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.

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.

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.

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.

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.