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Biomedical subjects

R I Ernestus

Publications and source records attributed to R I Ernestus.

At least 37 records · Page 2Linked to original sources
PubMed1997

Chronic subdural hematoma: surgical treatment and outcome in 104 patients.

BACKGROUND: The common occurrence of chronic subdural hematoma (CSDH) in older patients raises some diagnostic and therapeutic difficulties. Despite general agreement about the indication of operation, the extent of surgery is still discussed controversially. We have, therefore, reviewed operative findings and outcome in 104 patients with CSDH. METHODS: Retrospective analysis was performed by differentiating age < or = 60 years (n = 28) versus age > 60 years (n = 76) and burr hole craniostomy with a size range from 12-30 mm (n = 94) versus larger craniotomy (n = 10). All patients received closed-system drainage of the subdural space for 2-4 days. RESULTS: Four patients older than 60 years died within 30 days after surgery, two in each operative group. Excluding these postoperative deaths, 17 out of 92 patients (18.5%) after burr hole trepanation and one out of eight patients (12.5%) after craniotomy required reoperation due to rebleeding (n = 6), residual subdural fluid (n = 4), and residual thick hematoma membranes (n = 8). Eight patients, who had been initially treated by burr hole craniostomy despite preoperative detection of neomembranes by contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), recovered without further intervention. Clinical outcome was good in both operative groups. The percentage of patients without or with only mild neurologic deficits at the time of discharge from the hospital was 72.3% in the burr hole and 70.0% in the craniotomy group, respectively. CONCLUSIONS: The clinical data of the present study suggest that burr hole craniostomy with closed-system drainage should be the method of choice for the initial treatment of CSDH, even in cases with preoperative detection of neomembranes. Craniotomy should be carried out only in patients with reaccumulating hematoma or residual hematoma membranes, which prevent reexpansion of the brain.

Adult↗
PubMed1997

The clinical and prognostic relevance of grading in intracranial ependymomas.

The clinical relevance of grading in ependymomas is almost always regarded as controversial. According to the classification of brain tumours revised by the World Health Organization (WHO) in 1993, brain tumours of ependymal origin are differentiated as subependymomas Grade I, ependymomas Grade II, and anaplastic (malignant) ependymomas Grade III. The purpose of the present retrospective study of 126 patients with intracranial ependymomas was to assess the clinical and prognostic significance of the topical classification and grading system by a uni- and multivariate statistical analysis. 87 Grade II ependymomas were predominantly located in the midline and in the fourth ventricle, whereas 39 anaplastic ependymomas Grade III were most often found in the cerebral hemispheres. Excluding the localization-linked operative mortality, progression-free survival (PFS) was significantly dependent on the histological grading. Median PFS time was 7.5 years in Grade II, but only 1.5 years in Grade III ependymomas. Stratifying for the two time intervals 1951-1970 and 1971-1990, and excluding the operative mortality, a multivariate Cox' model analysis of the covariates age, localization, grading, extent of surgery, and radiation therapy revealed that only the histological grading and radiation therapy had a significant impact on PFS. Thus, the WHO grading system has a statistically significant relevance for the long-term prognosis of intracranial ependymomas. However, the therapeutic management including radical tumour resection and additional local irradiation should be independent of the grading.

Adolescent↗
PubMed1997

CT and MR imaging in primary cerebral non-Hodgkin's lymphoma.

PURPOSE: To determine the morphological appearance and topographical distribution of primary cerebral non-Hodgkin's lymphoma (NHL). MATERIAL AND METHODS: CT and MR examinations of 68 patients with primary cerebral NHL were analyzed. The NHLs were classified by the Kiel classification and immunohistological data, as centroblastic (25), immunoblastic (24), lymphoblastic (5), Burkitt (1), non-subclassifiable type B (11), and T-cell lymphoma (2). RESULTS: Centroblastic lymphomas tended to predominate in the parietal lobe (56.5%) and the corpus callosum (59.1%) while immunoblastic lymphomas were mainly distributed in the frontal lobe (52.8%). About 2/3 of all NHLs showed a multifocal occurrence. Important for differential diagnosis, ventricular involvement was proved in 83.3% of these cases. In the remaining 26 patients with a solitary lymphoma, a periventricular location could be detected in only 8 cases. Central necroses were frequent in HIV-positive patients (7/11, 63.6%) but rare in the HIV-negative patients (9/57, 15.8%). On T2-weighted SE MR images, 8/11 centroblastic lymphomas gave a signal that was isointense with, or lower than, that of the contralateral white matter, while 8/10 immunoblastic lymphomas gave a higher signal. CONCLUSION: The radiological finding of multifocal brain lesions with ventricular involvement is relatively specific for primary cerebral NHL. However, subclassification on the basis of the CT or MR imaging results is not yet possible.

Adult↗
PubMed1997

Nontraumatic subarachnoid hemorrhage: value of repeat angiography.

PURPOSE: To evaluate the benefits and risks of repeat cerebral angiography in patients with subarachnoid hemorrhage of unknown cause. MATERIALS AND METHODS: Findings from 391 angiographic examinations (323 initial, 68 repeat) were retrospectively reviewed in 323 patients with nontraumatic subarachnoid hemorrhage to determine the cause of bleeding and the frequency of complications with neurologic deficit. RESULTS: At the initial angiographic examination, aneurysms were found in 195 patients (60.4%), and arteriovenous malformations were found in 11 patients (3.4%). Sixty-six patients with negative findings at initial examination underwent repeat cerebral angiography. Three additional aneurysms were detected, all of which could be seen retrospectively on the initial angiogram. In 63 patients, the cause of bleeding remained unexplained. Complications of the 391 angiographic examinations were definitive neurologic deficits in one patient (0.2%) and transient deficits in seven patients (1.8%). CONCLUSION: Repeat angiography is not necessary in patients with subarachnoid hemorrhage if technically good, carefully evaluated digital subtraction angiography was performed initially. Repeat angiography seems to be justified only when the initial examination is technically inadequate, when vasospasm is present, or if further bleeding occurs.

Adolescent↗
PubMed1996

Polyamine metabolism in gliomas.

Biosynthesis of the polyamines putrescine, spermidine, and spermine has been found to be activated in tissues with cellular proliferation. In the present study we have investigated polyamine levels and the activity of the first rate-limiting enzyme ornithine decarboxylase (ODC) in tumour samples obtained during operation of 202 patients with gliomas. Biochemical data were closely related to the grading of malignancy and to the morphological characteristics of each sample. Mean ODC activity was significantly higher in all gliomas as compared to peritumoural non-neoplastic brain. Furthermore, it was significantly higher (p < or = 0.001) in anaplastic gliomas who grade III and IV (9.0 +/- 9.6 nmol/g/h) than in gliomas WHO grade I and II (3.3 +/- 4.2 nmol/g/h). Highest enzyme activity (58.5 nmol/g/h) was found in solid and vital parts of malignant tumours, whereas predominantly necrotic areas exhibited low ODC activity (< 1 nmol/g/h). Thus, intra- and interindividual variability of ODC activity corresponded well to histomorphological heterogeneity in high-grade gliomas. Putrescine levels also increased with rising grade of malignancy, whereas spermidine and spermine levels did not correlate with the histological grading. In conclusion, high ODC activity represents a biochemical marker of malignancy in gliomas, but low values do not prove benignity. The present study reinforces the need of further and more extensive tumour sampling closely related to follow-up investigations in the heterogeneous group of gliomas.

Adolescent↗
PubMed1996

Prognostic relevance of localization and grading in intracranial ependymomas of childhood.

Intracranial ependymomas represent one of the most frequent brain tumors in childhood. Their preferred midline localization and their often controversially discussed classification prompted the present study of 67 intracranial ependymomas in children less than 15 years of age who were operated on from 1951 to 1990. Clinical data and follow-up of all children were retrospectively analyzed by calculation and statistical comparison of progression-free survival (PFS). According to the WHO classification as revised in 1993, 1 grade I subependymoma, 38 grade II ependymomas, and 28 grade III anaplastic (malignant) ependymomas were differentiated. Grade II ependymomas were predominantly located in the IV ventricle and in the supratentorial midline, which often made complete tumor resection impossible. In contrast, the majority of grade III tumors, most often situated in the cerebral hemispheres, could be totally removed. Operative mortality was higher in grade II than in grade III tumors. After recovery from operation, PFS was mainly determined by the histological grading. Median postoperative PFS was 120 months in grade II, but only 18 months in grade III ependymomas (P = 0.1417). Thus, despite varying therapeutic concepts, analysis of this 40-year collective study confirms the prognostic relevance of localization and WHO grading in the case of intracranial ependymoma in children.

Adolescent↗
PubMed1996

Lesions of the corpus callosum in hydrocephalic patients with ventricular drainage--a CT-study.

Patients with ventricular drainage may develop lesions of the corpus callosum. In order to study frequency, pathogenesis and clinical relevance of callosal lesions, 301 routine CT investigations of 79 patients with ventricular drainage were reviewed. Hypodense lesions in the anterior part of the corpus callosum were observed in 7 patients with longstanding hydrocephalus of variable origin, in 2 cases the corpus callosum was slightly swollen. All 7 patients showed signs of forced ventricular drainage. The callosal alterations were clinically inapparent and potentially reversible. Knowledge of these lesions is important to avoid misinterpretation.

Adolescent↗
PubMed1996

[Legal definition of the accident concept in social accident insurance].

For the first time, the "Gesetz zur Einordnung des Rechts der gesetzlichen Unfallversicherung in das Sozialgesetzbuch (Unfallversicherungs-Einordnungsgesetz UVEG)" from August 7, 1996, defines the term "accident" in the social accident insurance, as expressed since January 1, 1997, in 8 I Sozialgesetzbuch (SGB) VII. This legal definition widely corresponds to the definition in the private accident insurance as well as to the previous interpretation known from the literature and the jurisdiction.

Accidents↗
PubMed1995

[Dura-plasty in intracranial operations].

Due to recent reports of slow-virus infections related to the use of lyophilized homologous grafts for duraplasty, we have reviewed the concept of dura substitution in cranial neurosurgery. The present study is based upon 2,115 cranial operations from 1991 to 1994. Frequency and complications of different grafts were investigated retrospectively. Within this time period, dura substitution was required with a frequency of 23.4%. In most cases, autologous tissue was used (47.5%), followed by lyophilized or dehydrated and gamma-radiated homologous cadaveric dura and fascia lata (41.8%). In addition, a synthetic polyesterurethane fleece was used since April 1994. In transsphenoidal approaches to the pituitary gland, autologous fascia lata with or without muscle was used exclusively (100%). In frontobasal trauma, plastic covering of the frontal skull base was performed predominantly by autologous galea-periost (84.8%). In contrast, homologous tissues were preferred for duraplasty in the posterior cranial fossa (77.9%). Complications, including CSF fistula, inflammation, pneumatocephalus, and pseudocysts were observed in 13.1% of operations with dura substitution. The rate of complications was highest in infratentorial (20.0%) and frontobasal operations (18.8%). Application of synthetic grafts for 9 months has reduced complications (6.3%). In conclusion, duraplasty should be generally performed by implantation of autologous grafts such as galea-periost or fascia lata. No restriction of this principle should be accepted for surgery in inflammation, after open brain injury, in the frontobasal region and in transsphenoidal approaches to the pituitary gland. In all other cases, insertion of synthetic grafts seems to be equal to the use of autologous tissue, and even superior in large dural defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Dressings↗
PubMed1994

Intracerebral hemorrhage during treatment with oral anticoagulants. Risk factors, therapy and prognosis.

Intracerebral hemorrhage (ICH) during oral anticoagulation is a serious complication, which is mostly fatal for the multimorbid patient. In the present retrospective study of 53 patients with ICH during treatment with a cumarin derivative (Phenoprocoumon, Marcumar), we investigated the relationship between therapy and preexisting parameters such as age, location, level of consciousness, additional bleeding risks, and the degree of anticoagulation, which were assumed to be of prognostic relevance. The therapeutic management of ICH during treatment with anticoagulants was determined predominantly by location of the hematoma, patient's age, and additional bleeding risks, but less by level of consciousness and initial thromboplastin time (Quick's test). As a consequence of the individual analysis of these 5 parameters, age over 60 years, location of hematoma in the midline or ventricles, coma, additional bleeding risks such as arterial hypertension and trauma, and Quick's test below 15% at the time of bleeding were supposed to be responsible for poor prognosis. Mortality increased with a rising number of poor prognostic factors, independently of surgical or conservative treatment. In consequence, prognosis of ICH during oral anticoagulation is predominantly influenced by the number of such disadvantageous indicators and only little by therapy.

Administration, Oral↗
PubMed1993

The growth potential of ependymomas with varying grades of malignancy measured by the Ki-67 labelling index and mitotic index.

The prognostic significance of histopathological grade for postoperative outcome is not yet known for ependymomas. Data on proliferation kinetics of these tumors are few. In our study, the growth fraction was immunohistochemically determined by labelling cell nuclei with the monoclonal antibody Ki-67 in 24 tumors of the ependymoma group (2 malignant ependymomas grade III, 11 ependymomas grade II, 8 spinal ependymomas, and 3 subependymomas). The results were compared with the mitotic index in the same tumor areas. Both growth parameters are related to the grade of malignancy. The differences between the results of spinal ependymomas (grade I) and of intracranial tumors (grade II) were statistically significant. Malignant ependymomas had the highest values. Variable growth potentials could be demonstrated in a few tumors. A non-linear relationship between growth fraction and mitotic index was found, indicating a variable generation time in ependymomas (as in astrocytomas). Thus, with rising grade of malignancy the growth fraction increases and the generation time decreases.

Adolescent↗
PubMed1993

NMR-contrast enhancement of experimental brain tumors with MnTPPS: qualitative evaluation by in vivo relaxometry.

The applicability of the synthetic manganese porphyrin MnTPPS as tumor-selective MRI-contrast agent for brain tumors was investigated quantitatively by in vivo relaxometry. To exclude toxic effects of side products, the purification method for MnTPPS was improved. As a result, MnTPPS+Cl- (free acid) with a purity of more than 99.8% was obtained. For the in vivo quantification of the contrast effect the magnetization M(0) and the transversal relaxation time T2 were evaluated in different regions of rat brains with or without implanted gliomas and in temporal muscle. Measurements were performed before and after the application of MnTPPS. The ratio of the magnetization M(0) (TR = 3.5 sec) of the tissue under investigation and the contralateral striatum was defined as contrast ratio Rc(0). Without MnTPPS Rc(0) of edema (0.93 +/- 0.08) and tumor (0.91 +/- 0.07) did not differ from normal brain tissue (corpus callosum: 0.96 +/- 0.07; cortex: 0.98 +/- 0.05). T2 of edema (110 +/- 12 msec) and intracranial tumor (93 +/- 7 msec) were significantly longer than in normal tissue (corpus callosum: 73 +/- 8 msec; parietal cortex: 75 +/- 6 msec; striate nucleus: 78 +/- 7 msec, p < .01). Two hours after the injection of MnTPPS, magnetization of neoplastic tissue was selectively enhanced (TR = 3.5 sec), and T2 was reduced. The smallest dose of 0.06 mmol/kg body weight (bw) increased Rc(0) to 1.12 +/- 0.04, and 0.38 mmol/kg to 1.30 +/- 0.13 (p < .01). T2 of tumor decreased to 85 +/- 6 msec after 0.06 mmol/kg and to 65 +/- 6 msec after 0.38 mmol/kg bw.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Clinical aspects and pathology of intracranial subependymoma--18 personal cases and review of the literature].

Intracranial subependymomas are rare, benign tumours (WHO grade I) occupying a special position compared to the other ependymal neoplasms. They often remain asymptomatic and, in consequence, are found incidentally at autopsy. In the present study clinico-pathological data of 84 symptomatic (8 own cases) and 58 asymptomatic tumours (10 own cases) are summarised. Subependymomas are more frequently situated in the fourth (58.4%) than in the lateral ventricle (38.0%). They occur predominantly in middle-aged and elderly males. Tumours in the lateral ventricles manifest themselves more often than those in the fourth ventricle. In general, asymptomatic subependymomas do not exceed a diameter of 1.2 cm. The nature of symptoms, with a median symptomatic period of 12 months, is usually associated with hydrocephalus, which is present in more than 80% of the symptom-producing subependymomas. Growth within the ventricular lumen and sharp demarcation from the surrounding brain tissue allow a complete removal in half of the cases. Radical extirpation can be achieved more often in patients with subependymomas located in the lateral ventricles than in those with tumours arising from the floor of the fourth ventricle. The high operative mortality, at a rate of 28.8% so far, mainly refers to the period before microsurgical technique was established. Recurrences are very rare, spinal seeding has not been found to date. For the assessment of long-term results further detailed compilation and documentation of individual follow-ups is necessary.

Adolescent↗
PubMed1993

Polyamine metabolism in experimental brain tumors of rat.

Biosynthesis and accumulation of the polyamines putrescine, spermidine, and spermine are closely associated with cellular growth processes. We examined polyamine levels and the activity of their first rate-limiting enzyme, ornithine decarboxylase (ODC), in stereotactically induced experimental gliomas of the rat brain 1 and 2 weeks after implantation. Regional ODC activity and polyamine levels were determined in the tumor and in the ipsi- and contralateral striatum, white matter, and cerebral cortex. In the tumor, both ODC activity and polyamine levels markedly increased with progressive tumor growth, as compared to those in the white matter of the opposite hemisphere. In the peritumoral brain tissue, ODC activity did not change, but there was a marked increase of putrescine and, to a lesser degree, of spermidine and spermine almost throughout the whole ipsilateral hemisphere. ODC activity, therefore, seems to be a reliable marker of neoplastic growth in the brain, which may be of use for new clinical concepts of the diagnosis and therapy of brain tumors. The more diffuse distribution of polyamines, however, may be associated with the formation and spreading of edema, which would explain some of the biological effects of tumors on distant brain tissue.

Animals↗
PubMed1992

T1 snapshot FLASH measurement of rat brain glioma: kinetics of the tumor-enhancing contrast agent manganese (III) tetraphenylporphine sulfonate.

The ultrafast inversion recovery snapshot FLASH technique was used to determine the kinetics of the contrast agent manganese (III) tetraphenylporphine sulfonate (MnTPPS) in experimental brain tumors in rats. In the first part of the investigation this technique was validated with the conventional inversion recovery spin-echo method by comparing in vivo T1 data of a normal rat brain. Agreement between T1 values obtained from both techniques was complete, as tested for a large number of pixels in identical coronal slices. In the second part the fast IR snapshot FLASH method was applied to study the effect of the NMR contrast agent MnTPPS on the T1 relaxation time of experimental gliomas in rat brains. T1 of normal brain tissue (1024-1035 ms), tumor (1217 ms), and edema (1199 ms) was determined with the inversion recovery version of the snapshot FLASH imaging technique. After intraperitoneal injection of MnTPPS (0.25 mmol/kg body wt) T1 decreased exponentially to 56% of control in tumor and to 62% in muscle. In normal and edematous brain tissue no significant changes in T1 were observed up to 5 h after injection of the contrast agent. Once the T1 contrast between tumor and peritumoral brain tissue had reached a saturation, the enhancement persisted for several hours to days. Therefore application of this contrast agent resulted in a sharp demarcation between glioma and peri-tumoral edema.

Animals↗
PubMed1992

Identification of intracranial liqor metastases of experimental stereotactically implanted brain tumors by the tumor-selective MRI contrast agent MnTPPS.

Two cases of stereotactically induced and spontaneously metastasizing neoplasms in the rat and the cat brain are reported. In the rat, a malignant Schwannoma derived from initially supratentorially implanted RN6 cells developed a second tumor in the posterior cranial fossa. In the cat, a highly malignant polymorphous anaplastic glioma induced by implantation of cloned rat glioma cells (F98) into the left internal capsule developed small tumor cell nests along the ependyma of the ipsilateral ventricle. In precontrast magnetic resonance imaging (MRI) of both cases, the primary tumor was detectable only by a very weak hypointensity and through a shift of the midline. No metastases were apparent. Application of the metallated paramagnetic porphyrin derivative manganese(III) tetraphenylporphine sulfonate (MnTPPS) resulted in a remarkable contrast enhancement between tumoral and normal tissue, which was evident not only in the primary tumor but also in the small metastases. These observations demonstrate for the first time that MnTPPS is an efficient MRI contrast agent for the detection of metastases from primary brain neoplasms and, in consequence, support the hypothesis of its selective binding to tumor cells.

Animals↗
PubMed1992

Spontaneous intracerebral hemorrhage from an unsuspected ependymoma in early infancy.

A case of spontaneous intracerebral hemorrhage from an occipital ependymoma grade 2 in a 3-month-old boy is reported. The infant died 3 days after surgery. The clinical and pathomorphological characteristics are described. Despite the usually rich vascularization of these tumors, hemorrhages from intracranial ependymomas are relatively uncommon. The different forms and probable causes of bleedings are discussed.

Brain Neoplasms↗