Spontaneous ventriculostomy: report of three cases revealed by flow-sensitive phase-contrast cine MR imaging.
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Spontaneous ventriculostomy is a rare condition that occurs with the spontaneous rupture of a ventricle, resulting in a communication between the ventricular system and the subarachnoid space. Three cases of spontaneous ventriculostomy through the floor of the third ventricle that occurred in cases of chronic obstructive hydrocephalus are presented. The communication was identified via flow-sensitive phase-contrast cine MR imaging. Spontaneous ventriculostomy is probably a result of a rupture of the normally thin membrane that forms the floor of the third ventricle and, with long-standing obstructive hydrocephalus, creates an internal drainage pathway that spontaneously compensates for the hydrocephalus. (+info)
Endoscopic aqueductal plasty via the fourth ventricle through the cerebellar hemisphere under navigating system guidance--technical note.
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A 1-year 8-month-old boy presented with isolated fourth ventricle after ventriculoperitoneal shunting for hydrocephalus associated with ventricular and subarachnoid hemorrhage. The therapeutic endoscope was inserted through the thin left cerebellar hemisphere. Endoscopic aqueductal plasty was performed via the enlarged fourth ventricle under guidance from a navigating system. Endoscopic aqueductal plasty via the fourth ventricle under navigating system guidance is a useful procedure enabling less invasive surgery for isolated fourth ventricle associated with slit-like ventricle after shunt placement. (+info)
Secondary amenorrhea caused by hydrocephalus due to aqueductal stenosis : report of two cases.
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Amenorrhea is rarely presented as a manifestation of endocrinological disturbances in patients of chronic hydrocephalus. We describe two cases of secondary amenorrhea caused by hydrocephalus due to aqueductal stenosis. Two female patients of age 30 and 20 yr presented with amenorrhea and increasing headache. Magnetic resonance images revealed marked, noncommunicating hydrocephalus without any tumorous lesion. In one patient, emergent extraventricular drainage was necessary because of progressive neurological deterioration. Each patient underwent surgical intervention for the hydrocephalus-ventriculoperitoneal shunt and endoscopic third ventriculostomy. Both resumed normal menstruation continuing so far with further normal menstrual bleeding. These two cases and others reported in the literature indicated that the surgical intervention for hydrocephalus resolves amenorrhea in all the cases of amenorrhea due to hydrocephalus. The suspected role of the surgery is the correction of increased intracranial pressure, which is an important pathogenetic factor in the development of amenorrhea. (+info)
Sylvian aqueduct syndrome as a sign of acute obstructive hydrocephalus in children.
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Eight cases of obstructive hydrocephalus manifesting palsy of upward gaze and other features of the Sylvian aqueduct syndrome are reported. During the crisis of intracranial hypertension, all of them developed upward gaze palsy and variable abnormalities of the convergence mechanism such as paralysis, spasm, and convergence nystagmus. The frequent apparent blindness was probably related to gaze paralysis, since visual evoked responses were present. All these ocular abnormalities disappeared after shunting. Periaqueductal dysfunction on the basis of raised intracranial pressure is postulated as the possible mechanism for the above ocular manifestations. The 'setting sun' sign is frequently seen in infants and children with hydrocephalus and has been considered in the past to result from displacement of eyeballs by pressure from the orbital roof plate. Our observations would suggest periaqueductal dysfunction rather than the mechanical displacement as the possible mechanism for this sign. (+info)
Tight Sylvian cisterns associated with hyperdense areas mimicking subarachnoid hemorrhage on computed tomography--four case reports.
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Four patients with supratentorial mass lesions (two chronic subdural hematomas, one acute epidural hematoma, and one acute subdural hematoma) showed hyperdense sylvian cisterns on computed tomography (CT). Association of subarachnoid hemorrhage was suspected initially, but was excluded by intraoperative observation or postoperative lumbar puncture. CT showed disappearance of the hyperdense areas just after evacuation of the mass lesions. The hyperdense areas are probably a result of the partial volume phenomenon or concentrations of calcium deposits rather than abnormally high hematocrit levels, which were not found in these patients. (+info)
Unusual arachnoid cyst of the quadrigeminal cistern in an adult presenting with apneic spells and normal pressure hydrocephalus--case report.
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A 67-year-old woman was admitted to our clinic with symptoms of normal pressure hydrocephalus, lower cranial nerve pareses, and pyramidal and cerebellar signs associated with respiratory disturbances. Computed tomography (CT) and magnetic resonance imaging revealed a 4.7 x 5.4 cm quadrigeminal arachnoid cyst causing severe compression of the tectum and entire brain stem, aqueduct, and cerebellum, associated with moderate dilation of the third and lateral ventricles. Emergency surgery was undertaken due to sudden loss of consciousness and impaired breathing. The cyst was totally removed by midline suboccipital craniotomy in the prone position. Postoperatively, her symptoms improved except for the ataxia and impaired breathing. She was monitored cautiously for over 15 days. CT at discharge on the 18th postoperative day revealed decreased cyst size to 3.9 x 4.1 cm. Histological examination confirmed the diagnosis of the arachnoid cyst of the quadrigeminal cistern. The patient died of respiratory problems on the 5th day after discharge. Quadrigeminal arachnoid cysts may compress the brain stem and cause severe respiratory disturbances, which can be fatal due to apneic spells. Patients should be monitored continuously in the preoperative and postoperative period until the restoration of autonomous ventilation is achieved. (+info)
Vasopressin release by nicotine: the site of action.
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1. In cats anaesthetized with chloralose the release of neurohypophysial hormones was examined after injection of nicotine into the cerebral ventricles or cisterna magna or its topical application through perspex rings to the ventral surface of the brain stem. The release was measured by assaying the hormones in samples of venous blood. 2. Injected into a lateral or the third cerebral ventricle, nicotine (0.5 to 1 mg) produced release of vasopressin without oxytocin. When the aqueduct was cannulated, preventing access to the fourth ventricle and to the subarachnoid space, this release did not occur. 3. Vasopressin was also released without oxytocin when nicotine (0.25 to 2 mg) was injected into the subarachnoid space through the cisterna magna. With this route of administration the nicotine did not enter any part of the ventricular system. 4. Applied through paired perspex rings placed across the ventral surface of the brain stem, nicotine again produced release of vasopressin without ocytocin. The amount of nicotine placed in each ring was usually 80 mug, but a release was obtained with 10 mug and in one experiment with as little as 5 mug. 5. The bilateral region on the ventral surface of the brain stem where nicotine acts when producing release of vasopressin lies lateral to the pyramids and in a longitudinal direction, 6 to 9 mm caudal to the trapezoid bodies. 6. The vasopressin release by nicotine injected intraventricularly or intracisternally, or applied topically to the ventral surface of the brain stem was not due to absorption of nicotine into the blood stream, nor to blood pressure effects. 7. It is concluded that nicotine acts on the ventral surface of the brain stem probably by activating the central projection to the supra-optic and possibly also the paraventricular nuclei of afferent pathways in the sinus and vagus nerves which control the release of vasopressin in response to changes in blood volume or distribution. (+info)
Effect of endoscopic third ventriculostomy on neuropsychological outcome in late onset idiopathic aqueduct stenosis: a prospective study.
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OBJECTIVE: To undertake a prospective study of the long term neuropsychological outcome in patients with late onset idiopathic aqueduct stenosis (LIAS) after endoscopic third ventriculostomy. METHODS: Six patients with LIAS were evaluated pre- and postoperatively using magnetic resonance imaging (MRI) and standardised psychometric testing procedures. Endoscopic third ventriculostomy was done using standard surgical techniques. The mean long term follow up was 81.2 weeks. RESULTS: Preoperatively, all patients had cognitive impairment, four of them showing deficits in several cognitive domains. After endoscopic third ventriculostomy, all patients improved clinically and had ventricular size reduction on MRI. Postoperative neuropsychological testing showed that five patients achieved normal or near normal cognitive functions, and one improved moderately. CONCLUSIONS: Endoscopic third ventriculostomy caused a substantial improvement in the neuropsychological deficit of LIAS patients. This was also true for patients with enlarged ventricles that might be diagnosed radiologically as "arrested hydrocephalus." (+info)