assessment with the diagnostic yield of the biopsy. RESULTS: Fewer than 5% of biopsies did not have an air bubble on postoperative CT. A total of 226 biopsies were performed for 219 patients. In our sample, 213 of 226 biopsies were accurate (94.2% accuracy rate), and 203 of 226 biopsies gave a definitive diagnosis (89.8% diagnostic rate). In those cases where the fusion was accurate, the diagnostic rate was 93.9%. When the fusion was inaccurate, the diagnostic rate was only 23.1% (odds ratio 51.5, 95% confidence interval 12.6-210.44, P < 0.001). Of all patient, imaging, surgical, and admission parameters, the only parameter that correlated with diagnostic outcome of the biopsy was the fusion construct accuracy. CONCLUSIONS: Fusion of immediate postoperative CT with preoperative imaging is predictive of the diagnostic rate. In cases where the pathology report following a biopsy is not diagnostic, this fusion may be useful in making decisions regarding repeat biopsy or considering other diagnostic options.

Superficial Temporal Artery-Middle Cerebral Artery Microvascular Bypass: Its Role in Treatment of Patients with Moyamoya Disease, Cerebral Aneurysms, and Vascular Occlusive Disease.

BACKGROUND: Superficial temporal artery-middle cerebral artery microvascular bypass (STA-MCA MVB) is an important strategy for the management of selected patients OBJECTIVES: To present our 19-year experience with STA-MCA MVB METHODS: Data for consecutive patients who underwent STA-MCA MVB from 2000­2019 due to moyamoya/moyamoya-like disease, complex intracranial aneurysms, or intractable brain ischemia due to internal carotid artery or MCA occlusive disease with repeated ischemic events were retrospectively analyzed under a waiver of informed consent. Key surgical steps and the important role of neuroendovascular interventions are presented. Surgical results and late outcomes were analyzed RESULTS: The study included 32 patients (17 women [53%], 15 men [47%]), mean age 42.94 years (range 16­66). The patients underwent 37 STA-MCA MVB procedures during the study period: 22 with moyamoya/moyamoya-like disease (69%) underwent 27 surgeries (five bilateral); 7 patients with complex aneurysms (22%) and 3 patients with vascular occlusive disease (9%) underwent unilateral bypass. Five of seven aneurysms were treated with coiling or flow-diverter stent implant prior to bypass surgery; two were clipped during the bypass procedure. There were no surgical complications, no perioperative mortality, and no death from complications related to neurovascular disease at late follow-up. Transient neurological deficits following 7/37 surgeries (19%) resolved with no permanent neurologic sequelae. Transient ischemic attacks occurred only in the immediate postoperative period in four patients (11%) CONCLUSIONS: In specific cases, STA-MCA MVB is a feasible and clinically effective procedure. It is important to preserve this technique in the surgical armamentarium

Flow-diverter stents in the early management of acutely ruptured brain aneurysms: effective rebleeding protection with low thromboembolic complications.

OBJECTIVE: Flow-diverter stents (FDSs) are not generally used for the management of acutely ruptured aneurysms with associated subarachnoid hemorrhage (SAH). Herein, the authors present their experience with FDSs in this scenario, focusing on the antiplatelet regimen, perioperative management, and outcome. METHODS: The authors retrospectively reviewed their institutional database for the treatment and outcomes of all patients with acutely ruptured aneurysms and associated SAH from July 2010 to September 2018 who had received an FDS implant as stand-alone treatment within 4 days after diagnosis. The protocol with the use of flow diversion in these patients includes a low threshold for placement of external ventricular drains before stenting, followed by the administration of aspirin and clopidogrel with platelet testing before stent implantation. With this approach, the risk of hemorrhage and stent-related thrombus formation is limited. Demographic, clinical, technical, and imaging data were analyzed. RESULTS: Overall, 76 patients (61% females, mean age 42.8 ± 11.3 years) met the inclusion criteria. FDS implantation was performed a median of 2 days after diagnosis. On average, 1.05 devices were used per procedure. There was no procedural mortality directly attributed to the endovascular intervention. Procedural device-related clinical complications were recorded in a total of 6 cases (7.9%) and resulted in permanent neurological morbidity in 2 cases (2.6%). There was complete immediate aneurysm occlusion in 11 patients (14.5%), and persistent aneurysm filling was seen in 65 patients (85.5%). Despite this, no patient presented with rebleeding from the target aneurysm. There was an excellent clinical outcome in 62 patients (81.6%), who had a 90-day modified Rankin Scale score of 0-2. Among the 71 survivors, total or near-total occlusion was observed in 64/67 patients (95.5%) with a 3- to 6-month angiographic follow-up and in all cases evaluated at 12 months. Five patients (6.6%) died during follow-up for reasons unrelated to the procedure or new hemorrhage. CONCLUSIONS: Flow diversion is an effective therapeutic strategy for the management of select acutely ruptured aneurysms. Despite low rates of immediate aneurysm occlusion after FDS implantation, the device exerts an important protective effect. The authors' experience confirmed no aneurysm rerupture, high rates of delayed complete occlusion, and complication rates that compare favorably with the rates obtained using other techniques.

[18F]-FDHT PET/CT as a tool for imaging androgen receptor expression in high-grade glioma.

BACKGROUND: G lioblastoma (GBM) is associated with poor overall survival. Recently, we showed that androgen receptor (AR) protein is overexpressed in 56% of GBM specimens and AR antagonists induced dose-dependent death in several GBM cell lines and significantly reduced tumor growth and prolonged the lifespan of mice implanted with human GBM. 16ß-18F-fluoro-5α-dihydrotestosterone ([18F]-FDHT) is a positron emission tomography (PET) tracer used to detect AR expression in prostate and breast cancers. This study was aimed at exploring the ability of [18F]-FDHT-PET to detect AR expression in high-grade gliomas. METHODS: Twelve patients with suspected high-grade glioma underwent a regular workup and additional dynamic and static [18F]-FDHT-PET/CT. Visual and quantitative analyses of [18 F]-FDHT kinetics in the tumor and normal brain were performed. Mean and maximum (max) standardized uptake values (SUVs) were determined in selected volumes of interest. The patients had surgery or biopsy after PET/CT. AR protein was analyzed in the tumor samples by western blot. Fold change in AR expression was calculated by densitometry analysis. Correlation between imaging and AR protein samples was determined. RESULTS: In six of the 12 patients, [18 F]-FDHT uptake was significantly higher in the tumor than in the normal brain. These patients also had increased AR protein expression within the tumor. Pearson correlation coefficient analysis for the tumor-to-control normal brain uptake ratio in terms of SUVmean versus AR protein expression was positive and significant (R = 0.84; P = .002). CONCLUSION: [18 F]-FDHT-PET/CT could identify increased AR expression in high-grade glioma.

Vestibular schwannoma manifesting with hemifacial spasm in a young woman: clinical considerations and tumor removal with hearing preservation. 2-Dimensional operative video.

Hemifacial spasm (HFS) is a rare presentation of vestibular schwannoma. The authors present their experience with a 27-year-old woman who presented with normal hearing and HFS, which was the single neurological manifestation of an 18-mm vestibular schwannoma. In this challenging situation, the treatment goals were maximal tumor removal with preservation of hearing and facial nerve function and cure of the HFS. The authors achieved these goals, performing complete tumor removal via a retrosigmoid approach, assisted with neurophysiological monitoring and a 45°-angle QEVO endoscope. In the video, they explain the clinical, radiological, and surgical considerations and demonstrate the surgical technique. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2099.

Progressive facial numbness in a patient with multiple enhancing dural based tumours: Question.

Sarcoidosis is uncommon multiple organ granulomatous disease of unknown etiology. Neurosarcoidosis occurs in about 5% of cases and most frequently follows systemic disease. We present a case of 52 -years -old woman with a progressive hemifacial paresthesia and multiple enhancing dural based lesions. Resection of the right frontal mass allowed for the diagnosis to be made. The patient had no other features of sarcoidosis. Therefore, the diagnosis of neurosarcoidosis, especially when unaccompanied by systemic features can be challenging but should be considered in the differential diagnosis of multiple enhancing dural based tumours.

Progressive facial numbness in a patient with multiple enhancing dural based tumours: Answer.

Sarcoidosis is uncommon multiple organ granulomatous disease of unknown etiology. Neurosarcoidosis occurs in about 5% of cases and most frequently follows systemic disease. We present a case of 52-years-old woman with a progressive hemifacial paresthesia and multiple enhancing dural based lesions. Resection of the right frontal mass allowed for the diagnosis to be made. The patient had no other features of sarcoidosis. Therefore, the diagnosis of neurosarcoidosis, especially when unaccompanied by systemic features can be challenging but should be considered in the differential diagnosis of multiple enhancing dural based tumours.

Spontaneous symptomatic orbital meningoencephalocele in an adult patient. Case report and review of the literature.

Symptomatic spontaneous meningoencephalocele (MEC) is a very rare entity in adults and there have been no reported cases of spontaneous MEC through the orbital roof in an adult. We report a 41-year-old woman who presented with a left eyelid swelling for several weeks without any history of trauma. Brain magnetic resonance imaging (MRI) showed a MEC through the orbital roof causing a significant blepharocele in this young patient. Supraorbital craniotomy was performed to repair the bone defect. The symptoms resolved immediately after surgery. Even though blepharocele is a rare manifestation of spontaneous orbital MEC it should be considered in the differential diagnosis for appropriate surgical management.

The oblique occipital sinus - implications in posterior fossa approaches.

The retrosigmoid craniotomy is the standard approach to resect pathologies in the cerebellopontine angle (CPA). Following the craniotomy, the dura mater is opened in the inferolateral direction and the basal cistern arachnoid is dissected in order to release pressure by the outflow of cerebrospinal fluid (CSF) from the foramen magnum, so that the CPA compartment can be approached with minimal retraction of the cerebellum. We report two patients, both with vestibular schwannoma, in whom preoperative magnetic resonance imaging (MRI) revealed unusual large oblique occipital sinus (OOS) draining laterally into the sigmoid sinus - jugular bulb junction. The sinuses were preserved intact while dura mater was opened for CSF release. Careful preoperative imaging is essential prior to posterior fossa lesions approaches in order to evaluate the persistency of an OOS, especially in a retrosigmoid approach. Inadvertent OOS damage might result in, not only significant bleeding during dural opening, but also air embolism or venous hypertension, if the contralateral sigmoid sinus is small or absent.

Repeated spontaneous intra-tumoural and subarachnoid haemorrhage in an anticoagulated patient with a previously-irradiated vestibular Schwannoma: Case report.

Subarachnoid hemorrhage caused by vestibular schwannomas (VS) is rare with no clear pathological mechanism supported in the existing literature. However, anticoagulation treatment as well as previous radiation therapy appear to be a crucial risk factor for subarachnoid haemorrhage from a VS. We report an unusual case of both intratumoural and subarachnoid haemorrhage in a patient with a VS on anticoagulation treatment previously treated with stereotactic radiosurgery. We emphasize the need for caution when considering the use of radiation therapy for treatment of VS in patients on chronic anticoagulation therapy.

Tractography-Guided Deep Brain Stimulation of the Anteromedial Globus Pallidus Internus for Refractory Obsessive-Compulsive Disorder: Case Report.

BACKGROUND AND IMPORTANCE: Obsessive-compulsive disorder (OCD) is a disabling psychiatric disorder, mainly treated with psychotherapy and pharmacotherapy. Surgical intervention may be appropriate for patients with treatment-refractory OCD. Deep brain stimulation (DBS) is an alternative for previously common ablative surgical procedures. Tractography has been proposed as a method for individualizing DBS treatment and may have the potential to improve efficacy. CLINICAL PRESENTATION: We present a patient with treatment-refractory OCD previously treated with bilateral leucotomies, who underwent DBS surgery with targeting informed by tractography. Preoperative tractography to identify suitable DBS targets was undertaken. Structural images were also utilized for standard stereotactic surgical planning. The anteromedial globus pallidus internus (amGPi) was chosen as the target bilaterally after consideration of white matter projections to frontal cortical regions and neurosurgical approach. Bilateral amGPi DBS surgery was undertaken without adverse events. At 16-mo follow-up, there was a 48.5% reduction in OCD symptom severity as measured by the Yale-Brown Obsessive Compulsive Scale. CONCLUSION: The amGPi can be a successful DBS target for OCD. This is the first known case to report on DBS surgery postleucotomies for OCD and highlights the utility of tractography for surgical planning in OCD.

The infratranstentorial subtemporal approach (ITSTA): a valuable skull base approach to deep-seated non-skull base pathology.

BACKGROUND: Surgical access to space-occupying lesions such as tumors and vascular malformations located in the area of the tentorial notch, mediobasal temporal lobe, and para-midbrain is difficult. Lesions in this area are typically resected with supratentorial approaches demanding significant elevation of the temporal lobe or even partial lobectomy, or via a supracerebellar transtentorial approach. We introduce an alternative, the skull base infratranstentorial subtemporal approach (ITSTA), which provides excellent exposure of the incisural area while minimizing risk to the temporal lobe. METHODS: We included consecutive patients with pathology involving the area of the tentorial incisura, para-midbrain, and mediobasal temporal area who underwent surgery via ITSTA from 2012 to 2018. The approach includes partial mastoidectomy, temporal craniotomy, and tentorial section. Space obtained by mastoidectomy provides a sharp high-rising angle-of-attack, significantly diminishing the need for temporal lobe retraction. Surgeries were performed using microsurgical techniques, neuronavigation, and electrophysiological monitoring. Clinical presentation, tumor characteristics, extent of resection, complications, and outcome were retrospectively reviewed under a waiver of informed consent. RESULTS: Nine patients met inclusion criteria (five female, four male; mean age 44 years, range 7-72). They underwent surgery for removal of para-midbrain arteriovenous malformation (AVM, 3/9), medial tentorial meningioma (2/9), mediobasal epidermoid cyst (2/9), oculomotor schwannoma (1/9), or pleomorphic xanthoastrocytoma (PXA) of the fusiform gyrus (1/9). Three AVMs were removed completely; among six patients with tumors, gross total resection was achieved in three and subtotal resection in three. All surgeries were uneventful without complications. There were no new permanent neurological deficits. At late follow-up (mean 42.5 months), eight patients had a Glasgow Outcome Score (GOS) of 5. One 66-year-old female died 18 months after surgery for reasons not related to her disease or surgery. CONCLUSIONS: The ITSTA is a valuable skull base approach for removal of non-skull base pathologies located in the difficult tentorial-incisural parabrainstem area.

Sensitivity of the Mount Fuji Sign After Evacuation of Chronic Subdural Hematoma in Nonagenarians.

BACKGROUND: The Mount Fuji sign (MFS) is a radiological sign on computed tomographic scans depicting air between the frontal lobes. Air in this location indicates tension pneumocephalus (TP), considered a neurosurgical emergency.We evaluate the correlation between the MFS and perioperative mortality attributed to TP in nonagenarians who have undergone evacuation of chronic subdural hemorrhage (cSDH). MATERIALS AND METHODS: We retrospectively reviewed the records of nonagenarians who had cSDH evacuation between 2006 and 2015. Postoperative computed tomographic images were evaluated for findings consistent with the MFS. RESULTS: Of 45 patients, 15 patients (33%) had radiological MFS, and 3 patients (20%) with MFS required reoperation because of new blood collection. No patient required reoperation because of TP. Perioperative (30-day) mortality in patients demonstrating the MFS was 6.67% caused by cardiac arrhythmia versus 13.33% mortality in patients with no evidence of the MFS. CONCLUSION: Mount Fuji sign in nonagenarians after cSDH evacuation is not a specific sign of TP.