Dispersed Bone Spicules as a Cause of Postoperative Headache after Retrosigmoid Vestibular Schwannoma Surgery: A Myth?

Objectives Dispersion of bone dust in the posterior fossa during retrosigmoid craniectomy for vestibular schwannoma (VS) resection could be a source of meningeal irritation and lead to development of persistent postoperative headaches (POH). We aim to determine risk factors, including whether the presence of bone spicules that influence POH after retrosigmoid VS resection. Design Present study is a retrospective case series. Setting The study was conducted at a tertiary skull-base referral center. Participants Adult patients undergoing VS resection via a retrosigmoid approach between November 2017 and February 2020 were included for this study. Main Outcome Measures Development of POH lasting ≥ 3 months is the primary outcome of this study. Results Of 64 patients undergoing surgery, 49 had complete data (mean age, 49 years; 53% female). Mean follow-up time was 2.4 years. At latest follow up, 16 (33%) had no headaches, 14 (29%) experienced headaches lasting <3 months, 19 (39%) reported POH lasting ≥3 months. Twenty-seven (55%) patients had posterior fossa bone spicules detectable on postoperative computed tomography (CT). Age, gender, body mass index, length of stay, tumor diameter, size of craniectomy, the presence of bone spicules, or the amount of posterior petrous temporal bone removed from drilling did not differ significantly between patients with POH and those without. On multivariate logistic regression, patients with POH were less likely to have preoperative brainstem compression by the tumor (odds ratio [OR] = 0.21, p = 0.028) and more likely to have higher opioid requirements during hospitalization (OR = 1.023, p = 0.045). Conclusion The presence of bone spicules in the posterior fossa on postoperative CT did not contribute to headaches following retrosigmoid craniectomy approach for VS resection.

Staged embolisation of a giant torcular dural sinus malformation in a neonate

Torcular dural sinus malformations (tDSMs) represent a rare subset of paediatric cerebrovascular malformations and are often diagnosed antenatally via ultrasound. The management of these in utero lesions remains controversial as previous studies suggested elective termination of the pregnancy because of their presumably high mortality and severe long-term morbidity. However, more recent evaluations have suggested that the overall prognosis for infants harbouring these lesions may be much better than previously believed. As such, we present the case of a neonate with a giant tDSM, diagnosed in utero, who was treated postnatally via staged transarterial and transvenous embolisation to alleviate worsening obstructive hydrocephalus and brainstem compression. We provide details regarding the surgical approach and long-term neurological outcomes for this patient. To the best of our knowledge, this is one of the largest reported tDSM presented in the literature.

Endoscopic endonasal surgery for massive subarachnoid neurocysticercosis: illustrative case

BACKGROUND Subarachnoid neurocysticercosis (NCC) is associated with high morbidity and mortality rates. Conventional transcranial approaches and transventricular endoscopy have been previously reported for extraparenchymal NCC and ventricular NCC, respectively. By October 2019, endonasal endoscopic approaches had not been used for the treatment of NCC. OBSERVATIONS A 54-year-old-woman with NCC was admitted with acute neurological deterioration due to severe intracranial hypertension caused by massive subarachnoid NCC cysts, as evidenced on magnetic resonance imaging (MRI) with great brainstem compression. The case was discussed, and an endoscopic endonasal resection of the NCC cysts was scheduled. The diagnosis was confirmed by pathological anatomy. There were no complications in the surgery, with marked neurological improvement. Control MRIs demonstrated a significant reduction of NCC cysts. LESSONS Minimally invasive approaches are an excellent alternative for skull-base tumoral and infectious pathology. Prior knowledge of the pathophysiology and the authors’ experience in the management of patients with NCC allowed them to propose this approach, with optimal results.

Tumor-Related and Patient-Related Variables Affecting Length of Hospital Stay Following Vestibular Schwannoma Microsurgery

Objective: Review a single institution’s vestibular schwannoma (VS) microsurgery experience to determine (1) correlations between demographics, comorbidities, and/or surgical approach on hospital length of stay (LOS) and discharge disposition and (2) trends in surgical approach over time. Methods: Retrospective case series from a multidisciplinary skull base program at a tertiary care, academic hospital. All adult (>18 years) patients undergoing primary microsurgery for VS between 2008 and 2018 were included. Results: A total of 147 subjects were identified. Surgical approach was split between middle fossa (MF) (16%), retrosigmoid (RS) (35%), and translabyrinthine (TL) (49%) craniotomies. For the 8% of patients had other than routine (OTR) discharge. Mean LOS was significantly longer for patients undergoing RS than either MF or TL. Brainstem compression by the tumor was associated with longer LOS as were diagnoses of chronic obstructive pulmonary disease (COPD) and peripheral vascular disease (PVD). For all discharges, the 40 to 50- and 50 to 60-year-old subgroups had significantly shorter LOS than the 70-years-and-older patients. For the 92% of patients routinely discharged, there was a significantly shorter LOS in the 40 to 50-year-olds compared to the 70-years-and-older patients. There was a significant shift in surgical approach from RS to TL over the study period. Conclusion: Over 90% of VS microsurgery patients were routinely discharged with a median hospital LOS of 3.2 days, both of which are consistent with published data. There is an inverse relationship between age and LOS with patients older than 70 years having significantly longer LOS. Brainstem compression, COPD, PVD, and the RS approach negatively affect LOS. Level of Evidence 4

Fenestration of intracranial neurenteric cyst: A case report

Background: Neurenteric cysts are rare congenital lesions of endodermal origin which result from the failure of the neurenteric canal to close during embryogenesis. The majority of neurenteric cysts occur in the spinal cord, though in rare instances can occur intracranially, typically in the posterior fossa anterior to the pontomedullary junction (80%) or in the supratentorial region adjacent to the frontal lobes (20%). Case Description: We present the case of a 75-year-old woman with an extra-axial cystic lesion centered in the premedullary cistern causing brainstem compression. The lesion was later histopathologically confirmed to be a neurenteric cyst. She presented initially with a 4-month history of worsening headache, dizziness, and unsteady gait. We performed a left retrosigmoid craniotomy for cyst fenestration/biopsy with the aid of operating microscope and stealth neuronavigation. Following the procedure, the patient recovered without complications or residual deficits. Conclusion: This case illustrates the successful fenestration of an intracranial neurenteric cyst with good clinical outcome. We present the pre- and post-operative imaging findings, a technical video of the procedure, histopathological confirmation, and a brief review of the relevant clinical literature on the topic.

Prediction of Hearing Preservation in Vestibular Schwannoma Surgery According to Tumor Size and Anatomic Extension

Objective Vestibular schwannoma (VS) surgery is feasible for various tumor sizes that are inappropriate for wait and scan or radiosurgery. The predictive value of 2 grading systems was investigated for postoperative hearing preservation (HP) in a large series. Study Design Retrospective analysis. Setting Neurosurgical patient database of the University of Erlangen was queried between 2014 and 2017. Methods Retrospective single-center analysis on 138 VSs operated on via a retrosigmoidal approach. The mean tumor size was 20.4 mm (SD, 7.6 mm) with fundal infiltration in 67.4%. The overall resection rate was 93.5%. Tumors were classified preoperatively by the 3-tier Erlangen grading system depending on size or the anatomically based 4-tier Koos grading system. Results Preoperative hearing preservation was found in 70.3% of patients and was significantly correlated to tumor size ( P = .001). For Erlangen grading, a mean postoperative serviceable hearing preservation rate of 32% was achieved: 83.3% for tumors <12 mm, 30.3% for tumors between 12 and 25 mm, and 5.3% for tumors >25 mm. In contrast, according to Koos grading, postoperative serviceable hearing preservation was 100% for grade 1 tumors (meatal), 35.6% for grade 2 (cisternal), 23.1% for grade 3 (brainstem contact), and 21.7% for grade 4 (brainstem compression). Of the total cohort, 86% had normal or nearly normal postoperative facial function (House-Brackmann grades 1 and 2). Conclusion Surgery on small VSs can achieve excellent hearing preservation. Different grading has a significant influence on and correlates with postoperative hearing preservation. Tumor size seems more important than anatomic relationship.

Medial Acoustic Tumors: Special Considerations: 2-Dimensional Operative Video

Medial acoustic tumors are a rare distinct type of vestibular schwannoma having distinguished clinical and radiological features.1 Originating medially in the cerebellopontine angle without extending into the lateral internal auditory meatus, they are frequently giant in size at presentation in younger patients with a relatively preserved hearing, while they have other neurological deficits from cerebellar or brainstem compression and associated hydrocephalus. Imaging typically shows a cystic tumor with local mass effect and an internal auditory canal filled with cerebrospinal fluid.1,2 Surgical resection of theses schwannoma is particularly challenging not only due to their size and hypervascularity, but also given their particular arachnoidal rearrangement inducing marked adherence to the brainstem and facial nerve.2 The treatment is surgical resection, despite, however, their giant size hearing preservation should be sought and is attainable.1–5 Transmastoid approach with squeletonization and reflection of the transverse sigmoid sinus provides lateral exposure avoiding cerebellar retraction.6 In this report, we demonstrate the specific surgical considerations applied to the resection of a giant medial acoustic tumor in a 40-yr-old patient presenting with ataxia, vertigo, facial paresthesia, and intact hearing. The patient agreed to the surgery and photography. Image at 1:44 © Ossama Al-Mefty, used with permission; Image at 8:21 from Dunn et al,2 used with permission from JNSPG.

Management of The Posterior Cerebral Fossa Ependymomas

Background Posterior fossa brain ependymomas are one of the most devastating forms of human illnesses which are more common in children. Brainstem compression, herniation and death are the risks with tumours in this critical location. Patients and Methods: A retrospective study including 50 patients with posterior fossa ependymoma were performed at the Neurosurgery Department in Ait IDDIR University Hospital between the period of January 2005 and December 2015 . In each case, diagnosis was made clinically and confirmed radiologically and histo-pathologically.. All patients received the adjuvant treatment Results Out of 50 patients, 30 (60%) patients were males and 20 (40%) were females. The mean age was 24 years (ranged 5 months –47 years) ; we identified 29 (58%) children and 21 (42%) adults,. Ventriculo-peritoneal shunts were placed in all our patients, the total tumor excision was done to 35% and the partial tumor excision was done to 65% patients. The most common complications were as follows: Shunt malfunction : 4% , operative cavity hematoma 6%, CSF fistula 4%, deterioration of Cerebellar syndrome 6%, Cerebellar Mutism 2%, Mixed nerves palsy 4% and early post operative deaths 10%. Tumor architecture was classified as classic (Grade II) in 35 (70%) cases and anaplastic (Grade III) in 13(26%) cases. Adjuvant treatment regimens following resection included radiation therapy only (72%) for 36 patients including children above and adults and chemotherapy only (36%) for 9 children below 4 years and 9 recurrent tumors. During follow-up period, recurrence occurred in 27% 11patients out of 41patients .Five patients died (10%). Conclusion The surgical treatment of posterior fossa tumours still represents a challenge for neurosurgeons, Radical surgery with preservation of vital structures is the treatment of choice in patients with Posterior Cerebral Fossa ependymomas.Our experience shows the accepted results, complications and surgical outcome in relation to previous clinical studies.