Journal of neurosurgery
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Journal of neurosurgery · Feb 1994
Case ReportsTranscranial Doppler ultrasound findings in cerebral venous sinus thrombosis. Case report.
Transcranial Doppler ultrasound (TCD) findings are described in a patient with acute thrombosis of the sagittal venous sinus. The TCD finding of prominent venous signals adjacent to the middle cerebral artery gave the first indication of the diagnosis, which was subsequently confirmed by computerized tomography. Awareness of the possible TCD findings in patients with a similar history may lead to a more rapid diagnosis of cerebral venous sinus thrombosis.
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Journal of neurosurgery · Feb 1994
Case ReportsHydrocephalus due to villous hypertrophy of the choroid plexus in the lateral ventricles. Case report.
A case is reported of hydrocephalus due to overproduction of cerebrospinal fluid (CSF) caused by villous hypertrophy of the choroid plexus in the lateral ventricles. A 7-year-old girl with mental retardation developed gait disturbance; hydrocephalus and a Dandy-Walker cyst were detected on computerized tomography. She was initially treated with a ventriculoperitoneal shunt; however, shunting failed to control the hydrocephalus. ⋯ The patient was therefore diagnosed as having hydrocephalus induced by overproduction of CSF, which was controlled by resection of the choroid plexus. Histological examination showed the structure typical of normal choroid plexus. This is a rare case of villous hypertrophy of the choroid plexus in which MR imaging assisted in the diagnosis.
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Journal of neurosurgery · Feb 1994
Biodegradable polymers for controlled delivery of chemotherapy with and without radiation therapy in the monkey brain.
Sustained drug delivery by biodegradable polymer devices can increase the therapeutic efficacy of drugs by producing high local tissue concentrations over extended periods of time. It has been shown previously that implantation of controlled-release polymers impregnated with the nitrosourea carmustine (BCNU) extended the period of survival in rats bearing the 9L glioma compared with similar rats treated with systemically administered BCNU. This study evaluated the effect on the monkey brain of interstitial delivery of BCNU by the biodegradable polyanhydride copolymer poly[bis(p-carboxyphenoxy)propane]anhydride (PCPP) and sebacic acid (SA) in a 20:80 formulation (PCPP:SA). ⋯ No neurological or general deleterious effects were seen in any of the animals. It is concluded that the interstitial delivery of BCNU by the polyanhydride polymer PCPP:SA is safe in the primate brain and that concomitant radiation therapy did not lead to any adverse effects. These experimental findings are important to an understanding of the clinical effects of PCPP:SA implants in treating brain diseases.
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Journal of neurosurgery · Jan 1994
Pathophysiology of syringomyelia associated with Chiari I malformation of the cerebellar tonsils. Implications for diagnosis and treatment.
The mechanisms previously proposed for the progression of syringomyelia associated with Chiari I malformation of the cerebellar tonsils are controversial, leave many clinical observations unexplained, and underlie the prevalence of different operations currently used as initial treatment. To explore the mechanism of syringomyelia progression in this setting, the authors used anatomical and dynamic (phase-contrast and phase-contrast cine) magnetic resonance (MR) imaging, and intraoperative ultrasonography to examine the anatomy and dynamics of movement of the cerebellar tonsils, the wall of the spinal cord surrounding the syrinx, and the movement of cerebrospinal fluid (CSF) and syrinx fluid at rest, during the respiratory and cardiac cycles, and during Valsalva maneuver in seven affected patients. In all patients the cerebellar tonsils occluded the subarachnoid space at the level of the foramen magnum. ⋯ Observations by the authors suggest the following previously unrecognized mechanism for progression of syringomyelia associated with occlusion of the subarachnoid space at the foramen magnum. The brain expands as it fills with blood during systole, imparting a systolic pressure wave to the intracranial CSF that is accommodated in normal subjects by sudden movement of CSF from the basal cisterns to the upper portion of the spinal canal. With obstruction to rapid movement of CSF at the foramen magnum, the cerebellar tonsils, which plug the subarachnoid space posteriorly, move downward with each systolic pulse, acting as a piston on the partially isolated spinal CSF and producing a systolic pressure wave in the spinal CSF that acts on the surface of the spinal cord.(ABSTRACT TRUNCATED AT 400 WORDS)
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Journal of neurosurgery · Jan 1994
Case ReportsRecurrence of ICA-PCoA aneurysms after neck clipping.
Between 1975 and 1992, 2211 patients underwent aneurysmal neck clipping at the Nara Medical University clinic and associated hospitals. The aneurysm in 931 of these patients was situated at the junction of the internal carotid artery (ICA) and posterior communicating artery (PCoA). Seven patients were readmitted 4 to 17 years after the first surgery because of regrowth and rupture of an ICA-PCoA aneurysmal sac that had arisen from the residual neck. ⋯ Type 2 includes aneurysms in which the proximal portion of a previous clip is situated at the corner of the ICA and aneurysmal neck and the distal portion on the enlarged dome of the aneurysm, because the sac is regrowing from a portion of the residual neck. In this type of aneurysm, a Sugita fenestrated clip can occlude the residual neck, overriding the old clip. Classifying these aneurysms into two groups is very useful from a surgical point of view because it is possible to apply a new clip without removing the old clip, which was found to be adherent to surrounding tissue.