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Biomedical subjects

M S Edwards

Publications and source records attributed to M S Edwards.

At least 217 records · Page 12Linked to original sources

Intracranial arachnoid cysts in children.

The clinical and radiographic findings, surgical treatment, and outcome in 16 pediatric patients with intracranial arachnoid cysts are reviewed. The clinical presentation reflected the anatomical location of the lesions. Computerized tomography or magnetic resonance imaging scans were diagnostic in all cases. Of the nine cysts treated primarily or secondarily by craniotomy for fenestration and drainage into the basilar cisterns, five recurred. Cyst-peritoneal shunting led to diminished cyst size and clinical improvement in all seven cases in which it was used as the initial treatment and in all four cases in which fenestration had been unsuccessful. The results in this series show that cyst-peritoneal shunting is the treatment of choice for most intracranial arachnoid cysts in children.

Adolescent↗

Spinal intramedullary spread of medulloblastoma. Case report.

The case of an 11-year-old boy is reported in whom two intramedullary lesions developed at the thoracic-cervical and thoracic-lumbar junctions 2 1/2 years after resection and irradiation of a medulloblastoma in the posterior fossa. There was no evidence of subarachnoid spread of the tumor. Magnetic resonance imaging was used to localize these lesions, and provided much better diagnostic information than either computerized tomography scans or myelograms.

Cerebellar Neoplasms↗

Cell kinetics analysis in a case of teratoma of the thoracic spine.

The authors report cell kinetics studies in an infant who had multiple operations for removal of a rare benign thoracic spinal teratoma with retroperitoneal extension. Before the final surgical procedure for recurrent tumor, bromodeoxyuridine (BUdR), 200 mg/sq m, was administered intravenously to label tumor cells in the S (deoxyribonucleic acid (DNA) synthesis) phase of the cell cycle. Histologically, the tumor was a mature teratoma consisting of components derived from all three germ-cell layers. Cells labeled with BUdR were found in the basal layer of stratified squamous epithelia, in respiratory epithelia, in the cartilage and surrounding perichondrial mesenchyme, and in loose mesenchymal tissue throughout the teratoma. In contrast to neuroectodermal tumors, which show widespread BUdR uptake throughout the tissue and which have different average labeling indices according to their histological type (range less than 1% to 15.2%), the teratoma showed BUdR labeling only in certain areas, indicating fairly organized growth patterns; the labeling indices in these areas ranged from 0.39% to 1.9%.

Bromodeoxyuridine↗

Development of multiple lesions during radiation therapy and chemotherapy in patients with gliomas.

To determine the percentage of patients who developed multiple central nervous system (CNS) gliomas during postoperative radiation therapy and chemotherapy, the authors reviewed the records of 1047 patients treated between December 2, 1976, and August 16, 1985, who had an original diagnosis of supratentorial glioblastoma multiforme or other anaplastic glioma. The occurrence of multiple lesions was verified by neurodiagnostic studies (computerized tomography or myelography) or by findings at operation or autopsy. Twelve patients (1.1%) who presented with multiple lesions were excluded from this analysis. There were 405 patients with glioblastoma multiforme; their median age was 46.5 years (range 22 to 70 years). Eighteen (5%) of these patients had multiple CNS lesions, five of which were in the spinal cord. The median time from diagnosis to detection of the second lesion in this group was 59.5 weeks (range 10 to 182 weeks). There were 630 patients with anaplastic glioma (which included mixed malignant glioma and highly anaplastic, gemistocytic, moderately anaplastic, and anaplastic astrocytomas); their median age was 30 years (range 2 to 62 years). Fifty-four (8.6%) of these patients had multiple lesions, 10 of which were in the spinal cord; only one case of extraneural metastasis was found. The median time from diagnosis to detection of the second lesion in this group was 101 weeks (range 14 to 459 weeks). These results show that more than 90% of CNS gliomas recur at the site of the original tumor. Considering the high frequency of intellectual dysfunction after whole-brain radiation therapy, the use of focal radiation fields appears to be the most judicious approach to the treatment of patients with gliomas.

Adult↗

An evaluation of the in utero neurosurgical treatment of ventriculomegaly.

Clinical results for in utero treatment of ventriculomegaly are not impressive; results may improve, however, with new techniques and more experience. Nonetheless, even in the best of hands, it is not always possible to identify associated and sometimes fatal congenital abnormalities on high resolution obstetric ultrasonograms, and not enough is known of the natural history of CNS congenital disease, in particular of ventriculomegaly, to select the appropriate fetus for in utero treatment. Results of animal studies are encouraging, but more work is needed to define the pathophysiology, knowledge of which might allow selection of the appropriate fetus and treatment modality.

Animals↗

Tumor markers and cytologic features of cerebrospinal fluid.

Tumor markers are useful in establishing the diagnosis of certain central nervous system tumors, especially germinal tumors of the pineal region. They are not sufficiently specific to be able to replace biopsy for exact diagnosis. They may also be useful for monitoring of therapy, as an indicator of recurrence of the tumor. Cerebrospinal fluid cytology is not generally useful in establishing a specific histologic diagnosis, especially in children, but can help to monitor therapy and predict tumor recurrence. More extensive studies are needed in both areas to define more precisely the role of markers and cytologic studies.

Brain Neoplasms↗

Staging of cerebral hemispheric tumors.

There is currently no adequate staging system for cerebral astrocytomas. A scheme for acquiring data that can be used to stage cerebral hemisphere tumors is suggested. This data base, in conjunction with treatment and survival information, may be useful in the management of childhood hemispheric tumors.

Brain Neoplasms↗

Systemic staging of supratentorial extra-axial brain tumors in children. Craniopharyngiomas, atypical teratoma and teratoid tumors of the suprasellar region (germinomas), and intracranial teratomas.

A staging system has been proposed for the following tumors: craniopharyngiomas, germinomas, and intracranial teratomas. Various aspects of the specific pathologic and growth characteristics of the tumor determines such categorization and subclassification of the tumors. A brief analysis of the clinical aspects in reference to classification is presented. The suggested systems will need to be tested in clinical studies to determine their validity.

Brain Neoplasms↗

Evaluation of SR-2508 induced neurotoxicity and myotoxicity in rats using brainstem auditory evoked potentials and the posterior auricular muscle response.

Brainstem auditory evoked potential (BAEPs) and a middle latency component attributed to the posterior auricular muscle response (PAMR) to an intense auditory stimulus were used to measure the onset of neurotoxic and myotoxic effects in rats after chronic exposure to the radiosensitizer SR-2508. The rats received intraperitoneal injections of SR-2508, 500 mg/kg, 5 days/week for 6 weeks. BAEP and PAMR were measured after 10, 20, and 30 injections and 4 weeks after the drug treatment was stopped. A significant neurotoxic effect was observed: After 10 injections of SR-2508, latency of the fourth positive (P4) component of the BAEP, which is thought to represent activity from the superior olivary nuclei, increased from baseline levels, and a further increase was measured after 30 injections. Four weeks after drug treatment was stopped, P4 latency had not returned to baseline levels, indicating permanent injury. PAMR latency was also increased after 10 injections of SR-2508, but increased no further during the drug treatment period. Four weeks after the last injection, PAMR latencies had returned to pretreatment levels, indicating that the myotoxic effects of SR-2508 were reversible.

Animals↗

Long-term sequelae of group B streptococcal meningitis in infants.

The long-term outcome and admission features predictive of outcome were determined for 61 patients with group B streptococcal meningitis treated between 1974 and 1979. Infection was rapidly fatal in 13 patients (21%). Among the 48 survivors, 38 (79%) 3 years of age or older were available for comprehensive evaluation. Excluding five who had died before age 3 years, the mean age at evaluation was 6.0 years (range 3.3 to 9.0 years). Among survivors, 11 (29%) had severe neurologic sequelae, eight (21%) had mild to moderate deficits, and 19 (50%) were functioning normally. Analysis of predictive features revealed a significant risk of death or severe impairment among infants who at hospital admission were comatose or semicomatose, had decreased perfusion, total peripheral WBC less than 5,000/mm3, absolute neutrophil count less than 1000/mm3, and CSF protein greater than 300 mg/dl (P less than or equal to 0.05). These data indicate that, although mortality from group B streptococcal meningitis has declined, approximately half of the survivors of acute infection have some degree of morbidity when evaluated at ages permitting the detection of language delay and borderline or mild mental retardation.

Cognition Disorders↗

Immune globulin for intravenous use: enhancement of in vitro opsonophagocytic activity of neonatal serum.

Neonates born with less-than-protective levels of transplacentally derived specific antibody are at risk for the development of disease due to type III, group B Streptococcus (III-GBS). The effect of immune serum globulin modified for intravenous use (MISG) on in vitro opsonophagocytosis of III-GBS was evaluated. Cord blood was obtained from 13 healthy, full-term neonates, and bactericidal activity for III-GBS was measured. Before the addition of MISG, one of three serum specimens with moderate levels of antibody to III-GBS, and eight of 10 specimens with low antibody levels demonstrated no bactericidal activity. The mean bactericidal index increased from 27.1% before the addition of MISG to 96.5% with MISG added in a volume equal to that of serum. The effect of MISG on opsonophagocytosis decreased with its dilution in buffer, and no effect was shown at dilutions greater than or equal to 1:4. Thus, MISG can substantially increase in vitro opsonophagocytosis of III-GBS in sera from newborns.

Antibodies, Bacterial↗

Single-dose pharmacokinetics of imipenem-cilastatin in neonates.

The single-dose pharmacokinetics of imipenem (N-formimidoyl thienamycin), a beta-lactam antibiotic, used in combination with cilastatin, a renal dehydropeptidase I inhibitor, were evaluated in 10 neonates 1 to 8 days of age. The imipenem-cilastatin combination was given intravenously over a 15-min period at a dose of 15 or 25 mg/kg. Drug concentrations in serum, urine, and cerebrospinal fluid (when available) were determined by high-pressure liquid chromatography, and plasma disposition of the drugs was described by a two-compartment open model. The mean peak plasma levels of imipenem 30 min postinfusion were 55.4 and 27.2 micrograms/ml, and the mean t1/2 beta values were 2.1 and 1.8 h at doses of 25 and 15 mg/kg, respectively. The calculated volume of distribution was 0.41 liters/kg. In two patients from whom cerebrospinal fluid was obtained 1.5 h postinfusion, imipenem levels were 5.6 and 1.1 micrograms/ml at doses of 25 and 15 mg/kg, respectively, representing 10 and 4% of the 1-h serum levels. No side effects attributable to a single dose of imipenem-cilastatin were noted.

Chromatography, High Pressure Liquid↗

Hemangiomatous anomaly of bone in Crouzon's syndrome: case report.

A striking and diffuse hemangiomatous architecture was identified by microscopic examination of bone specimens obtained at cranial synostectomy and from the craniofacial area of a young boy with Kleeblättschadel deformity and Crouzon's syndrome. A retrospective review of the histopathological appearance of bone specimens from other patients with Crouzon's syndrome treated on our service and a review of the literature on craniosynostosis suggest that the hemangiomatous pattern seen in this patient is rare if not unique. The unusual pathological findings provide evidence that the underlying pathophysiology of this disorder may be heterogeneous.

Abnormalities, Multiple↗

An unusual spinal meningioma in a child: case report.

Meningiomas seldom occur in children, and spinal meningioma in a child is rare. We report the case of a boy, 3 years and 5 months of age, who had an unusual atypical meningioma involving the subarachnoid space from T-2 to the cauda equina. To our knowledge, no similar case has been reported previously.

Child, Preschool↗

Outcome from severe head injury in children and adolescents.

A consecutive series of 37 children (17 years old and under) with severe head injury is presented. The data confirm that morbidity and mortality are lower in children than in adults: 51% of these young patients had a good recovery or moderate disability at 6 months. The mortality rate in this series (33%) is higher than in some reports, but probably more closely approximates the death rate from these injuries in an unselected pediatric population than do statistics from tertiary care hospitals. There was no significant relationship between age and outcome in this age group, but mass lesions and uncontrolled intracranial hypertension adversely affected outcome. Diffuse cerebral swelling was commonly seen on computerized tomography scans, and generally was associated with a satisfactory outcome (75%). Two of 13 deaths were considered preventable, emphasizing the narrow therapeutic safety margin and extreme care required in treating these patients.

Adolescent↗

Postirradiation cerebellar glioma. Case report.

A 13-year-old girl developed an anaplastic astrocytoma of the cerebellum 7 years after irradiation of the central nervous system and prophylactic chemotherapy for acute lymphocytic leukemia. The fact that the astrocytoma was anaplastic and infiltrative was unusual for astroglial tumors at this site. It is proposed that this is a radiation-induced glioma.

Adolescent↗

Effect of hematoporphyrin derivative photoradiation therapy on survival in the rat 9L gliosarcoma brain-tumor model.

Intracerebral tumors were produced in 99 rats by stereotaxic implantation of 9L gliosarcoma brain-tumor cells. Hematoporphyrin derivative (HPD), 10 or 20 mg/kg, was administered as an intravenous bolus 24 or 48 hours before irradiation of the tumor region with light from an argon pumped-dye laser (632 nm). Laser light, at a dose of 30, 60, or 200 joules/sq cm, was delivered through a craniectomy 10 or 13 days after tumor implantation. Survival times were significantly prolonged in rats exposed to laser light at a dose of 200 joules/sq cm 24 hours after administration of HPD, 20 mg/kg.

Animals↗