1/9. 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 = pressure (Clic here for more details about this article) |
2/9. 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 = 2keywords = pressure (Clic here for more details about this article) |
3/9. Medulloblastomas in neurofibromatosis type 1. Case report and literature review.A 6-year-old girl, previously diagnosed with neurofibromatosis type 1 (NF-1) presented with ataxia and symptoms of raised intracranial pressure. Diagnostic work up disclosed a posterior fossa tumor. Histopathological study of the excised neoplasm showed a cerebellar medulloblastoma. We review the current literature and suggest that the association of medulloblastoma with NF-1 is not a chance occurrence, and that it might be pathogenically related. We propose that medulloblastoma should be added to the list of malignancies that are apt to occur in NF-1.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
4/9. Unusual localization of a choroid plexus papilloma in a 4-year-old female.choroid plexus papillomas are rare tumors that are confined to areas in which the choroid plexus is normally located. In children, choroid plexus papillomas are predominantly located in the lateral ventricles. Clinically they present with signs of raised intracranial pressure, such as vomiting and increasing head size. Here we report on the clinical, radiologic, and histologic findings of a 4-year-old female who was found to have a tumor in the posterior fossa that had all the histologic hallmarks of a choroid plexus papilloma. This tumor did not originate from the roof of the fourth ventricle as expected but from the ependymal lining covering the median rostral medulla near the pontomedullary junction, a location that so far has not been reported.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
5/9. Rapid neurological deterioration associated with minor head trauma in chronic hydrocephalus.CASE REPORT: An 8-year-old developmentally normal boy (status: post third ventriculostomy and resection of posterior fossa low-grade glioma 4 years earlier and with known history of ventriculomegaly/arrested hydrocephalus) presented to the emergency room with vomiting and lethargy after a minor head trauma. Computed tomography scan of the head revealed no acute changes since previous studies. However, the patient's neurological status rapidly declined in the emergency room, where an emergency ventriculostomy demonstrated increased intracranial pressure. The patient's clinical condition improved over 24 h: he underwent placement of a ventriculoperitoneal shunt without complications and was discharged intact. DISCUSSION: The pathogenesis of rapid neurological decline associated with minor head trauma in chronic hydrocephalus is reviewed.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
6/9. 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 = 1keywords = pressure (Clic here for more details about this article) |
7/9. Unsuccessful third ventriculostomy for occlusive hydrocephalus.For non-communicating hydrocephalus, neuroendoscopic third ventriculostomy has become a major choice. But sometimes, the procedure results in failure. Typically, impairment of a distal CSF absorption, a preexisting arachnoid membrane just below the fenestrated site and a glial scarring of fenestrated site were pointed out as a factors of failure. On the other side, the intraventricular pressure dynamics of a functioning third ventriculostomy is in the process of study. Recently some reports have noticed the importance of the flow of CSF into the prepontine cistern, mimicking the flow through the aqueduct of Sylvius. We report an unsuccessful trial of third ventriculostomy in a case with huge posterior fossa tumor.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
8/9. Multiple supratentorial epidural haematomas after posterior fossa surgery.Postoperative epidural haematoma distant to a site of craniotomy is a rare but possibly hazardous complication. We report a 31-year-old female who presented with a history of chronic hydrocephalus due to fourth-ventricular plexus papilloma. Following resection of the posterior fossa tumour with intraoperative placement of a ventricular drainage, she consecutively developed four supratentorial epidural haematomas at different locations, all necessitating evacuation. The clinical manifestations ranged from subtle neurological deficits to signs of tentorial herniation; the ultimate outcome was complete recovery. Rapid tapering of CSF pressure after long-standing hydrocephalus and clotting disorders could be implicated as causative factors. We stress the importance of early postoperative CT scan and optimal management of ventricular pressure and coagulation status to detect and prevent this possibly life-threatening complication.- - - - - - - - - - ranking = 2keywords = pressure (Clic here for more details about this article) |
9/9. prenatal diagnosis of a giant congenital primary cerebral hemangiopericytoma.Congenital primary intracranial hemangiopericytomas are exceptionally rare tumors. We present a case of a fetus, with the prenatal sonogram at 33 weeks of gestation revealing a large cerebral tumor. Because of the enlarged head, a cesarean section was performed. The tumor was confirmed by postnatal ultrasound, magnetic resonance imaging (MRI) and biopsy. Elevated intracranial pressure and hemorrhage led to death on the 11th day. autopsy revealed a 10x9 cm large inhomogeneous tumor located centrally, mainly in the posterior fossa. histology showed a hypercellular and hypervascular tumor with extended necrosis and high mitotic rate. The tumor cells were positive for vimentin and CD34 antigens and negative for several neurological markers, desmin and CD31. The diagnosis of a congenital primary cerebral hemangiopericytoma was confirmed.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |