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Biomedical subjects

R W Seiler

Publications and source records attributed to R W Seiler.

13 recordsLinked to original sources
PubMed1990

Early prognosis of supratentorial grade 2 astrocytomas in adult patients after resection or stereotactic biopsy. An analysis of 50 cases operated on between 1984 and 1988.

50 adult supratentorial low-grade astrocytomas operated upon between 1984 and 1988 were analysed retrospectively with respect to postoperative condition and progression-free survival. Pilocytic lesions were excluded. In 32 instances the tumour was macroscopically completely removed and partially in 4. In 14 cases a stereotactic biopsy was performed only. 10 patients received postoperative radiotherapy with 55 to 65 Gy. 1 patient died perioperatively from pulmonary embolism. 39 patients could resume their previous activities after discharge from the hospital, 10 were significantly disabled by neurological deficit, reduced neuropsychological performance or medically intractable epilepsy. Postoperatively, most patients required continuous anti-epileptic medication, 10 recurrences or tumour progressions of incompletely removed or merely biopsied lesions were observed within the mean follow-up period of 22 months. All recurrences after gross total removal, that were reoperated, had progressed to a malignant glioma. Of the prognostic tumour characteristics analysed, a histologically well-delineated tumour demarcation was most clearly associated with a favourable prognosis. Concerning treatment modalities, gross total resection was associated with a favourable prognosis. Radiotherapy was associated with an unfavourable outcome but this is probably due to selection of otherwise unfavourable cases.

Adolescent↗
PubMed1990

Evaluation of posttraumatic cerebral blood flow velocities by transcranial Doppler ultrasonography.

Thirty-five patients were admitted to the hospital with Glasgow coma scale scores of 4 to 7 after severe, blunt head injury. Blood flow velocities of the middle cerebral artery (MCA) and the ipsilateral internal carotid artery (ICA), high in the neck, were recorded noninvasively by Doppler ultrasonography. Serial examinations were begun within 48 hours of trauma and continued until the patient either died or was discharged. Spasm of the MCA was assumed if the ratio of the velocity of blood flow in the MCA (VMCA) to the velocity of blood flow in the ICA (VICA) exceeded 3 (normal value, 1.7 +/- 0.4). In cases of severe MCA spasm, this ratio is higher because of increased flow velocity in the MCA and reduced flow in the ICA due to increased cerebrovascular resistance. Higher MCA velocities with VMCA/VICA above 3, consistent with MCA spasm, were found in 14 of the 35 patients (40%). The increase began as early as 48 hours after injury, reached a maximum between Days 5 and 7, and lasted until 2 weeks after injury. There was a significant correlation between the occurrence of vasospasm and the quantity of cisternal or intracerebral blood seen on a computed tomographic scan. No correlation was found with the age of the patients, the Glasgow coma scale score at admission, the intracranial pressure, or the functional outcome 6 months after injury. The occurrence of a secondary infarction in a patient with severe MCA spasm suggests that, at least in some cases, spasm may influence the prognosis.

Adolescent↗
PubMed1990

Effect of nimodipine on cerebrovascular response to CO2 in asymptomatic individuals and patients with subarachnoid hemorrhage: a transcranial Doppler ultrasound study.

The cerebrovascular response to CO2 was evaluated by measuring relative changes in blood flow velocity within the middle cerebral artery by transcranial Doppler ultrasonography during normo-, hypo-, and hypercapnia. In seven patients without subarachnoid hemorrhage (five with unruptured arteriovenous malformations and two with aneurysms), the CO2 vasoreactivity was tested on the side of the middle cerebral artery with normal flow velocities opposite the lesion. A baseline CO2 reactivity test was obtained in each patient and then repeated under constant intravenous infusion of nimodipine, 2 mg/hr. Nine patients with ruptured aneurysms who were rated at Hunt and Hess Grades 1 or 2 were operated on within 1 to 3 days after the hemorrhage and treated with nimodipine, 2 mg/hr, given intravenously. In these patients, CO2 vasoreactivity was tested during the second week after the hemorrhage, when the middle cerebral artery velocity was increased by at least 50% of the initial value or more. Nimodipine was then discontinued and, 48 hours later, when the middle cerebral artery velocity was still in the same range, CO2 vasoreactivity was tested again. Two months later, after full recovery from the subarachnoid hemorrhage and normalization of the velocities, a third measurement of CO2 reactivity was obtained as a baseline control. No significant effect of nimodipine on CO2 vasoreactivity could be demonstrated in any of the test periods. In the second week after a subarachnoid hemorrhage, a significant reduction of the cerebrovascular response to CO2 was found (P less than 0.005).

Adolescent↗
PubMed1990

[Stereotaxic brain puncture. Indications and results].

228 stereotactic biopsies for the diagnosis of brain lesions were evaluated. In 98.2% a diagnosis could be established. The diagnosis was made of brain tumor in 79.3%, of brain abscess in 7.5% and of encephalitis in 3.5% of cases. In 2.2% of the patients a pathological finding was obtained without a clear histological definition. No histological diagnosis could be made in 1.8% of the patients. A severe complication of brain biopsy occurred in 2.2% of the patients (1 death, 1 abscess, 3 increased impairments). The stereotactic procedure appears to have a low mortality and morbidity, and to be highly accurate.

AIDS Dementia Complex↗
PubMed1979

Preoperative radiotherapy and chemotherapy in hypervascular, high-grade supratentorial astrocytomas.

From a group of ten patients with hypervascular, high-grade, supratentorial astrocytomas, five were treated with pre-operative radiotherapy alone, and five with radiotherapy in combination with cytostatic drugs. The aim was to investigate the timing of intracranial operations in the multimodality therapy of brain tumors. The tumor size was diminished only in one case, but tumor vascularization was reduced in half of the cases by the pre-operative treatment. Survival was not improved. Surgical treatment still should be the first of the therapeutic measures. Pre-operative radiotherapy may be of value to reduce tumor vascularization in hypervascular, centrally localized tumors.

Adult↗
PubMed1979

Delayed response to brain tumor chemotherapy.

Five cases of recurrent malignant gliomas are reported. They showed unequivocal and long-lasting improvement of the clinical status and brain scintigram after progressive clinical and scintigraphic deterioration occurred during the initial courses of chemotherapy. The differential diagnosis of tumor regrowth and this unusual delayed response are discussed. Swelling of dead tumor cells and a secondary inflammatory reaction could explain the initial clinical deterioration. The delayed response may be consistent with the slow removal of dead cells from the brain. This has been observed experimentally. Evaluation of the response of a malignant glioma to chemotherapy should be made by serial observations during a sufficiently long period of time.

Adult↗
PubMed1979

Primary intraventricular oligodendrogliomas.

Two cases of primary intraventricular oligodendrogliomas which were successfully removed by a transventricular approach using microtechniques are presented. Oligodendrogliomas in this location are very rare. The literature is reviewed.

Adolescent↗
PubMed1979

Combination chemotherapy with VM 26 and CCNU in primary malignant brain tumors.

Twenty-seven patients with inoperable or recurrent primary malignant brain tumors after previous resection and/or radiotherapy, were treated with corticosteroids and a combination chemotherapy consisting of VM 26 and CCNU. There were 15 (55%) patients that responded, three with a complete and 12 with a partial response with a mean duration of response of 13.4 months. Toxicity was mainly hematological and of acceptable degree. Combination chemotherapy with VM 26 and CCNU is well tolerated and can be administered on an out-patient basis. In our experience it is better than single agent chemotherapy.

Adolescent↗
PubMed1978

Supratentorial haemangioblastoma. Case report.

A case of supratentorial haemangioblastoma is presented. Diagnostic examinations, including computerized axial tomography, were not accurate. Histological examination of the removed tissue disclosed the correct diagnosis. Supratentorial haemangioblastomas are very rare tumours. We describe a case with regard to preoperative neuroradiological investigations, computerized axial tomography, and final histological diagnosis.

Adult↗
PubMed1978

Radiotherapy combined with procarbazine, bleomycin, and CCNU in the treatment of high-grade supratentorial astrocytomas.

Twenty consecutive patients with supratentorial Grade III and IV astrocytomas were treated with postoperative radiotherapy, and a simultaneous induction chemotherapy with 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU), procarbazine, bleomycin, and maintenance chemotherapy with CCNU. They were compared to 32 retrospective control patients selected similarly, who had received postoperative radiation therapy alone. The median survival time was 56 weeks for the combined treatment group, and 51 weeks for the control group. There was no statistical difference in survival in the two groups of patients.

Adolescent↗
PubMed1978

Adjuvant chemotherapy with intraventricular methotrexate and CCNU after surgery and radiotherapy of medulloblastomas.

Seven patients were treated with a combination of intraventricular methotrexate (MTX) and oral CCNU after resection and whole CNS irradiation of medulloblastomas. 3 patients survived 3 or more years after the operation which is not different from reported series with postoperative radiotherapy only. Adjuvant chemotherapy is experimental and should be employed only in controlled studies. The inadequate bone marrow reserve after previous spinal irradiation is a major problem. Because of its delayed and unpredictable myelotoxicity, CCNU is in our experience not a suitable substance for adjuvant combination chemotherapy of medulloblastomas. No complication was observed with 81 intraventricular injections of MTX. It is a good agent and deserves further clinical trials in less myelotoxic combinations.

Brain Neoplasms↗