Spontaneous chronic subdural hematoma of the posterior fossa: A case report.

Background: Chronic subdural hematoma (CSH) in the posterior fossa is extremely rare and only a few cases have been reported in the literature. We report a case of CSH in the posterior fossa successfully treated with a single burr hole surgery. Case Description: A 66-year-old woman who underwent anticoagulation therapy and was suffering, in the past 3 weeks from headache, vertigo, and gait ataxia. Screening with magnetic resonance imaging demonstrated infratentorial CSH on the right cerebellar hemisphere. Coagulation was normalized and the hematoma was evacuated through a burr hole irrigation. The symptoms resolved completely within a few days. Postoperative computed tomography showed a normal postoperative appearance and resolution of hematoma. She was discharged 1 week later without any neurological deficits. Conclusion: CSH in the posterior fossa is an extremely rare condition. Due to the limited number of reports, the optimal treatment is yet unknown. In cases with coagulation disorders, less invasive and early treatment should be considered. More studies are needed to define the best management for this pathology and cases must be individualized according to each patient's particularities.

Transtentorial spread of glioblastoma multiforme to cerebellopontine angle - A rare case report.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common central nervous system malignant tumor in adults with 48.3% of cases. Despite it, the presence of transtentorial spread is uncommon, with few patients reported in the literature. In this study, the authors report a case of GBM transtentorial spread to cerebellopontine angle after resection and adjuvant treatment. CASE DESCRIPTION: A 55-year-old male patient with GBM, previously submitted to surgical resection and adjuvant treatment with radiotherapy and quemotherapy. Fourteen months after the first surgery, he developed headaches associated with dysphagia and dysphonia. Magnetic resonance imaging showed a recurrence of the left parietal lesion and a new mass in the right cerebellopontine angle. The patient underwent successful surgical resection of both lesions. Chemotherapy was maintained after the surgery. CONCLUSION: To the best of our knowledge, there are few cases of GBM metastasis to the cerebellopontine angle reported in the literature. Surgical management should be considered in cases of intracranial hypertension and patients with good performance status.

Reproducibility of a new classification of the anterior clinoid process of the sphenoid bone.

BACKGROUND: Pneumatization of the anterior clinoid process (ACP) affects paraclinoid region surgery, this anatomical variation occurs in 6.6-27.7% of individuals, making its preoperative recognition essential given the need for correction based on the anatomy of the pneumatized process. This study was conducted to evaluate the reproducibility of an optic strut-based ACP pneumatization classification by presenting radiological examinations to a group of surgeons. METHODS: Thirty cranial computer tomography (CT) scans performed from 2013 to 2014 were selected for analysis by neurosurgery residents and neurosurgeons. The evaluators received Google Forms with questionnaires on each scan, DICOM files to be manipulated in the Horos software for multiplanar reconstruction, and a collection of slides demonstrating the steps for classifying each type of ACP pneumatization. Interobserver agreement was calculated by the Fleiss kappa test. RESULTS: Thirty CT scans were analyzed by 37 evaluators, of whom 20 were neurosurgery residents and 17 were neurosurgeons. The overall reproducibility of the ACP pneumatization classification showed a Fleiss kappa index of 0.49 (95% confidence interval: 0.49-0.50). The interobserver agreement indices for the residents and neurosurgeons were 0.52 (0.51-0.53) and 0.49 (0.48-0.50), respectively, and the difference was statistically significant (P < 0.00001). CONCLUSION: The optic strut-based classification of ACP pneumatization showed acceptable concordance. Minor differences were observed in the agreement between the residents and neurosurgeons. These differences could be explained by the residents' presumably higher familiarity with multiplanar reconstruction software.

Adult Nasoethmoidal Encephalocele Corrected by Supraorbitary Approach: Case Report and Literature Review

Encephalocele is a protrusion of the central nervous system elements through a defect in the dura mater and in the cranium. The prevalence of encephalocele ranges from 0.08 to 0.5 per 1,000 births. The posterior encephaloceles are more common in North America and Europe, while frontal defect is frequently found in Asia. The present paper describes a 26-year-old male patient presenting with cerebrospinal fluid leak and meningitis symptoms. He was diagnosed with congenital nasoethmoidal encephalocele and treated surgically using a supraorbital approach without complications.

Brain Metastasis of Wilms Tumor in Adult.

BACKGROUND: Wilms tumor is a rare renal tumor in adults. To the best of our knowledge, only a small number of cases of brain metastasis have been reported in the literature. We report the case of a 29-year-old female with headache and dizziness, with a parietal mass and pathologic diagnosis of Wilms tumor metastasis. CASE DESCRIPTION: The patient was admitted with a 3-month history of lumbar pain and 2 months of progressive headache associated with dizziness. Abdomen magnetic resonance imaging showed a renal mass. Post nephrectomy, the neurologic signs worsened and a head magnetic resonance imaging presented in the right parietal lobe, convexity, heterogeneous lesion with little perilesional edema. The patient underwent a complete surgical resection with success. The adjuvant treatment was chemotherapy. CONCLUSIONS: Few cases of brain metastasis of Wilms tumor exist in the literature. Surgical management is considered in cases with intracranial hypertension or focal signs. The adjuvant treatment options are immunotherapy and chemotherapy.

Intradural disc herniation at the L1-L2 level: A case report and literature review.

BACKGROUND: Why are intradural disc herniations (IDHs) (0.3% of all discs) so infrequent? One explanation has been the marked adherence of the posterior longitudinal ligament (PLL) to the ventral wall of the dura. Variability in symptoms and difficulty in interpreting magnetic resonance (MR) images with/without contrast make the diagnosis of an IDH difficult. Here, we reported a patient with an L1-L2 IDH and appropriately reviewed the relevant literature. CASE DESCRIPTION: A 57-year-old male presented with chronic low back and 1 month's duration of the left thigh pain. The lumbar MR with/without contrast demonstrated an IDH at the L1-L2 level, resulting in spinal cord compression. At surgery, the disc herniation was appropriately resected, the dura was closed, and an interbody fusion with pedicle screw fixation was performed. Postoperatively, the patient clinically improved. CONCLUSION: IDHs are rare, being seen in only 0.3% of all cases. MR findings, performed with/without contrast, may help signal the presence of an IDH. MR findings include a hypointense structure inside the dura; the "hawk beak" sign (e.g., beak-like mass with ring enhancement at the intervertebral disc space); the Y sign (e.g., ventral dura split into ventral dura and arachnoid by disc material); an abrupt loss of continuity of the PLL; a diffuse annular bulge with a large posterocentral extrusion; and an typical crumbled appearance of disc (e.g., "crumble disc sign"). At surgery, both the extradural and intradural components of the disc must be excised.

Brain metastasis of Merkel cell carcinoma - A rare case report.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin tumor. In our knowledge, only 30 cases of brain metastasis were reported in literature. The authors report a case of 57-year-old male with elevated intracranial pressure signs, which a frontal mass with pathological diagnosis of MCC. CASE DESCRIPTION: A 57-year-old male was admitted with a 3-month history of progressive headache, associated with nausea and dizziness. The magnetic resonance imaging showed a left frontal lobe, parasagittal, and nodular lesion with perilesional edema. The patient underwent complete surgical resection with success. The adjuvant treatment was radiotherapy and chemotherapy. CONCLUSION: In our knowledge, there is a little number of cases of MCC reported in literature. Surgical management is considered in cases with intracranial hypertension or focal signs. The adjuvant treatment options are immunotherapy and radiotherapy.

Orbital Schwannoma: Case Report and Review

Orbital schwannomas are rare, presenting a rate of incidence between 1 and 5% of all orbital lesions. Their most common clinical symptoms are promoted by mass effect, such as orbital pain and proptosis. The best complementary exam is the magnetic resonance imaging (MRI), which shows low signal in T1, high signal in T2, and heterogeneous contrast enhancement. The treatment of choice is surgical, with adjuvant radiotherapy if complete resection is not possible. We report the case of a 24-year-old male patient with orbital pain and proptosis, without previous history of disease. The MRI showed a superior orbital lesion compatible with schwannoma, which was confirmed by biopsy after complete resection using a fronto-orbital approach.

Trigeminal Neuralgia Caused by Cerebellopontine Angle Tumors: Surgical Series

Introduction Cerebellopontine angle (CPA) tumors represent an important cause of persistent and refractory trigeminal neuralgia (TN). It is believed that between 1 and 9.9% of the cases of patients presenting with TN painful manifestation are caused by space-occupying lesions. Objective The objective of the present study is to describe the clinical and surgical experience of the operative management of patients presenting with secondary type TN associated with CPA tumors. Method An observational investigation was conducted with data collection from patients with secondary type TN associated with CPA tumors who were treated with surgical resection of the space-occupying lesion and decompression of the trigeminal nerve from January 2013 to November 2016 in 2 different centers in the western region of the state of São Paulo, Brazil. Results We operated on 11 consecutive cases in which TN was associated with CPA during the period of analysis. Seven (63.6%) patients were female, and 4 (36.4%) were male. Seven (63.6%) patients presented with right-side symptoms, and 4 (36.4%) presented with left-side symptoms. After 2 years of follow-up, we observed that 8 (72.7%) patients showed a complete improvement of the symptoms, with an excellent outcome, and that 3 (27.3%) patients showed an incomplete improvement, with a good outcome. No patient reported partial improvement or poor outcome after the follow-up. There was no operative mortality. Conclusion Cerebellopontine angle tumors represent an important cause of TNandmust be included in the differential diagnosis of patients presenting with refractory and persistent symptoms. Surgical treatment with total resection of the expansive lesion and effective decompression of the trigeminal nerve are essential steps to control the symptoms.

Clival SubduralHematoma after Drainage of Concomitant Intracranial and Spinal Cord Subdural Hematomas ­ Rare Case Report

Concomitant traumatic spinal cord and intracranial subdural hematomas associated with a retroclival hematoma are very uncommon. Their pathophysiology is not totally elucidated, but one hypothesis is the migration of the hematoma from the head to the spine. In the present case report, the authors describe the case of a 51-year-old man presenting with headache, nauseas and back pain after a head trauma who presented with intracranial and spinal cord subdural hematomas. Drainage was performed but, 1 week later, a retroclival subdural hematoma was diagnosed. The present paper discusses the pathophysiology, the clinical presentation, as well as the complications of concomitant traumatic spinal cord and intracranial subdural hematomas associated with a retroclival hematoma, and reviews this condition.

Transtentorial Approach for Parahippocampal Gyrus Arteriovenous Malformation Resection: 3-Dimensional Operative Video.

Medial temporal basal arteriovenous malformations (AVMs) have complex anatomy. They usually drain to the basal vein of Rosenthal, and arterial feeders can arise from the anterior choroidal artery and its branches, or from the posterior cerebral artery. If the AVM is more posterior in the parahippocampal gyrus, there is a predominance of arterial feeders arising from P2P or P3 segments of the posterior cerebral artery. As posterior AVMs are difficult to reach using anterior approaches, the supracerebellar transtentorial approach provides a direct pathway to the malformation, allowing better visualization and exposure of the vascular anatomy. In this video, we present a 29-yr-old woman with a left parahippocampal AVM with P2P arterial feeders and Rosenthal basal vein drainage. The patient had three months of moderate headache and two abrupt seizures before admission. Emergency computed tomography showed intraventricular hemorrhage. Magnetic resonance imaging and cerebral angiography revealed an AVM located in the parahippocampal gyrus, posterior to pulvinar thalamus. The patient underwent microsurgical treatment in semi-sitting position using a supracerebellar and infratentorial approach with transtentorial resection. The AVM was completely removed, and the patient recovered without neurological deficits. The authors present a 3-dimensional video of the microsurgical steps required to perform a transtentorial approach for AVM resection in the parahippocampal gyrus. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any type of medical publications in conferences and/or scientific articles.

Microsurgery for Upper Basilar Tip Aneurysm With Intraoperative Rupture: 3-Dimensional Operative Video.

In the last years, a shift from the microsurgical treatment to an endovascular therapy in patients with basilar apex aneurysm has been settled, part of this phenomenon is related to the significant tendency of vital perforators to be involved in the aneurysm dissection and clipping, which can implicate unfavorable outcomes. Nevertheless, microsurgical treatment remains the treatment that can provide the superior rates of stable and durable aneurysm occlusion, which is most important to young patients.In this video, we present the case of a 45-yr-old female patient who complained of a sudden and severe headache and presented with progressive lethargy during the following 3 d.At admission, computed tomography did not show abnormal findings. However, cerebrospinal fluid analysis showed erythrocytes and corroborated the clinical suspicion of spontaneous subarachnoid hemorrhage. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any type of medical publications in conferences and/or scientific articles.Angiography and magnetic resonance imaging revealed a saccular basilar apex aneurysm. It showed a wide neck as well as a lobulated dome with upward and slightly left projection. The aneurysm did not involve angiographically visible thalamoperforator arteries, which allowed the microsurgical treatment by the fronto-orbitozygomatic approach. However, during the interpeduncular cistern dissection, an intraoperative rupture of the aneurysm occurred. This video exemplifies the steps required to manage an intraoperative rupture of a basilar apex aneurysm.

Microsurgical Clip Placement for a Giant Anterior Communicating Artery Aneurysm With Intraluminal Thrombus: 2-Dimensional Operative Video.

Giant brain aneurysms account for approximately 5% of all intracranial aneurysms. Although treatment modalities can vary widely, none is ideal for every patient. Endovascular treatment is usually preferred, especially when the large size of the aneurysm limits visualization of the brain parenchyma and parent vessels that arise from the aneurysm, making surgical clip placement across the neck a difficult task. However, despite the higher chances of morbidity, microsurgery is an effective treatment modality due to lower recurrence rates. Surgically, a wide neck, calcifications, or atheroma are complicating factors to be considered while planning the best treatment. Thus, with an appropriate case selection, a favorable outcome is feasible in most cases. Here, we present the case of a 27-yr-old female who presented with a severe headache for 7 mo and 3 mo of progressive left temporal vision loss, which was confirmed by visual field perimetry using the Humphrey visual field analyzer. Magnetic resonance angiography and digital subtraction cerebral angiography showed an anterior communicating artery complex inferiorly and medially oriented aneurysm measuring 25.4 × 16.5 mm, with a 3 mm neck. It was fed by the right A1, associated with a hypoplastic left A1, incorporating the proximal right and left A2 segments, with an intraluminal thrombus and causing mass effect on the optic chiasm and hypothalamus. This video demonstrates the microsurgical steps required to perform this operation, through a right orbitozygomatic craniotomy. At a 3-mo follow-up, the patient was neurological intact without complaints. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any type of medical publications in conferences and/or scientific articles.

Microsurgical Clipping of Ruptured Distal Posterior Inferior Cerebellar Artery Aneurysm: 3-Dimensional Operative Video.

The distal posterior inferior cerebellar artery (PICA) is a rare site of aneurysm formation. Only small case series and case reports regarding surgical treatment are found in the literature.The PICA is divided into 5 segments (anterior medullary, lateral medullary, tonsilomedullary, telovelotonsillary, and cortical), and the distal ones represent the most complex, due to anatomic variations. We present a case of a 69-yr-old female patient who has suffered from a sudden and intense occipital headache, associated with nausea and vomiting. CT scan showed intraventricular hemorrhage, and further investigation with MRI and MR Angiography revealed a small distal PICA aneurysm, at the superior part of the medial aspect of the left cerebellar tonsil. Digital angiography has demonstrated the aneurysm at the tonsilomedullary segment of the PICA. In this 3-dimensional video, the authors show the microsurgical clipping of a saccular distal PICA aneurysm in the close relation to a choroidal branch, performed by median suboccipital craniotomy. Step-by-step of the dissection, relevant surrounding anatomy and aneurysm clipping is demonstrated. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any type of medical publications in conferences and/or scientific articles.

Microsurgical Resection of Craniocervical Dermoid Cyst by Far Lateral Approach: Case Report and Literature Review

Introduction Intracranial dermoid tumors represent a rare clinical entity that accounts for 0.04 to 0.6% of all intracranial tumors. Their location in the posterior fossa is uncommon. Objectives To report the case of a young woman with a posterior fossa dermoid cyst treated by right far lateral approach. Case Report A 17-year-old woman presenting with swallowing difficulties for 6 weeks was referred for a neurological investigation. Amagnetic resonance imaging (MRI) scan showed a hyperintense T1-weighted large expansive lesion occupying the posterior fossa and compressing the anterior face of the brain stem and cerebellum. The patient underwent surgical treatment by right far lateral approach with decompression of vascular and neural structures. The patient presented an uneventful recovery, and was discharged home on the fourth postoperative day without any additional neurological deficits. The anatomopathological analysis confirmed the diagnosis of dermoid cyst. Conclusion The far lateral approach is a safe and feasible route to appropriately treat large posterior fossa dermoid cysts. Decompression of vascular and neural structures is essential to achieve good symptom control.

Angular and metric analysis of the neural structures in the cerebellopontine angle.

INTRODUCTION: The cerebellopontine angle (CPA) is a subarachnoid space in the lateral aspect of the posterior fossa. In this study, we propose a complementary analysis of the CPA from the cerebellopontine fissure. METHODS: We studied 50 hemi-cerebelli in the laboratory of neuroanatomy and included a description of the CPA anatomy from the cerebellopontine fissure and its relationship with the flocculus and the 5th, 6th, 7th, and 8th cranial nerves (CN) origins. RESULTS: The average distance from the 5th CN to the mid-line (ML) was 19.2 mm, 6th CN to ML was 4.4 mm, 7-8 complex to ML was 15.8 mm, flocculus to ML was 20.5 mm, and flocculus to 5th CN was 11.5 mm, additionally, and the diameter of the flocculus was 9.0 mm. The angle between the vertex in the flocculus and the V CN and the medullary-pontine line was 64.8 degrees. DISCUSSION: The most common access to the CPA is through the retrosigmoid-suboccipital region and this approach can be done with the help of an endoscope. The anatomy of origins of neural structures tends to be preserved in cases of CPA lesions. CONCLUSION: Knowledge of the average distances between the neural structures in the cerebellar-pontine fissure and the angular relationships between these structures facilitates the use of surgical approaches such as microsurgery and endoscopy.