The production of cerebrospinal fluid and the transport of (24)Na from the blood to the cerebrospinal fluid were studied simultaneously in normal and choroid plexectomized rhesus monkeys. Choroid plexectomy reduced the production of cerebrospinal fluid by an average of 33 to 40 percent and the rate of appearance of (24)Na in the cerebrospinal fluid and its final concentration were proportionately reduced. In both normal and plexectomized animals, (24)Na levels were found to be markedly greater in the gray matter surrounding the ventricles and in the gray matter bordering the subarachnoid space. That sodium exchanges in these two general areas of the brain may be linked to the formation of the cerebrospinal fluid is discussed here.
The effect of naltrexone (0.5, 1.0, 1.5, and 2.0 mg/kg) on the frequency of self-injurious behavior (SIB) was investigated in three male adolescents. The frequency of total SIB was reduced significantly in all three subjects; dose-dependent decreases (at 0.5, 1.0, and 1.5 mg/kg) in SIB frequency were observed in the two mentally retarded subjects. These data suggest a role for opioid peptides in SIB.
The descent of radiopharmaceuticals injected within the right lateral ventricle toward and into the spinal subarachnoidal spaces has been followed by scintiphotographic techniques and by computerized flow analysis in a group of "normal" patients. A substantial and rapid downward progression of the albumin-tagged tracer has been observed. This progression is faster than the subarachnoidal ascent toward the convexity of the brain.
A ventricular perfusion technique was used to determine the rate of cerebrospinal fluid (CSF) formation in a 5-year-old child who had undergone bilateral choroid plexectomy for communicating hydrocephalus during infancy. At the time of the study, the patient had a failed ventriculoperitoneal shunt and was suffering from progressive ventriculomegaly. The calculated rate of CSF formation, 0.35 ml/min +/- 0.02 standard deviation, was within normal limits.
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