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Biomedical subjects

A Torvik

Publications and source records attributed to A Torvik.

At least 37 records · Page 2Linked to original sources
PubMed1987

Brain lesions in alcoholics: neuropathological observations.

Examination of the autopsy material from a city hospital in Oslo gave the following results: 1. The brain weight of male alcoholics was significantly lower than that of age-matched controls in all 10-year age groups from 40 to 69 years. The mean weight reduction was 31 g. 2. Combined morphometric and histologic studies demonstrated atrophy of the anterior vermis in 42 per cent of all male alcoholics under 70 years of age. In cases over 70 years, 33 per cent of the non-alcoholic controls showed atrophy of the anterior vermis. This is assumed to be a consequence of physiologic ageing. The prevalence of alcoholic cerebellar atrophy could therefore not be determined in this age group. 3. Wernicke's encephalopathy was found in 12.5 per cent of all alcoholics and in 0.8 per cent of all autopsies. One third of the Wernicke cases had acute and subacute lesions while two thirds were chronic. Most of the acute lesions were widespread and severe. The chronic lesions were more restricted but showed great variations in extent and severity within the affected areas. There were corresponding variations in the severity of the clinical symptoms.

Adult↗
PubMed1987

Congenital neuronal ceroid lipofuscinosis. A case report.

A case of congenital neuronal ceroid lipofuscinosis, a 9-day-old male child of Pakistani parents, is reported. Only 5 congenital cases have been described previously. The cerebral and cerebellar cortex showed extensive nerve-cell loss. Granular material with histochemical characteristics of ceroid-lipofuscin was deposited in neurons, macrophages and glial cells throughout the brain. Similar material was found in macrophages in the lymphoid system and in certain other organs. Ultrastructurally, the material was identical with that described in the infantile type of ceroid lipofuscinosis. It is pointed out that the metabolic exchange between the blood of the mother and the foetus is not sufficient to prevent the intra-uterine progression of the disease.

Brain↗
PubMed1986

The prevalence of alcoholic cerebellar atrophy. A morphometric and histological study of an autopsy material.

The Purkinje cell densities in the cerebellar vermis were determined in 31 male alcoholics and 34 non-alcoholic controls under 70 years of age. In addition, all cases were examined histologically for atrophy of the superior vermis. All analyses were performed independently of each other and on randomized slides. The alcoholics had significantly lower Purkinje cell densities than the controls in the superior and middle segments of the vermis. Histologically verified atrophy of the superior vermis was found in 13 of the alcoholics (42%) and in 3 of the controls (9%). There was a good accordance between the morphometric data and the histologic diagnoses. The cause of the cerebellar atrophy in the 3 control cases is uncertain. It could be due to hidden alcoholism or to premature ageing. In a series of non-alcoholic control cases above 70 years, one third of the cases showed atrophy of the superior vermis similar to that of alcoholics. The diagnosis alcoholic cerebellar atrophy should therefore be made with great caution in cases over 70 years. From previous morphometric data on symptomatic cases (Victor et al. 1959), it can be assumed that the majority of the present cases with histologically verified atrophy had overt clinical symptoms. It is concluded that almost one half of all severe alcoholics have atrophy of the superior vermis which can be recognized morphologically and probably also clinically.

Adult↗
PubMed1986

Atrophy of the cerebellar vermis in ageing. A morphometric and histologic study.

Morphometric analysis of the cerebellar vermis in 67 non-alcoholic men between 36 and 94 years of age showed a significant decline in Purkinje cell densities with increasing age in all parts of the cerebellar vermis. However, the nerve cell loss was much more severe in the superior than in the inferior part. There were large individual variations and one-half of the subjects over 80 years showed densities similar to those in the sixties. By independent evaluation, atrophy of the superior vermis was diagnosed histologically in 16 cases, 13 of whom were over 70 years of age. There was a good correspondence between the histologic diagnoses and the morphometric findings. The atrophy involved all 3 cortical layers and the changes were identical to those seen in alcoholics. The diagnosis of alcoholic cerebellar atrophy must therefore be made with great caution in subjects over 70 years of age. Cases with malignant tumours had significantly lower Purkinje cell densities in the superior vermis than those without tumours but the decline with age was of the same magnitude in the 2 groups. The age-dependent atrophy of the superior vermis seemed to be correlated to age alone and not to other known conditions. It probably was sufficiently severe to be recognized radiologically and clinically in a considerable number of the cases.

Adult↗
PubMed1986

Is there a transitional zone between brain infarcts and the surrounding brain? A histological study.

Twenty-eight recent brain infarcts were studied histologically for the presence of zones of partial tissue destruction between the infarct border and the surrounding normal brain. Such transitional zones have been demonstrated in animals and might be suspected in humans from the broad zones of reduced blood flow that have been demonstrated around brain infarcts. Necrotic neurons were observed outside the infarct borders in 20 of 28 cases. However, the width of the peri-infarct border zone was less than 5 mm in 17 of 20 cases and between 7 and 10 mm in 2 cases. Only one section from one case showed necrotic neurons more than 20 mm from the infarct border. It is concluded that the large majority of the brain infarcts in man are sharply delimited and that the broad zones of reduced flow around the infarcts may be due to functional inactivity following partial denervation of the cortex rather than to true ischemia.

Aged↗
PubMed1986

Clivus epidural hematoma: a case report.

An acute traumatic epidural hematoma extending from the odontoid process to the dorsum sella is described. The mechanism for the formation of an extradural hematoma in this unusual location seems to be related to age and a severe hyperflexion injury.

Brain↗
PubMed1985

Combined modality treatment of operated astrocytomas grade 3 and 4. A prospective and randomized study of misonidazole and radiotherapy with two different radiation schedules and subsequent CCNU chemotherapy. Stage II of a prospective multicenter trial of the Scandinavian Glioblastoma Study Group.

A prospective and randomized trial has been performed in order to evaluate combined modality therapy in patients with astrocytomas grade 3 and 4. Follow-up information is available on 244 patients. One half of the series received radiation therapy twice a week (40.00 Gy/5 weeks), the other half five times a week (50.00 Gy/5 weeks). Misonidazole 1.2 g/m2 was given orally to one half of the patients in the first radiation treatment group 3 1/2 to 4 hours before the treatment. The other half received placebo. The second radiation treatment group was also divided in two halves, one receiving 0.48 g/m2 misonidazole and the other placebo 3 1/2 to 4 hours before radiation. The randomization also included a subdivision of the material into eight groups of which four were given CCNU and four no chemotherapy, beginning 3 months after operation. The dose of CCNU was 120 mg/m2 body surface every 6 weeks. All eight treatment groups showed practically identical periods of median survival, and no statistically significant differences were observed with regard to performance status, side effects, or complications. Another dosage and timing of misonidazole administration in relation to the irradiation schedule, and a consideration of effects of concomitant drugs like dexamethasone and phenytoin are discussed.

Actuarial Analysis↗
PubMed1982

The effects of ageing, cachexia and neoplasms on striated muscle. Quantitative histological and histochemical observations on an autopsy material.

The effects of ageing, cachexia and neoplasms on striated muscle were examined in histological sections of an autopsy material. Paraffin sections were examined from four separate muscles of 30 previously healthy subjects who died suddenly, from eight cases with cachexia and from 16 cases with cachexia and neoplasms. In addition, ATP-ase stained cryostat sections were examined from two muscles from most of the cases. All the sections were evaluated with regard to atrophy, myopathic changes and fibre type grouping. Furthermore, the exact size of 100 fibres of each type was determined in the enzyme stained sections. Myopathic changes were found in a few muscles, mainly in the normal cases. They were considered incidental findings without clinical significance. Fibre type grouping could not be evaluated in the anterior tibial muscle because large clusters of the same fibre type occur normally in this muscle. In the biceps brachii only two normal cases and none of the cachectic cases showed fibre type grouping. A moderate small grouped muscle fibre atrophy was found in normal cases with increasing age. The cases with cachexia showed a marked small grouped atrophy which involved both fibre types. There were only small and uncertain differences between cases with cachexia and tumours and those with cachexia alone. Thus, no changes were observed which could be ascribed to tumours alone. The small grouped atrophy in ageing and cachexia resembled that seen in denervation atrophy but the exact mechanism of the changes remains obscure.

Adenosine Triphosphatases↗
PubMed1982

Brain lesions in alcoholics. A neuropathological study with clinical correlations.

Among 8735 autopsies performed during a 5-year period at Ullevål Hospital in Oslo there were 70 cases of Wernicke's encephalopathy (0.8%) and 152 cases of alcoholic cerebellar atrophy (1.7%). Cerebellar atrophy was found in 26.8% of all examined alcoholics. Twenty-two of the cases with Wernicke's encephalopathy were active (acute and subacute) and 48 were inactive (chronic). Examination of the clinical records showed that stupor and coma were the dominating symptoms in active cases. A pure Korsakoff's psychosis with a selective memory defect was present in about one-third of the cases with inactive encephalopathy while the remaining had more or less pronounced global dementia ("alcoholic dementia"). It is suggested that inactive Wernicke's encephalopathy is the main underlying lesion both in Korsakoff's psychosis and "alcoholic dementia" but that additional lesions are present in the latter group. The brain weight in 545 male alcoholics was compared with that of 586 controls. Cases with non-alcoholic brain lesions were excluded from both groups. In alcoholics the brain weight was significantly lower than in controls in all age groups below 70 years. The mean weight difference was 31 g. The study thus confirmed the existence of a generalized alcoholic brain atrophy.

Aged↗
PubMed1982

Watershed infarcts in the brain caused by microemboli.

Multiple vascular occlusions are frequently found in the leptomeningeal arteries over watershed infarcts in the brain. These occlusions have largely been interpreted as thrombi secondary to slowing of the blood flow. This report suggests that most of the occlusions are microemboli, which may lodge preferentially in these areas, and that they are the cause of the infarcts rather than secondary events. These suggestions are based upon the analysis of three groups of patients. The first group consists of four cases, two of which had atheromatous masses and the other two, tumor emboli in the overlying leptomeningeal arteries. These cases prove beyond doubt that microemboli can lodge preferentially in the watershed areas and cause infarcts in the brain. The second group consists of the cases of watershed infarcts that were precipitated by hypotensive episodes. Only one of these showed occlusion of the overlying arteries, although all of them obviously had slowing of the blood flow during the acute phase. These cases thus discredit the concept that stagnation thrombosis is a frequent event. Finally, three cases with watershed infarcts and vascular occlusions interpreted as platelet microemboli are presented to demonstrate different pathogenetic mechanisms effective in the process of embolization.

Adenocarcinoma↗
PubMed1981

Combined modality therapy of operated astrocytomas grade III and IV. Confirmation of the value of postoperative irradiation and lack of potentiation of bleomycin on survival time: a prospective multicenter trial of the Scandinavian Glioblastoma Study Group.

In a controlled, prospective, randomized investigation, started in 1974, 118 patients with supratentorial astrocytoma Grade III--IV were divided into three groups. Groups 1 and 2 received 45 Gy postoperatively to the whole supratentorial brain. Bleomycin in 15-mg doses and a total dose of 180 mg or placebo was given intravenously three times a week, one hour prior to radiotherapy, during weeks 1, 2, 4 and 5. Group 3 received conventional care but no radiotherapy or chemotherapy. Median survival rates of patients were 10.8 months in Groups 1 and 2, and 5.2 months in Groups 3, a statistically significant difference. With regard to performance, the patients in Group 3 deteriorated faster than patients in Groups 1 and 2. Bleomycin had no positive or negative influence on survival.

Adult↗
PubMed1981

The pathology of experimental obstructive hydrocephalus. A scanning electron microscopic study.

Obstructive hydrocephalus was produced in 14-day old rabbits by injection of kaolin into the cisterna magna. The ependymal lining was studied by scanning electron microscopy. Marked hydrocephalus was present 1 or 2 weeks after the kaolin injection. The ependymal lining adapted remarkably well to the rapid expansion by increasing the surface area of the ependymal cells. No breaks or denudement of the ependymal lining was observed except at the sites of ruptured ventricular synechiae. Generally, these findings confirm previous light and electron microscopic observations on the same model (Torvik et al. 1976; Torvik and Stenwig 1977). The results are discussed in relation to current theories concerning the pathophysiology of acute hydrocephalus.

Animals↗
PubMed1981

Subarachnoid hemorrhage and cerebrovascular spasm. Morphological study of intracranial arteries based on animal experiments and human autopsies.

Artificial subarachnoid hemorrhage (SAH) produced by injection of autologous blood into the cisterna magna in dogs gave rise to considerable narrowing or spasm of the basilar artery and its branches, including the posterior cerebral arteries, as demonstrated by cerebral angiography. Repeated cisternal injections of blood at various intervals produced more severe spasm than a single injection. After perfusion-fixation of the brain, the cerebral arteries were examined by light and electron microscopy. None of the animals showed abnormalities in the intima or media of the vessel walls. Previously reported findings of morphological changes due to spasm could not be confirmed. Postmortem examination of brain vessels from nine patients with SAH and arterial spasm showed no specific changes that could be ascribed to spasm.

Angiography↗
PubMed1980

Encephalomyelitis with polyneuropathy.

Four cases of progressive polyneuropathy and bulbar encephalitis and/or myelitis are described. A carcinoma was found in only one of the cases. It is emphasized that this syndrome may occur in the absence of malignant tumors.

Aged↗
PubMed1978

Lack of labelling of microglial cells following microinjection of [3H] beta-alanine: an electron microscopic autoradiographic study.

Following axotomy of the facial nerve, the uptake of [3H] beta-alanine into different types of glial cells in the facial nucleus was studied by autoradiography. A marked proliferation of microglial cells, predominantly in a satellite position to neurons, was accompanied by a localization of [3H] beta--alanine over astrocytes and oligodendrocytes but not over microglial cells. Microglial cells therefore appear to be a functionally distinct cell type and should not be classified with the macroglia.

Alanine↗