Biomedical subjects
Publications and source records attributed to L N Sutton.
The authors report their development of a relatively inexpensive signal averager for evoked potentials based on an Apple home computer.
Medulloblastoma is the most common intracranial primitive neuroectodermal malignancy of childhood. Certain parameters are predictive of survival in children with medulloblastoma; however, tumor histology is of unclear prognostic value. A classification system, proposed by Rorke for all central nervous system (CNS) neoplasms composed of primitive neuroepithelial cells, was utilized in a review of 38 consecutive patients with newly diagnosed medulloblastoma. The classification is based on the concept that medulloblastoma is not unique to the cerebellum but is similar to tumors that may arise elsewhere in the CNS consequent to neoplastic transformation of primitive neuroepithelial cells. Cells forming the tumors may remain in the undifferentiated state or they may exhibit differentiation along glial, and/or ependymal, and/or neuronal lines. For purposes of simplification, the cases were divided into two major groups: those primitive neuroectodermal tumors (PNET's) which showed no evidence of cellular differentiation (PNET-U) and those that were differentiated (PNET-D). There were 20 cases in the PNET-U group and 18 in the PNET-D group. The 4-year survival rate was 70% for PNET-U, compared to 32% for PNET-D (p = 0.004). Only one of 10 children with PNET-D with differentiation along more than one cell line survived. Other factors, including age at diagnosis, tumor metastasis (TM) stage, and extent of surgical resection, were analyzed and were of prognostic importance; but histological features remained statistically significant within each subgroup.
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Eighty per cent of severe sports-related central nervous system trauma occurs as a result of collision sports, chiefly American football and rugby union football, followed by wrestling and gymnastics. Although serious head injury is uncommon, episodes of concussion are frequent; repeated concussion should be grounds for suggesting that the athlete give up collision sport. American and rugby union football are the sports mainly responsible for cervical spine injury with resultant quadriplegia.
The incidence, response to treatment, and outcome of children with pineal region neoplasms is poorly characterized. Since 1975, in one institution, 25 consecutive patients with pineal tumors have undergone biopsy prior to further treatment. This constituted 11% (25/234) of all brain neoplasms seen over this time period. Specific tumors diagnosed included pineal parenchymal tumors ( pineoblastomas , pineocytomas ) in eight patients (32%); germ cell tumors (embryonal cell carcinomas, teratomas, germinomas) in eight patients (32%); glial tumors (astrocytoma, ganglioglioma ) in eight patients (32%); and ganglioneuroblastoma in one patient (4%). Clinical parameters, computed tomographic findings and CSF markers (alphafetoprotein and human chorionic gonadotropin) were unreliable in discriminating between specific tumor types. Response to treatment and patterns of disease relapse were dependent on the type of tumor present. Five of eight children with pineal parenchymal tumors had disease recurrence, and in all leptomeningeal dissemination occurred prior to or concurrent with local relapse. Three of eight children with germ cell tumors and two of eight patients with glial tumors suffered a relapse; in all five children recurrence was initially local. Findings suggest that pineal region neoplasms are not infrequent in childhood; that these tumors vary greatly in histologic type; that contrary to other reports germinomas do not constitute the majority of pineal tumors; and that histologic confirmation is necessary prior to treatment for appropriate management.
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We have reviewed our experience with gangliogliomas treated in the post-computed tomography (CT) era at the Children's Hospital of Philadelphia. Of 234 newly histologically verified neoplasms seen at our institution since 1975, 10 (4.3%) were gangliogliomas of the cerebral hemispheres. The presenting complaint was seizures in 9 of 10 patients, and in 8 the seizures were poorly controlled despite increasing doses of anticonvulsant medication. At the time of diagnosis, only 2 patients had a focal neurological deficit and none had signs or symptoms of increased intracranial pressure. Learning disability and behavioral disturbances were common in this group of children. The CT appearance of these lesions was characteristic: most appeared as a cerebrospinal fluid density area that was located peripherally and often indented the skull. There was little contrast enhancement, and a few were diagnosed initially as arachnoid or porencephalic cysts. Despite the CT appearance, all but 2 of the lesions were found to be solid at operation. In one patient, the lesion appeared as an enhancing lesion of the thalamus, and this patient died. Operation resulted in symptomatic improvement. Eight of 9 children are alive, with a follow-up of 1 to 80 months (median, 19.5 months), and are free of progressive disease. Five are seizure-free while receiving anticonvulsant therapy and an additional 3 have improved seizure control as a result of operation. Two of the 3 children with intellectual difficulties preoperatively have shown improvement on testing after operation, probably the result of improved seizure control. One patient developed a disseminating malignancy and died. It is concluded that worsening seizures in the pediatric age group should warrant CT examination and that ganglioglioma should be included in the differential diagnosis of low density areas on CT.
Immunoreactive myelin basic protein (MBP) levels were measured in cerebrospinal fluid (CSF) samples taken from 57 patients with active hydrocephalus (age range 3 weeks to 60 years). Of these patients, 28 (49%) had elevated MBP values (greater than 4.5 ng/ml). Elevated MBP levels were found in 44% of patients with congenital hydrocephalus, 75% of patients with posttraumatic hydrocephalus, 80% of patients with normal-pressure hydrocephalus, and 83% of patients with porencephaly. Also associated with abnormal MBP levels was the ventricular size as measured by computerized tomography scanning (chi 2: p less than 0.05): 36% of the patients with small ventricles (ventricle:brain ratio 0 to 0.4:1) had elevated MBP in the CSF, whereas 61% of those with moderate ventricles (0.41 to 0.6:1 ratio) and 100% of those with large ventricles (0.61 to 0.85:1 ratio) had abnormal values. Only 33% of those with maximal hydrocephalus (0.86 to 1.0:1 ratio) had elevated MBP levels, perhaps because of dilution effects. In three patients in whom CSF was obtained simultaneously by ventricular and lumbar punctures, the ventricular fluid had a consistently higher concentration of MBP, suggesting a cerebral origin. It is concluded that active hydrocephalus produces significant periventricular demyelination, probably as the result of mechanical stretching.
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We retrospectively reviewed a process whereby parents were afforded additional time to decide the initial managements of their newborn with myelomeningocele. Of 110 newborn referrals, 52 (47%) had early surgery within the first 48 hours, 32 (29%) had delayed surgery between 3-7 days, 12 (11%) had late surgery from 7 days to 10 months, and 14 (13%) had no surgery, per parental request. There were no significant differences among the early, delayed or late surgery groups in mortality where 92%, 94% and 100% respectively were alive at 10 months, or the morbidity of worsening paralysis, ventriculitis or developmental delay. Our data suggest, therefore that there is no urgency or emergency for surgical intervention in the initial management of newborns with myelomeningocele. Rather, there is time to fully discuss issues with parents and obtain a better-informed consent for or against surgical management.
The authors report their investigation of the effects of high-dose barbiturates on the multimodality evoked response in 9 cats. After baseline evoked responses were obtained, boluses of pentobarbital were infused intravenously at regular intervals, amounting to cumulative total doses of 9, 18, 27, 45, 63, 123, and 183 mg/kg at respective infusions. This resulted in gradually increasing serum pentobarbital levels, reaching therapeutic coma levels (4 to 5 mg/dl) after the fifth infusion. At this point, the electroencephalogram was flat, and pressor agents were required to maintain cardiovascular stability. Evoked responses were obtained 15 minutes after each infusion. Brain-stem auditory evoked response (BAER) showed little change in wave latencies at therapeutic coma levels of pentobarbital. Further barbiturates resulted in delay of the late components of this response. In the somatosensory evoked responses (SER), early brain-stem components were relatively unaffected by therapeutic coma levels. Late brain-stem components and the initial cortical response showed progressive latency increase. Late cortical (association cortex) waves were abolished at relatively low doses. The central conduction time was relatively unaffected. The late waves of the visual evoked responses (VER) were abolished with low-dose barbiturates (9 mg/kg). A single positive-negative complex persisted despite massive infusions. It is concluded that evoked responses may prove useful in monitoring patients in deep barbiturate coma, but barbiturate effects must be kept in mind.
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The electrophysiological effects of cold-lesion edema and white-matter ischemia were studied in cats by reference to the short-latency somatosensory evoked response. The primary cortical waves were found to be considerably delayed following a period of white-matter ischemia; hosever, cold-lesion edema appeared to have no significant effect on the evoked response. The authors conclude that vasogenic edema does not interfere with axonal functioning by an ischemic mechanism.
The bioenergetic mechanisms of vasogenic edema were studied by measuring concentrations of adenosine triphosphate (ATP), phosphocreatine (CrP), and lactate in rapidly frozen edematous white matter in cats. When edema was produced using a cold lesion, it was found that both ATP and CrP were reduced to one-half of control values, and that lactate was elevated. When a correction was applied for dilution, however, it was found that high-energy phosphates were equal to control values, and that lactate was even more significantly elevated. This pattern contrasted with that seen in white-matter ischemia, in which CrP is depressed out of proportion to ATP. Finally, it was found that the white-matter lactate-concentration in the plasma infusion model of edema was increased. It is concluded that vasogenic edema induces an increase in lactate, but does not deplete high-energy phosphate compounds in affected white matter.
To define better the syndromes of hydranencephaly and maximal hydrocephalus, we followed 10 neonates demonstrating (by computerized tomography) virtual absence of the cerebral substance with serial computerized tomographic (CT) scans, electroencephalograms (EEGs), and developmental evaluations. The follow-up period ranged from 4 to 23 months. Two well-defined syndromes emerged. Five patients showed absence of cortical activity on EEG and a CT picture of minimal occipital brain parenchyma connected by a thin bridge of tissue to intact basal ganglia. These patients were shunted and showed no improvement with time, either neurologically or radiologically. Five patients showed minimal frontal cerebral mantle on CT and the presence of electrical activity on EEG. These patients required bilateral shunts to control head size and showed remarkable progress with time. Serial CT scans demonstrated the appearance of considerable brain substance, and neurological development was either normal or slightly delayed. We believe that the former pattern of only minimal occipital brain and absent EEG activity defines true hydranencephaly, whereas the presence of small amounts of frontal brain tissue associated with EEG activity seems to represent maximal hydrocephalus. The differences in CT pattern, EEG, and clinical progress all suggest a different pathophysiology for these two conditions. (Neurosurgery, 6: 35--38, 1980).
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The outcome in 53 children following severe head injury is presented. All children were graded using the Glasgow Coma Scale; 90% made a good recovery or were moderately disabled, and 8% died or were left vegetative. All patients were treated with controlled ventilation and steroids; mannitol, and, if necessary, Nembutal (pentobarbital) were used to maintain the intracranial pressure below 20 torr. With this regimen, only one death occurred due to uncontrollable intracranial hypertension. All patients with a coma scale of 5 or greater recovered well. The worst prognostic sign was the presence of flaccidity: 33% of these patients died or were vegetative. Five of seven patients who were decerebrate or flaccid with bilateral fixed pupils and absent caloric responses made a good recovery or were moderately disabled. The relatively low incidence of mass lesions (23%) and high incidence of diffuse cerebral swelling (34%) suggest a different pathophysiological response of the child's brain to injury, which may play a role in the improved survival of children following severe head injury when compared to adults.
OBJECTIVES: Despite advances in prenatal diagnosis, management of fetal myelomeningocele has been limited to abortion or supportive postnatal care. The rationale for fetal repair of myelomeningocele and initial clinical outcomes are discussed. METHODS: A complete review of the literature concerning fetal myelomeningocele and repair was performed. RESULTS: While myelomeningocele is a primary embryologic disorder, neurologic damage is also secondary to progressive in utero damage to the exposed spinal cord. Animal models with midgestational coverage of the spinal defect demonstrate near normal neurologic function at term. Early clinical results suggest that fetal closure can salvage neurologic function, reverse hindbrain herniation, and diminish the need for ventriculoperitoneal shunting. CONCLUSIONS: In utero repair of myelomeningocele may improve neurologic outcomes and reduce hindbrain herniation in selected patients.