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Biomedical subjects

J L Venes

Publications and source records attributed to J L Venes.

16 recordsLinked to original sources
PubMed1991

Intramedullary lesions of the pediatric spinal cord: correlation of findings from MR imaging, intraoperative sonography, surgery, and histologic study.

Findings of preoperative magnetic resonance (MR) imaging and radiologist-directed intraoperative sonography (IOS) were correlated with surgical and pathologic findings in 11 pediatric patients with intramedullary spinal cord lesions. There were seven gliomas and one each of primitive neuroectodermal tumor, venous vascular malformation, neuroenteric cyst, and active schistosomiasis. MR imaging provided discrete preoperative anatomic localization and excluded multicentric lesions but did not reliably distinguish between solid and cystic lesions. IOS helped (a) define the limits of intramedullary mass before the dura mater was opened and (b) differentiate cystic from solid components. The internal architecture of intramedullary lesions, as shown with MR imaging and sonography, was strikingly similar, allowing discrete correlative localization for biopsy or tissue resection. Gadolinium-enhanced MR imaging and IOS are complementary imaging techniques that should be used in concert for the evaluation and management of intramedullary lesions of the pediatric spinal cord. Both techniques display regions of cord abnormality, but neither definitively characterizes underlying tissue histology.

Adolescent↗
PubMed1979

Ventriculopleural shunting in the management of hydrocephalus.

6 cases of ventriculopleural shunting for control of hydrocephalus are presented. In the other child and adult, drainage of cerebrospinal fluid into the pleural cavity seems to be well tolerated in exceptional circumstances where other shunt procedures, including intracranial shunts, are contraindicated. In the infant and young child, accumulation of fluid in the pleural space is enchanced by a poorly understood immune-related mechanism and may lead to significant pulmonary dysfunction. On the basis of our experience, this procedure appears contraindicated in this age-group.

Adolescent↗
PubMed1979

B waves--a reflection of cardiorespiratory or cerebral nervous systems rhythm?

A review of 92 consecutive shunt revisions is presented in an attempt to assess the contribution of computerized axial tomography to the long-term management of the child with shunted hydrocephalus. 20-22 percent of all cases of acute shunt malfunction presented with small ventricles, indicating that absence of ventricular enlargement should not be interpreted as demonstrating adequate shunt function. The single most useful application of computerized axial tomography in our hands is the detection of indolent shunt malfunction associated with ventriculomegaly and decline of cognitive function in the older child.

Blood Pressure↗
PubMed1979

Loss of autoregulation and posttraumatic ischemia following experimental spinal cord trauma.

Blood flow in the dorsolateral funiculus of the cat thoracic spinal cord was studied after severe experimental cord injury, using a modification of the hydrogen clearance technique. Autoregulation was intact during the initial 60 to 90 minutes after cord injury, but was then lost coincident with the onset of ischemia. The data suggest that the ischemic response to spinal cord injury is mediated both by the loss of autoregulation and by relative vasoconstriction of the resistance vessels. Therapeutic intervention aimed at maintaining perfusion during the early posttraumatic period may prove of value in reversing or limiting some elements of dysfunction due to the secondary injury of ischemia.

Animals↗
PubMed1979

Alteration of posttraumatic ischemia in experimental spinal cord trauma by a central nervous system depressant.

Blood flow after severe experimental injury to the thoracic spinal cord was studied in cats, using a modification of the hydrogen clearance technique. Gamma hydroxybutyrate, a central nervous system depressant, was shown to markedly alter the ischemic response to injury if given during the early posttraumatic period. Other vasoactive drugs investigated had no effect on posttraumatic ischemia. Therapeutic intervention during the early posttraumatic period aimed at increasing blood flow while decreasing the metabolic requirements of the injured cord may prove of value in reversing or limiting some elements of long-tract dysfunction due to the secondary ischemic insult.

Animals↗
PubMed1979

Chemotherapy as an adjunct in the initial management of cerebellar medulloblastomas. A preliminary report.

Eight consecutive children with biopsy-proven cerebellar medulloblastoma were treated with a combination of whole neuraxis radiation and prolonged chemotherapy using vincristine and cyclophosphamide. There was no evidence of tumor recurrence in the follow-up period, which ranged from 16 months to 7 years and 8 months following diagnosis. Morbidity associated with this regimen has been infrequent and easily reversible.

Administration, Oral↗
PubMed1978

Management of severe cerebral edema in the metabolic encephalopathy of Reye-Johnson syndrome.

Fifteen critically ill children with the diagnosis of Reye-Johnson syndrome were treated with techniques developed to maintain adequate cerebral perfusion pressure and levels of circulating blood glucose. One child died, three sustained neurological deficit, and nine children (70%) recovered without significant neurological dysfunction. The technique developed during the period these children were treated, the indications for their use, and factors that can interfere with maintaining adequate cerebral perfusion in patients with increased intracranial pressure from metabolic encephalopathy are described. The results suggest that neurological damage in this syndrome results from neuronal injury secondary to inadequate cerebral perfusion and/or hypoglycemia, and that neurological dysfunction like hepatic dysfunction should produce minimal mortality and morbidity if cerebral perfusion and adequate levels of circulating blood glucose are sustained during the period of increased intracranial pressure and liver failure.

Adolescent↗
PubMed1978

Altered blood flow and secondary injury in experimental spinal cord trauma.

A modification of the hydrogen clearance technique was used to study blood flow in the dorsolateral funiculus of traumatized thoracic spinal cord in cats. The result of this study show that ischemia occurred in all animals both at the level of trauma, and 1 cm below the site of trauma. There was, however, a period of over 1 hour after trauma during which blood flow was maintained at both sites. This investigation not only confirms the presence of ischemia in the lateral funiculus of the injured spinal cord but suggests that a period of time exists in the posttraumatic period during which pharmacological intervention may alter the ischemic response and possibly prevent secondary injury resulting from the ischemia.

Animals↗
PubMed1977

Prolonged continuous monitoring of intracranial pressure in severe Reye's syndrome.

Evidence from both clinical and pathological investigations suggests that increased intracranial pressure (ICP) is a significant factor in the mortality of patients with Reye's syndrome. This, coupled with a critical review of our previous 22 patients, which failed to document the efficacy of exchange transfusion, led us to include continous ventricular pressure monitoring in the supportive care of children with Reye's syndrome. To date, three children, ages 3 to 5 years, have been managed with continuous ICP monitoring. All had stage IV coma by both clinical and electroencephalographic criteria. Peak blood ammonia concentrations were 1,036, 316, and 56micronug/100 ml; all had elevations of serum glutamic oxaloacetic transaminase level, prothrombin time, and creatine phosphokinase level as well. Rapid, unprediatble increases in ICP occurred for many days in all children. Therapeutic measures most successful in controlling ICP were the intravenous administration of mannitol and hyperventilation. Elevations in ICP occurred despite serum osmolality as high as 418 mOsm and following oral administration of glycerol. Rapid increases in ICP also resulted from routine manipulation of the patients (e.g., postural drainage). Exchange transfusion, used in two of the three patients, increased ICP in one child and had no effect in the other. All three children have achieved complete recovery and are doing well 6 months after their illness. Our experience with these children suggests that vigorous supportive therapy, including careful monitoring of ICP, should be used as a basis of comparison when evaluating claims of specific treatment in Reye's syndrome.

Ammonia↗
PubMed1976

Sagittal synostectomy. Technical note.

A procedure for correction of scaphocephaly is described. It differs from strip craniectomy in that it provides early correction of the deformity by removing the protuberances at the bregma and at the occiput. The morbidity and mortality of this procedure is no greater than with the more standard linear craniectomy.

Craniosynostoses↗
PubMed1976

Control of shunt infection. Report of 150 consecutive cases.

The author analyzes 150 consecutive ventriculovenous, ventriculoperitoneal, and lumboperitoneal shunt procedures with particular attention to shunt colonization by Staphylococcus epidermidis. There was one primary infection with Staphylococcus epidermidis early in the series, and in two other cases, the organism was felt to be a secondary invader. In those procedures involving either primary placement or revision of a ventriculovenous shunt, there was not a single infection. The operative protocol that has virtually eliminated Staphylococcus epidermidis is outlined.

Anti-Bacterial Agents↗
PubMed1975

Bifrontal decompressive craniectomy in the management of head trauma.

Retrospective analysis of 13 patients who had bifrontal decompressive craniectomy for the management of posttraumatic cerebral edema shows a significant decrease in expected mortality, but severe morbidity in the survivors. Only one patient returned to the pretrauma level of neurological function. No correlation could be found between the quality of survival and the neurological or operative findings. The need for more accurate prognostic criteria in the evaluation of severely head-injured patients is discussed.

Adolescent↗