1/23. Exophytic juvenile pilocytic astrocytomas of the posterior fossa.In children, posterior fossa juvenile pilocytic astrocytomas are common tumors. Radiologically, primarily extra-axial brainstem pilocytic astrocytomas are uncommon and extra-axial cerebellar pilocytic tumors are exceptional. We report two cases of such exophytic tumors, contrasting their presentation, imaging appearance, and prognosis. We also report the radiographic features of posterior fossa juvenile pilocytic astrocytomas from a 5-year review of our institutional experience.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
2/23. Relative pupil-sparing oculomotor nerve palsy as the presenting sign of posterior fossa meningioma.We report a case of relative pupil-sparing oculomotor paresis initially attributed to ischemia because weakness of other cranial nerves was minimal and dismissed as insignificant. neuroimaging eventually revealed a posterior fossa meningioma. The neurologic symptoms and signs disappeared immediately after resection of the tumor. The third nerve palsy was attributed to deformation of the brainstem. This case reinforces the importance of neuroimaging even in patients who have apparently isolated oculomotor palsy with features not classic for an ischemic etiology.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
3/23. Segmental myoclonus as the sole manifestation of a choroid plexus papilloma in the posterior fossa. Case report.The authors describe the case of a 22-year-old woman with involuntary contractions of the sternocleidomastoid and trapezius muscles that resulted in turning movements of the head. The jerks displayed the clinical and neurophysiological characteristics of segmental myoclonus (SM) restricted to muscles supplied bilaterally by the first four cervical segments. magnetic resonance imaging disclosed a tumor in the midline above the cisterna magna that was later histologically proven to be a choroid plexus papilloma. The patient's involuntary movements did not extend to other muscle groups or, in particular, to the palate, as one might have expected in the case of brainstem lesions. myoclonus was the sole clinical manifestation of the tumor in this patient; other signs and symptoms invariably reported in other cases of posterior fossa papilloma, such as increased intracranial pressure or cranial nerve palsies, were absent. Release from suprasegmental control is suggested as a possible pathophysiological mechanism in this case of SM.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
4/23. Peduncular hallucinations associated with large posterior fossa meningiomas.Peduncular hallucinosis may be observed in patients with thalamic or brain stem ischemia or hemorrhage, while it has been less often described in association with brain stem or cerebellar tumors. We report in this paper two cases associated with large posterior fossa meningiomas. In the first patient hallucinosis appeared preoperatively as a result of brain stem compression and ceased after the tumor removal. In the second patient hallucinosis occurred after the surgery, as a result of surgical trauma with local brain stem edema, and ceased 4 days after treatment with desamethasone and carbamazepine.- - - - - - - - - - ranking = 4keywords = brain (Clic here for more details about this article) |
5/23. Regression of symptomatic syringomyelia after resection of posterior fossa tumour.syringomyelia associated with posterior fossa tumours is a very infrequent combination of pathological entities. The few cases which have been reported generally were asymptomatic in respect of the spinal cavitations. The authors report on a 36-year-old woman with a large extradural posterior fossa epidermoid tumour with a concomitant holocord symptomatic syringomyelia. Some of her symptoms were clearly attributed to the intraspinal cavitation. The lesions were both diagnosed by magnetic resonance imaging (MR). The patient did well after surgery of the brain lesion, with an objective improvement in her neurological status and a complete resolution of the syrinx documented by the MR 7 months after tumour removal.syringomyelia in this case could be explained by blockage of the cerebrospinal fluid (CSF) circulation at the foramen magnum which in turn resulted in cranio-spinal pressure dissociation. This led to an accumulation of extracellular fluid (ECF) in the central canal, starting cavitation. Consequently, the syrinx was slowly expanded by the long-standing "slosh" effect of the systolic pressure waves. However, also via a distortion mechanism within the posterior fossa a pathologically plugged obex could have contributed to syrinx formation by means of preventing drainage of fluid from the ventricular CSF system.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
6/23. Anterior transpetrosal approach for pontine cavernous angioma--case report.A 58-year-old male patient presented with headache and unsteady gait. magnetic resonance imaging revealed hemorrhage from a pontine cavernous angioma. The patient experienced stepwise aggravation of symptoms due to repeated hemorrhages. We decided to surgically remove the pontine cavernous angioma through an anterior transpetrosal approach, since the angioma and hematoma were located near the ventrolateral surface of the pons. The brain stem was incised at a site caudal to the trigeminal nerve and the hematoma and angioma were totally removed. No additional neurological deficits were observed following surgery. brain stem cavernous angiomas are usually removed via a trans-fourth ventricle or lateral suboccipital approach. However, these approaches may not be appropriate if the angioma is located ventrally to the pons. We propose that the anterior transpetrosal approach is the method of choice for ventrally located pontine cavernous angioma.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
7/23. MRI findings in a case of a superficial siderosis associated with an ependymoma.We present the imaging findings of superficial siderosis of the central nervous system associated with an ependymoma of the posterior fossa in a patient who presented with progressive bilateral sensorineural hearing loss and cerebellar ataxia. The ependymoma was a homogeneous well-defined mass of the fourth ventricle without hydrocephalus. Secondary siderosis due to chronic bleeding from the ependymoma appeared as linear hypointensity delineating the surface of the cortex, thin and subtle on spin-echo T2-weighted images, thick and obvious on gradient-echo T2-weighted images.- - - - - - - - - - ranking = 1.6243209649314keywords = central nervous system, nervous system (Clic here for more details about this article) |
8/23. Intramedullary spinal cavernous malformation following spinal irradiation. Case report and review of the literature.There is a growing body of evidence in the literature suggesting that cavernous malformations of the central nervous system may develop after neuraxis irradiation. The authors discuss the case of a 17-year-old man who presented with progressive back pain and myelopathy 13 years after undergoing craniospinal irradiation for a posterior fossa medulloblastoma. Spinal magnetic resonance (MR) imaging, performed at the time of his initial presentation with a medulloblastoma, demonstrated no evidence of a malformation. Imaging studies and evaluation of cerebrospinal fluid revealed no evidence of recurrence or dissemination. Spinal MR imaging demonstrated an extensive lesion in the thoracic spine with an associated syrinx suggestive of a cavernous malformation. A thoracic laminectomy was performed and the malformation was successfully resected. Pathological examination confirmed the diagnosis. The patient did well after surgery and was ambulating without assistance 6 weeks later. To the best of the authors' knowledge, this is the second reported case in the literature and the first in the young adult age group suggesting the de novo development of cavernous malformations in the spinal cord after radiotherapy. An increased awareness of these lesions and close follow-up examination are recommended in this setting.- - - - - - - - - - ranking = 1.6243209649314keywords = central nervous system, nervous system (Clic here for more details about this article) |
9/23. Reverse brain herniation during posterior fossa surgery.Posterior fossa tumors are commonly associated with obstructive hydrocephalus. Relieving the raised intracranial pressure by draining the cerebrospinal fluid presents the possibility of reverse herniation of the brain. A 5-year-old male child with a diagnosis of posterior fossa space-occupying lesion and hydrocephalus was scheduled for craniectomy in the prone position. After craniectomy, the surgeons placed an intraventricular shunt catheter to drain out cerebrospinal fluid in an attempt to reduce the tense brain so as to facilitate easy dissection of the tumor. The patient had sudden and severe bradycardia followed by asystole. A diagnosis of reverse coning was made. Immediately, the surgeon injected 10-15 mL normal saline into the ventricles. There was a spontaneous return of the sinus rhythm and the rest of the course of surgery was uneventful. We present this case showing a rare phenomenon and its successful management.- - - - - - - - - - ranking = 6keywords = brain (Clic here for more details about this article) |
10/23. Extraneural metastases of infratentorial glioblastoma multiforme to the peritoneal cavity.This report describes two autopsy-proven cases of a rare complication of infratentorial glioblastoma multiforme (GBM): metastatic seeding of the peritoneal cavity through ventriculoperitoneal (VP) shunts. Patient 1 was a 13-year-old boy with a pontine GBM, and Patient 2 was a 9-year-old girl with a thoracolumbar spinal cord GBM. autopsy of both patients demonstrated leptomeningeal gliomatosis encasing the spinal cord and basal structures of the brain, in addition to peritoneal and omental metastases. The pattern of abdominal metastasis seen in these patients is typical of tumors that directly seed the peritoneal cavity and implicates the VP shunt as the vehicle of extraneural spread. Although a rare occurrence, extraneural metastases should be sought in patients with glioma with VP shunts who demonstrate increased abdominal girth, unexplained weight gain, or persistent abdominal pain.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
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