Tumours of the third ventricle in children.
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Experience with 25 cases of tumour of the third ventricle in children is reviewed. The majority of the lesions were infiltrating astrocytomas of the anterior and mid-portions of the third ventricle. These tumours were generally inoperable. However, other tumours within the third ventricle were benign, encapsulated, and resectable. Surgical exposure was carried out through one of three routes: posterior fossa, transcallosal, or subfrontal. The radiological criteria by which the operative approach is determined are discussed. (+info)
Effect of cerebrospinal fluid shunts on intracranial pressure and on cerebrospinal fluid dynamics. 2. A new technique of pressure measurements: results and concepts. 3. A concept of hydrocephalus.
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Part 2 describes measurements of intracranial cerebrospinal fluid (CSF) pressure in 18 adult patients with CSF shunts, all pressure measurements being referred to a horizontal plane close to the foramina of Monro. All 18 patients had normal CSF pressure by lumbar puncture; however, in one patient an intracranial pressure of +280 mm was subsequently measured after pneumoencephalography. Twelve patients had pre-shunt CSF pressures measured intracranially: 11 ranged from +20 to +180 mm H(2)O and one was +280 mm H(2)O in the supine position. In the upright posture nine patients had values of -10 to -140 mm H(2)O, while three others were +60, +70, and +280 mm H(2)O. After CSF shunting in these 18 patients the pressures were -30 to +30 mm H(2)O in the supine position and -210 to -370 mm in the upright position. The effect of posture on the siphoning action of these longer shunts in the erect, adult patient is a major uncontrollable variable in maintenance of intracranial pressure after shunting. Other significant variables are reviewed. In Part 3 a concept of the hydrocephalus phenomenon is described. Emphasis is placed on the pressure differential (P(d)) and force differential (F(d)) causing pre-shunt ventricular enlargement and post-shunt ventricular size reduction. The site of P(d), which must be very small and not to be confused with measured ventricular pressure, P, must be at the ventricular wall. (+info)
Resistance to drainage of cerebrospinal fluid: clinical measurement and significance.
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By infusing saline intrathecally at a constant rate until a new steady-state cerebrospinal fluid (CSF) pressure is attained, one can estimate clinically the apparent resistance (Ra) to drainage of CSF in mm saline/ml./minute. This intrathecal saline infusion test (ITSIT) was performed 36 times on 29 patients with diverse intracranial problems, and the results were analysed and, in most cases, compared with the pneumoencephalogram and the isotope cisternogram. The ITSIT is a safe, simple test to estimate Ra, but factors which are difficult to control (occult leaks from the subarachnoid space; independent fluctuations of CSF pressure) limit its reliability and clinical usefulness. If closely correlated with the clinical syndrome, the pneumoencephalogram, and the isotope cisternogram, an ITSIT may identify decisively the patient who needs a shunt. In addition the ITSIT offers another method by which to investigate the pathophysiological mechanisms of the various states of intracranial hypertension. Results from the test performed on four patients with intracranial hypertension of unknown cause (pseudotumor cerebri) suggest that the underlying mechanism in this condition is probably an impediment to normal CSF drainage. (+info)
Periaqueductal dysfunction (the Sylvian aqueduct syndrome): a sign of hydrocephalus?
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A patient with hydrocephalus due to aqueductal occlusion is described in whom the Sylvian aqueduct syndrome appeared during a sudden increase in intracranial pressure. The ocular signs resolved completely when the hydrocephalus was relieved. Marked dilatation of the posterior part of the third ventricle and of the rostral aqueduct with axial displacement of these structures was demonstrated radiologically. It is suggested that the ocular signs in this case were the result of periaqueductal dysfunction due to assimilation and dilatation of the aqueduct, with secondary tentorial block. This abnormality may be the cause of the similar abnormalities commonly found in noncommunicating hydrocephalus in both infants and adults. (+info)
Why do central arachnoid pouches expand?
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Three cases of progressive hydrocephalus, two occurring in infants and one in a 12 year old girl who also exhibited precocious puberty, were found to be associated with large arachnoid pouches originating within the posterior fossa. The pathogenesis of such cysts is discussed with special reference to the possibility that their progressive distension results from CSF pulsations of venous origin. Both a direct method of treatment (opening the cyst into the adjacent subarachnoid space) and an indirect one (insertion of a ventriculo-atrial shunt) have been used with success. (+info)
Benign aqueduct stenosis in adults.
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A series of 55 cases is described in which hydrocephalus associated with non-neoplastic narrowing of the Sylvian aqueduct produced symptoms for the first time in adult life. The clinical features of the patients and their investigation are described and discussed. (+info)
Sequelae to pneumoencephalography.
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Fifty patients were examined clinically and neurologically for seven days after pneumoencephalography. Headache was present in 78%, neck stiffness in 34%, pyrexia in 38%, vomiting in 34%, tachycardia in 74%, a change in the level of consciousness in 18%, and abnormal neurological signs in 30%. Of the 13 patients with epilepsy, there was an increased frequency of seizures in four, associated with increased EEG epileptiform activity in three. EEG abnormality either appeared or increased in 74% of cases on the second day after the air study. A mechanism for the production of these sequelae is proposed. It is concluded that these findings indicate that in most cases an organic brain syndrome follows pneumoencephalography. (+info)
Dementia paralytica: deterioration from communicating hydrocephalus.
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Five patients suffering from dementia paralytica who failed to improve or deteriorated after one or several high dosage courses of penicillin, had pneumoencephalographic patterns suggesting communicating hydrocephalus. Measurements of the ventricular index, ratio of cella media to width of the temporal horn, and the callosal angle differed from that in seven cases of dementia paralytica with associated cerebral atrophy. An isotope cisternogram in three cases with communicating hydrocephalus further confirmed a blockage of the cerebrospinal fluid (CSF) at the parasagittal subarachnoid space. Three patients exhibited the full syndrome of gait apraxia, incontinence, and pyramidal tract signs associated with a severe degree of dementia. Shunting of the CSF in three cases was followed by immediate improvement in two, one in a longlasting way. No active parenchymal inflammation was observed in any of three brain biopsy samples taken during surgery, except for leptomeningeal fibrosis in one. Chronic leptomeningitis in dementia paralytica may impair subarachnoid CSF absorption with subsequent communicating hydrocephalus. Progression or inadequate responses after therapeutic dose of penicillin in dementia paralytica should prompt investigation for this complication as an alternative, effective treatment could be offered. (+info)