An isolated cavernous malformation of the sixth cranial nerve: A case report and review of literature.

BACKGROUND: Isolated cavernous malformation (CM) of the abducens nerve has not been reported in the literature. Herein, the authors address the clinical importance of these lesions and review the reported cases of CM from 2014 to 2020. CASE DESCRIPTION: A 21-year-old man presented with binocular diplopia and headache from 2 months before his admission. The neurological examination revealed right-sided abducens nerve palsy. The brain MRI revealed an extra-axial pontomedullary lesion suggestive of a CM. The lesion was surgically removed. During the operation, the abducens nerve was resected considering the lesion could not be separated from the nerve and an anastomosis was performed using an interposition nerve graft and fibrin glue. Pathological examination of the resected lesion revealed that it was originated from within the nerve. The patient's condition improved in postoperative follow-ups. CONCLUSION: Surgical resection of the cranial nerves CMs is appropriate when progressive neurological deficits are present. If the lesion is originated from within the nerve, we suggest resection of the involved nerve and performing anastomosis. Novel MRI sequences might help surgeons to be prepared for such cases and fibrin glue can serve as an appropriate tool to perform anastomosis when end-to-end sutures are impossible to perform.

Nerve-Sheath-Risen Neuroglial Cyst: Case Report and Review of the Literature.

BACKGROUND: Neuroglial cysts are rare intracranial lesions that are believed to originate from the sequestration of neural tube lining during embryogenesis. They can present anywhere within the neuraxis; however, their most common location is the frontal lobe. Cerebellopontine angle (CPA) neuroglial cysts are extremely rare and, to the best of our knowledge, there are no previous reports of a neuroglial cyst arising from cranial nerves. CASE DESCRIPTION: The current study presented a male adolescent with the reoccurrence of an intracranial cyst with symptoms of diplopia and facial numbness primarily treated as CPA arachnoid cyst with fenestration of the cyst 12 months prior to admission to our center. Different magnetic resonance imaging sequences showed a thin-walled extra-axial cyst at the right CPA without gadolinium enhancement. Direct visualization of the lesion revealed a cyst arising from the fifth cranial nerve sheath compressing the surrounding structures. The cyst was fenestrated, and a biopsy was taken from the cyst wall. The pathological analysis, along with specified histological markers, indicated the neuroglial nature of the cyst. CONCLUSIONS: The rising of a neuroglial cyst from the nerve sheath is a finding that brings other possible origins of neuroglial cysts into consideration.

Solitary aneurysm of the filum terminale artery: A case report and review of the literature.

BACKGROUND: We report a rare case of aneurysmal dilatation of filum terminale artery after resection of filum terminal myxopapillary ependymoma. CASE DESCRIPTION: The authors report a rare aneurysmal dilatation of the filum terminale artery following removal of a filum terminal myxopapillary ependymoma in a 10-year-old male. The patient presented with 6-month history of increasing back pain without a focal neurological deficit. Magnetic resonance (MR) showed an intradural filum terminale lesion that was completely excised. Three months later, the MR again revealed a lesion involving the filum terminale. During the second surgery, however, an aneurysmal dilation of the filum artery was found, which was coagulated and resected. Following the secondary surgery, the patient's symptoms gradually resolved, and he remains intact. CONCLUSION: Although rare, a true aneurysm after spinal surgery should be considered among the differential diagnostic consideration in the region of the filum terminale.

Spontaneous complete regression of hypothalamic pilocytic astrocytoma after partial resection in a child, complicated with Stevens-Johnson syndrome: a case report and literature review.

Pilocytic astrocytoma (PA) is the most common pediatric central nervous system glial neoplasm and the most common pediatric cerebellar tumor. The spontaneous regression that occurs after partial/subtotal resection is multifactorial, depending on multiple factors, as for the case of humoral and cell-mediated immune responses of the host to the implanted tumor. A 7-year-old boy was referred to a neurosurgery clinic with headache. Further imaging workup revealed hypothalamic PA. Partial resection of the lesions was performed with right-side pterional approach. The patient developed a severe panmucositis [Stevens-Johnson syndrome (SJS)] and respiratory failure plus conjunctivitis, due to phenytoin allergy. During the patient's 6-month follow-up, postoperative magnetic resonance imaging (MRI) revealed a residual tumor, and about 9 months later (at 15 months postoperatively), the MRI showed total regression of the tumor. Clinically, symptomatic PA may undergo spontaneous regression after partial resection. We report a well-documented case of spontaneous regression hypothalamic PA after partial resection that complicated with SJS. Immune system reaction in SJS may have a role in tumor behavior and spontaneous regression. Multiple studies confirmed spontaneous regression in PA after partial/subtotal resection. This phenomenon occurs due to humoral and cell-mediated host immune responses to the implanted tumor. The immune system reaction in SJS may have a role in tumor behavior and spontaneous regression.

Spontaneous corynebacterium spondylodiskitis in an immunocompetent patient: A case report and literature review.

BACKGROUND: Spontaneous Corynebacterium spondylodiskitis is an unusual diagnosis of spondylodiskitis, especially in healthy patients without any significant past medical history. MATERIALS AND METHODS: We describe the case of a 78-year-old man with progressive low back pain for 3 months, irradiating down the lower limbs through L5 and S1 root pathways, associated with distal muscle weakness in both lower limbs. He had no history of trauma or medical problems. Laboratory investigation revealed elevated serum C-reactive protein (CRP) and erythrocyte sedimentation rate, without leukocytosis. The magnetic resonance findings demonstrated an extensive L5-S1 spondylodiskitis and L4-L5 anterolisthesis. Prior to spinopelvic fixation and posterolateral fusion, a substantial debridement was performed. The obtained tissue samples were submitted to pathological and microbiological studies, which identified Corynebacterium infection. RESULTS: One month after surgery, the pain diminished dramatically and the CRP titer diminished significantly. CONCLUSION: Although cases are very rare, spontaneous Corynebacterium spondylodiskitis, with substantial invasion of the spine, may develop in patients lacking any history of medical or surgical problems.

An aneurysm at the site of the fenestration of the middle cerebral artery in a patient with multiple aneurysms: A case report.

BACKGROUND: Middle cerebral artery (MCA) fenestration is a very rare anatomical variant of the MCA, incidentally found during magnetic resonance or computed tomography angiography. It has an incidence of 0.6%. Unlike fenestration of the posterior cerebral arterial circulation, fenestration of the anterior cerebral arterial circulation has not been well described. METHODS: We present the rare case of a patient who was admitted for a ruptured aneurysm of the MCA arising at the site of the fenestration of the MCA and also an unruptured fusiform aneurysm of the right posterior communicating artery and a distal anterior cerebral artery (ACA) aneurysm. RESULTS: The patient underwent craniotomy with microsurgical aneurysm clipping and the previously undiagnosed ruptured aneurysm, at the site of the fenestration of the MCA, arose immediately. Postoperatively, the patient awoke without a deficit. After treatment of postoperative bacterial meningitis, he was discharged on the 26(th) postoperative day in good condition without any neurologic deficit. Six months after the first surgery, he was operated for the distal azygos ACA aneurysm. CONCLUSION: Anomalies of the intracranial vasculature are common, and we describe a rare case of left MCA fenestration with an associated ruptured aneurysm at the site of the fenestration. In the literature, cases of fenestration of the MCA are sporadically reported and are only incidental findings.

Hard calcified intrasellar schwannoma mimicking pituitary adenoma: a case report and review of the literature.

BACKGROUND: Intrasellar location of schwannoma is extremely rare, although intracranial schwannomas are common in the central nervous system. The aim of the present study is to describe a calcified intrasellar schwannoma case. MATERIALS AND METHODS: We represent a 45-year-old woman who had suffered from headaches; right side facial pain and visual disturbance which had worsen during the last week prior to admission. Physical examinations were normal except for the bitemporal visual field hemianopia which match with perimetry examination. MRI demonstrated an unusual seemingly calcified mass lesion in the sellar region which was mimicking pituitary macro adenoma. RESULT: Total resection of the tumor achieved through endoscopic transnasal transsphenoidal approach by extracapsular dissection and pathologic examination of the tumor revealed calcified schwannoma. CONCLUSION: The differential diagnoses of sellar and suprasellar lesions include pituitary adenomas, craniopharyngiomas, meningiomas, and many others. However, schwannoma is not usually included, because the occurrence of schwannoma in the sellar or suprasellar region is extremely rare. Only few cases of intrasellar schwannomas have been reported in the literature, all of which presented a suprasellar extension similar to that of our case. Fascinating surgical point is managing very firm tumor through transsphenoidal corridor which we handle it by very sharp, debulking and extracapsular removal.

Giant Leaking Colloid Cyst Presenting with Aseptic Meningitis: Review of the Literature and Report of a Case.

BACKGROUND: Colloid cysts are benign third ventricle lesions that need to be diagnosed correctly because of their association with sudden death. Chemical or aseptic meningitis is a rare presentation of a colloid cyst. METHODS: We present a case of a 69-year-old man with fever, alteration of mental status, and meningismus. Microbiological examination of the cerebrospinal fluid revealed aseptic meningitis. Brain imaging revealed a third ventricular colloid cyst with hydrocephalus. RESULTS: The tumor was resected via endoscopic intervention. There were no persistent operative complications related to the endoscopic procedure. CONCLUSIONS: Chemical or aseptic meningitis is an unusual clinical manifestation of a colloid cyst, complicating the differential diagnosis, especially in the elderly.

Bilateral Choroid Plexus Metastasis from Papillary Thyroid Carcinoma: Case Report and Review of the Literature.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. It has an indolent clinical course and favorable prognosis. Brain metastasis is uncommon and complicates about 0.1%-5% of PTCs. Metastasis to the choroid plexus of the lateral ventricles has been reported in 7 cases of thyroid malignancies, all of which were unilateral. METHODS: We report a case of a 52-year-old woman with a history of PTC who presented with severe headache, nausea and vomiting, right hemiparesis, and speech disturbance. Imaging studies depicted lesions in both lateral ventricles. RESULTS: The patient underwent microsurgical tumor resection. Histopathologic examination revealed choroid plexus metastasis from PTC. CONCLUSIONS: Metastases to the choroid plexus from extracranial tumors are very rare, with only a few cases reported thus far. A demographic analysis of these cases suggests there may be a tropism of some extracranial carcinomas, such as renal cell carcinoma, for choroid plexus, especially in the lateral ventricles. We report the eighth case of choroid plexus metastasis, but it is the first bilateral one arising from thyroid cancer.

Trigeminal Neuralgia Caused by Venous Angioma: A Case Report and Review of the Literature.

BACKGROUND: Trigeminal neuralgia typically occurs in the middle-aged to elderly population, is believed to be related to abnormal conduction within the trigeminal nerve, and is possibly is attributable to changes in myelin induced by pulsatile mechanical trauma from an adjacent vessel. At the point just before it enters the brainstem, there is a short segment at which nerve axons are still ensheathed in central myelin (produced by oligodendrocytes), but after a few millimeters, there is a transition to peripheral myelin (produced by Schwann cells). The region of this transition is called the Obersteiner-Redlich zone. It is thought that the area of the nerve containing the central form of myelin is especially susceptible to pathologic changes from vascular contact that result in demyelination and altered conduction. When associated with a venous angioma at the root entry zone, trigeminal neuralgia usually presents at a younger age. METHODS: We report a 34-year-old man with a complaint of left hemifacial stabbing pain in maxillomandibular area that was triggered by chewing and speaking. On examination, no neurologic deficit was detected. The pain was not relieved significantly, even with the administration of carbamazepine. Magnetic resonance imaging demonstrated venous angioma in the left cerebello-pontine region. RESULTS: Microvascular decompression was performed uneventfully. The patient's pain was completely relieved without neurologic deficits. CONCLUSION: It seems that the trigeminal neuralgia caused by venous angioma may occur in the younger population. In most cases, the vessel that caused compression can be identified with magnetic resonance imaging without the need for intensive conventional angiography.

Surgical Management of Giant Basilar Tip Aneurysm Associated with Moyamoya Disease: A Case Report and Literature Review.

BACKGROUND: We report the efficacy and safety of surgical treatment with the orbitozygomatic transsylvian approach and the rarity of accompanying subarachnoid hemorrhage, Terson syndrome, and ruptured giant basilar tip aneurysm in a patient affected by moyamoya disease with a good outcome. METHODS: A 40-year-old man with a history of exertional headache from childhood and hypertension diagnosed 5 years previously was referred to us with the presenting symptom of headache. After 1 day, he developed left hemiplegia, decreased level of consciousness, and blindness in the left eye. Imaging studies revealed a subarachnoid hemorrhage and giant basilar tip aneurysm. He underwent surgical clipping of the aneurysm using the orbitozygomatic transsylvian approach. RESULTS: With obvious improvement in strength and consciousness, the patient was discharged. Early diagnosis and treatment of the other possible complications of moyamoya disease were recommended. CONCLUSIONS: The rarity and different manifestations of moyamoya disease require individualized decision making with regard to cerebrovascular complications. Individualized decision making and the cooperation of medical teams are the mainstays of treatment.

Primary Meningeal Melanocytoma in the Left Temporal Lobe Associated with Nevus Ota: a Case Report and Review of the Literature.

BACKGROUND: Primary melanocytic neoplasms of the central nervous system are rare lesions arising from melanocytes of the leptomeninge that are found at highest density underneath the brain stem and along the upper cervical spinal cord. Thus most reported cases of meningeal melanocytomas are located in the posterior fossa and the spinal cord, and presentation of a supratentorial tumor is rare. METHODS: A 19-year-old man presented with a headache and seizure at our department. Neurological examinations were otherwise normal. On physical examination he had asymptomatic, bluish, speckled, and well-demarcated hyperpigmented macules on the left midface extraorally. A left temporal space-occupying lesion was seen on magnetic resonance imaging. The mass was hyperintense on T1-weighted images and isointense on T2-weighted images. Enhancement was shown on contrast-enhanced magnetic resonance imaging (MRI). The preoperative diagnosis was meningioma. RESULT: Gross complete resection was performed. Pathological studies led to the diagnosis of meningeal melanocytoma World Health Organization (WHO) grade I. The patient received oncologic consultation. Because total resection of the tumor was achieved and its histopathologic grade was benign (WHO grade I), radiotherapy was not advised for the patient and he followed up every 6 months. No tumor was seen on follow-up MRI one year after surgery. CONCLUSION: Presentation of meningeal melanocytoma in the supratentorial compartment is rare, and its combination with nevus Ota has been reported in very few cases. Although this lesion is benign, it might behave aggressively. Complete surgical resection of the lesion is the preferred therapeutic option.

Endoscopic Surgery in Nonhydrocephalous Third Ventricular Colloid Cysts: A Feasibility Study.

BACKGROUND: The aim of this study was to investigate the feasibility and effectiveness of endoscopic neurosurgery for patients with third ventricular colloid cysts but without ventriculomegaly. METHODS: Seventy-one patients with third ventricular colloid cysts were identified and recruited to this study. Eighteen of these patients did not have concomitant hydrocephalus and underwent primary endoscopic surgery for cyst resection. The surgical technique, the success rate, and patients' outcome were assessed and compared with another 53 patients with hydrocephalus who underwent similar procedures. Our study was performed in a retrospective basis, although in middle of our work we decided to study and follow nonhydrocephalus cases prospectively. RESULTS: The ventricular compartments were successfully cannulated and gross total resection and near total resection of the colloid cysts was achieved in all patients. There were no persistent operative complications related to the endoscopic procedure. The success rate for endoscopic surgery in patients without hydrocephalus was similar to its value in patients with hydrocephalus. CONCLUSIONS: Endoscopic resection of third ventricular colloid cyst in patients without hydrocephalus seems to be feasible, effective, and not contraindicated.