Journal of neurosurgery
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Journal of neurosurgery · Aug 1975
Computer-assisted analysis of intraventricular pressure after mannitol administration.
The effect of prolonged mannitol infusion upon intraventricular pressure was investigated with the aid of a specially-designed automatic digital recording system; the data recorded were processed off-line by a minicomputer. The character of the pressure curves is thought to result from interaction between the mannitol effect and the observed system's shifting equilibrium position, which is caused by other factors. The character of the pressure curves prior to mannitol infusion must be taken into consideration in estimating the actual effect of the drug; the authors suggest that in certain cases it might be possible to decrease further the rate of mannitol administration. The advantages of statistical approach to the evaluation of intracranial pressure variations are discussed.
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Journal of neurosurgery · Jun 1975
Scanning electron microscopy of the ventricular system in normal and hydrocephalic rabbits. Preliminary report and atlas.
The author used the scanning electron microscope to study the ependyma in six control rabbits and six rabbits made hydrocephalic by infusion of silicone oil into the cisterna magna. The ependymal lining of the third ventricle, head of the caudate nucleus, superior angle of the caudate, and atrium of the lateral ventricle was examined. In the hydrocephalic animals, clusters of cilia emanating from the ependyma over periventricular white matter become separated; the author believes this is secondary to ingrowth of new ependymal cell processes covered with microvilli. ⋯ No such changes occur over gray matter masses since their surfaces are not deformed by moderate ventricular dilatation. The morphological alterations in the ependyma that occur in moderate hydrocephalus do not appear to be simply manifestations of ependymal destruction but rather suggest a modification in its function from that of a surface capable of propelling cerebrospinal fluid to one capable of increased transfer of transventricular fluid. As hydrocephalus progresses, compensation may fail because of the relative decrease in microvilli so that the cell surface provides a less efficient mechanism for absorption.
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The authors describe a case of human cerebral mucormycosis following open head trauma and craniotomy, and discuss possible roles of steroids and antibiotic therapy in its pathogenesis. They suggest that the common usage of prolonged broad-spectrum chemoprophylaxis in head trauma may require critical review.
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Journal of neurosurgery · Mar 1975
Comparative StudyEffects of mannitol and steroid therapy on intracranial volume-pressure relationships in patients.
The intracranial volume-pressure response was measured in 61 patients undergoing continous monitoring of intraventicular pressure. This test, which determlnes the increase in intracranial pressure induced by an addition of 1 ml in ventricular CSF volume in 1 sencond, yields information concerning spatial compensation in patients with intracranial space-occupying processes. ⋯ In patients with intracranial hypertension, intravenous mannitol (0.5gm/kg) and intramuscular betamethasone (26 mg) both reduce the volume-pressure response significantly more than they reduce intracranial pressure. This suggests that these agents favorably alter the configuration of the volume-pressure curve.