Panventricular enlargement often follows intraventricular hemorrhage in the premature neonate. During a recent 12-month period, the authors identified five infants who required shunting because of symptomatic post-hemorrhagic hydrocephalus, which was progressive despite serial lumbar punctures and the use of indwelling subcutaneous ventricular reservoirs. In the first 6 months following placement of the initial shunt, four of the infants required an additional shunt for isolated ventricles. Two children had isolation of the lateral ventricles and required bilateral shunts. Two other children had isolation of the fourth ventricle from the lateral ventricular system and required posterior fossa shunts. All of the children were treated successfully using multiple shunts. In all cases, progressive dilation of the isolated ventricle was unaccompanied by the usual clinical signs of shunt malfunction. It appears that isolated ventricular systems are common following post-hemorrhagic hydrocephalus and these children must be followed closely with ultrasound and computerized tomography scanning.

✓ A case of congenital tethered cervical spinal cord is presented in a young adult. Metrizamide computerized tomography was the most useful imaging technique for identifying the tethered spinal cord. Intraoperative somatosensory evoked potentials correlated well with clinical improvement following surgery.

HRP was injected by pressure from glass capillary micropipettes unilaterally into the lateral nucleus of rat so as to encompass the entire nucleus, but without spread into the interpositus nuclei. The cells of origin of the afferents to the lateral nucleus were studied after retrograde transport of the HRP. The reticulotegmental nucleus of the pons was labelled bilaterally and is the major source of crossed and uncrossed reticular imputs. The pontine nuclei also provide extensive crossed and uncrossed afferents. The inferior olive gives a large crossed olivo-lateral nucleus projection and a minor uncrossed input. The trigeminal nuclear complex--the nucleus of the spinal tract and the mesencephalic, principal sensory, and motor nuclei--all provide uncrossed afferents. The rostral portion of the lateral reticular nucleus gives a small crossed and uncrossed projection while the perihypoglossal nuclei and the dorsal parabrachial body give crossed afferents to the lateral nucleus. The norepinephrine afferent system from the locus coeruleus is represented by one or two heavily labelled cells and the serotonin raphe systems come from at least five raphe subgroups, the dorsal, superior centralis, pontis, obscurus and magnus nuclei. No evidence was found for commissural fibers between ipsilateral or contralateral cerebellar nuclei, or afferent axons from the spinocerebellar nuclei and the paramedian retricular nucleus. The significance of these sources of afferent imputs to the lateral cerebellar nucleus is discussed. The question is raised of the direct relationship between size of terminal axonal arborization and the quantity of HRP granules present in a cell retrograde transport. The limitations of the HRP method for detecting subtle local differences in the distribution of afferents within the heterogeneous groups of neurons in the lateral nucleus are discussed.

We evaluated 15 consecutive patients with malignant astrocytomas who were reoperated for functional status and survival. Their Karnovsky Performance Status (KPS) was not changed by surgery. None suffered perioperative death, wound infection, or complications. Patients with glioblastoma maintained KPS unchanged for a mean of 13 weeks (median, 10 weeks); with anaplastic astrocytoma, mean, 37.2 weeks (median, 24 weeks). Life spans were approximately twice that of non-reoperated historical controls. Reoperation for patients with recurrent malignant astrocytoma should be seriously considered when a gross total re-resection can be the goal in a patient whose tumor is in an accessible brain region.