Neurobrucellosis presenting as an infected cerebellopontine cistern epidermoid cyst.

Neurobrucellosis is a rare complication of brucella infection which presents as meningitis, meningoencephalitis, subdural empyema, brain abscess, myelitis, and radiculo- neuritis. We report the first case of neurobrucellosis presenting as an infected cerebellopontine cistern epidermoid cyst in a young immunocompetent male who presented with fever and acute raised intracranial pressure. MRI brain showed an extra-axial mass in the right cerebellopontine angle cistern with peripheral rim enhancement and diffusion restriction. Emergency surgery unveiled a well-encapsulated lesion containing thick pus and keratinous material, confirming an infected epidermoid cyst. Intriguingly, the culture revealed Brucella infection, but the source of the infection remained unclear.

Malignant transformation of residual posterior fossa epidermoid cyst to squamous cell carcinoma.

Malignant transformation of intracranial epidermoid cysts to squamous cell carcinoma is a rare occurrence and only a small number have been reported to date. MRI recurrence in combination with neurological decline should prompt surgery to exclude malignant transformation. Herein, we describe our experience of such a case and contribute to the evolving series within the literature.

Extra-axial medulloblastoma in cerebello-pontine angle: A report of a rare case with literature review.

Medulloblastoma is quite uncommon in the adult population and even rarer in extra-axial site in cerebello-pontine (CP) angle. In this report, a 23-year-old male patient with a two month history of deafness, nausea, vomiting and ataxia is presented. Clinical and radiological findings demonstrated a heterogeneously enhanced extra-axial lesion in the right CP angle. Total excision was performed and the histopathological features of medulloblastoma were confirmed. After surgery, the patient had no neurological deficit and the audiometric findings were improved. In addition, he underwent adjuant radiotherapy and no sign of metastatic mass was observed in follow-up spinal cord MRI. Although extremely rare, medulloblastoma must be considered in the differential diagnosis of extra-axial CP angle lesions.

Remote supratentorial intraparenchymal bleed after posterior fossa surgery: A rare occurrence.

Background: Intraparenchymal hemorrhage at the operative site is one of the major complications of brain surgery. It is unusual to occur at a site remote from the operative site, but when it happens, it may cause significant morbidity and mortality. Case Description: We report the case of a 27-year-old male who presented with complaints of paresthesias over the left side of his face and decreased hearing from the left ear for two years. His radiology was suggestive of a large left cerebellopontine angle epidermoid cyst. The patient underwent left retro mastoid suboccipital craniotomy and near-total excision of the epidermoid cyst. The immediate postoperative non-contrast computed tomography scan of the brain was suggestive of no hematoma at the operated site but a remote left parafalcine frontoparietal intraparenchymal bleed, which was managed conservatively. At two months follow-up, he had no neuro deficits, and magnetic resonance imaging of the brain was suggestive of near-total excision of the epidermoid cyst with resolving left parafalcine frontoparietal bleed. Conclusion: We report this case due to the unique case observation of an intracranial bleed at a remote site rather than at the operated site.

Cranial Conundrum: An Unusual Case of an Epidermoid Cyst in the Prepontine Cistern.

We present a fascinating case of a patient who suffered from persistent headaches for three months due to an epidermoid cyst located in the prepontine cistern. Epidermoid cysts are a very uncommon type of intracranial tumor, known for their slow growth and gradual onset of neurological symptoms. In this particular case, our patient, a 35-year-old, experienced a headache that was accompanied by dizziness, photophobia, and pain when moving their eyes. Further imaging revealed a cystic lesion in the prepontine cistern, which had a mass effect on the pons. After confirming the lesion was likely an epidermoid cyst through an MRI, the patient underwent surgery to have it removed. We hope to highlight the rarity of this type of tumor and its unique features when viewed through imaging.

A Rare Case Report of an Intradural Left Cerebellopontine Angle Chordoma.

Intracranial intradural chordomas are rare entities constituting 1 to 3% of primary bone tumors. The mainstay of treatment remains aggressive resection of the lesion followed by adjuvant radiation therapy. We hereby report a case of a 70-year-old gentleman with intracranial, intradural chordoma arising from the left cerebellopontine angle. We hope to add to the existing minimal literature on this subject by highlighting this case, the first reported one from Asia.

Introducing the Posterior Condylar Emissary Vein as an Effective Surgical Landmark for Optimizing the Standard Retrosigmoid Approach: An Anatomo-Imaging Study.

OBJECTIVE: There is a lack of definite anatomical landmarks for the inferior extension of the standard retrosigmoid approach. In this study, we evaluated whether the posterior condylar emissary vein (PCEV) can be used as an intraoperative landmark for optimizing the surgical corridor. METHODS: We performed the standard retrosigmoid approach on 5 formalin-fixed and latex-injected cadaveric specimens and measured the distance between the PCEV near its bony canal and the vertebral artery (VA). In addition, vascular reconstructions of thin-sliced preoperative computed tomography (CT) scans were studied in 40 patients and the relationship between these 2 vessels was evaluated. An illustrative case is also included. RESULTS: The PCEV was consistently identified on both sides of cadaveric specimens and in 87.5% and 82.5% of the left and right sides of the included CT scans, respectively. The average distance between the part of the PCEV near its osseous canal and the VA was measured to be between 8.4 mm and 8.6 mm in the specimens and between 9.2 mm and 9.3 mm in the CT scans. This distance offers a safe and effective plane of dissection during the standard retrosigmoid approach and allows easy access to the foramen magnum. CONCLUSIONS: The PCEV near its bony canal proved to be an easy, straightforward, safe, and effective operative landmark with which the surgeon can extend the soft tissue dissection and bony exposure towards the foramen magnum. This maneuver provides ample access to the cisterna magna for cerebrospinal fluid drainage and increases visibility and surgical maneuverability to the entire cerebellopontine angle.

Surgical Management of Cerebellopontine Angle (CPA) Lipoma Presenting As Trigeminal Neuralgia: A Case Report.

The report details an instance of a 35-year-old male, who came to our hospital with a two-year history of typical trigeminal neuralgia on the left side, predominantly in V2 and V3 dermatomes. The patient was started on medications, but pain could not be controlled by increasing doses and adjuvant medications over the last three months. A lesion was seen on the MRI in the left cerebellopontine angle (CPA) region, hyperintense on T1W and decreased on fat-suppressed imaging, characteristic of lipoma. Being an intractable case, surgery was offered to the patient. Following this, a left retromastoid suboccipital craniectomy was done, and lipoma was excised, decompressing the trigeminal nerve and relieving neuralgia symptoms. In the post-op period, the patient was completely pain-free, but he developed left-sided hearing loss and left facial palsy, Brackmann grade 4, which improved to Brackmann grade 3 on the three-month follow-up.

Facial Nerve Schwannoma: The Rare/Great Mimicker of Vestibular Schwannoma/Neuroma.

Schwannomas are benign tumors arising from Schwann cells which are a protective casing of nerves, composing myelin sheath and can develop in any nerve where Schwann cells are present. Most common are vestibulocochlear nerve schwannomas. Facial nerve schwannomas (FNSs) are uncommon tumors involving seventh nerve of which geniculate ganglion involvement is most common. Clinical presentations and the imaging appearances of FNSs are influenced by the topographical anatomy of the facial nerve and vary according to the segments involved. We report a case of 73-year-old man presenting with right side facial weakness of lower motor neuron type involvement. Computed tomography and magnetic resonance imaging are clinching the diagnosis. An early diagnosis is important in containing the disease facilitating early surgical intervention.

Combined Microscopic-Endoscopic Transmastoid Resection of a Petrous Meningioma: 2-Dimensional Operative Video.

Petrous meningiomas are defined as tumors with a basal dural attachment on the posterior surface of the petrous bone.1 Their insertion can be anterior to the meatus (petrous apex meningiomas), or posterior to the meatus, with associated hyperostotic bony invasion either pre- or retro-meatal.2 These meningiomas are amenable to curative surgical removal and have better surgical outcomes than more medially located true petroclival meningiomas that originate medial to the fifth nerve.2-4 They, however, remain challenging because of their close relationship to critical neurovascular structures in the cerebellopontine angle.5 The posterior petrous meningiomas might reach a significant size with compression of the cerebellum, the brainstem, and involvement of the cranial nerves, and extend posteriorly to the transverse sigmoid sinus.2,6 Transmastoid approach with skeletonization and lateral reflection of the transverse sigmoid sinus provides a superb exposure without cerebellar retraction.6,7 The ease and complete resection of the tumor and invaded bone can be facilitated by combined microscopic-endoscopic techniques. We demonstrate these principles through the resection of a petrosal meningioma in a 56-yr-patient who presented with headaches, nystagmus, and mild cerebellar signs. The patient consented to the procedure. Image at 1:36 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, ©LWW, 1998.

Resection of a Dumbbell-Shaped Facial Nerve Schwannoma With Preservation of Facial Nerve Function Through the Extended Middle Fossa Approach: 2-Dimensional Operative Video.

Facial nerve schwannomas are rare and can arise from any segment along the course of the facial nerve.1 Their location and growth patterns present as distinct groups that warrant specific surgical management and approaches.2 The management challenge arises when the facial nerve maintains good function (House-Brackmann grade I-II).3 Hence, a prime goal of management is to maintain good facial animation. In large tumors, however, resection with facial nerve function preservation should be sought and is achievable.4,5 While tumors originating from the geniculate ganglion grow extradural on the floor of the middle fossa, they may extend via an isthmus through the internal auditory canal to the cerebellopontine angle forming a dumbbell-shaped tumor. Despite the large size, they may present with good facial nerve function. These tumors may be resected through an extended middle fossa approach with preservation of facial and vestibulocochlear nerve function. The patient is a 62-yr-old man who presented with mixed sensorineural and conductive hearing loss and normal facial nerve function. Magnetic resonance imaging (MRI) revealed a large tumor involving the middle fossa, internal auditory meatus, and cerebellopontine angle. The tumor was resected through an extended middle fossa approach with a zygomatic osteotomy and anterior petrosectomy.6 A small residual was left at the geniculate ganglion to preserve facial function. The patient did well with hearing preservation and intact facial nerve function. He consented to the procedure and publication of images. Image at 1:30 © Ossama Al-Mefty, used with permission. Images at 2:03 reprinted from Kadri and Al-Mefty,6 with permission from JNSPG.

Endoscopic assisted microsurgical removal of cerebello-pontine angle and prepontine epidermoid.

Cerebello-pontine(CP) angle and prepontine epidermoid tumors are challenging lesions because they grow along the subarachnoid spaces around the very important neurovascular structures and often extend into the supratentorial compartment. They have typically been removed through a variety of anterolateral, lateral, and posterolateral cranial base microsurgical approaches. Sometime they were removed by the endoscope-assisted microneurosurgical (EAM) techniques. Here we report a CP angle and preontine epidermoid tumor extended to supratentorial compartment presented with trigeminal neuralgia that was removed by pure endoscopic visualization through retrosigmoid retromastoid lateral suboccipital approach. (The method of using endoscope along with surgical instruments passing along the sides of endoscope is termed as Endoscope-Controlled Microsurgery-ECM.) So far our knowledge, in the literature this type of report is probably very rare.