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F Gjerris

Publications and source records attributed to F Gjerris.

At least 19 recordsLinked to original sources
PubMed1995

[Primary intracranial and intraspinal neoplasms in Denmark 1943-1987].

This is a descriptive study of primary intracranial and intraspinal tumours notified to the national Danish Cancer Registry during the years 1943-1987. A total of 19,317 cases of benign and malignant neoplasms were included over these 45 years with a doubling of the age-standardized incidence rates for both men and women from start till end of the registration period. The trend was mainly explained by markedly increasing rates in the age groups 60 years or above at diagnosis. Approximately some 74% of tumours were derived from the brain tissues and 19% from the intracranial and intraspinal meninges. Meningiomas predominate among women with a male:female ratio of 0.5, while tumours of the brain tissues predominate among men (ratio 1.3). Meningiomas are more frequently encountered as a chance finding at autopsy compared to other types of intracranial and intraspinal tumours. The above-mentioned increase in age-specific incidence is due mainly to improved diagnostic capabilities over the period and a subsequent decrease in the underreporting of these tumour types.

Adolescent↗
PubMed1995

A controlled comparison of myelography, computed tomography, and magnetic resonance imaging in clinically suspected lumbar disc herniation.

STUDY DESIGN: A controlled prospective blinded study. OBJECTIVES: To compare the diagnostic power of myelography, computed tomography and magnetic resonance imaging in the diagnosis of low lumbar disc herniation. METHODS: Eighty patients with monoradicular sciatica were examined by myelography, computed tomography, and magnetic resonance imaging, and all underwent subsequent surgery. The images were evaluated twice in a blinded fashion, and the diagnostic power of the modalities was expressed by a decision-analytic regret function. RESULTS: In 57 patients (71%) a disc herniation at the expected level was disclosed at surgery. The largest amount of diagnostic information was gained from computed tomography, followed by magnetic resonance imaging and myelography. Both computed tomography and magnetic resonance imaging were significantly informative, whereas this was not the case for myelography. CONCLUSION: The results indicate that computed tomography or magnetic resonance imaging should be the first choice for imaging in patients with suspected lumbar disc herniation.

Adult↗
PubMed1995

The effect of nimodipine on autoregulation of cerebral blood flow after subarachnoid haemorrhage in rat.

Disturbance of the autoregulation of the cerebral blood flow (CBF) is frequently seen following subarachnoid haemorrhage (SAH) and is possibly partly caused by cerebral ischaemia. It is well-known, that the calcium channel blocker nimodipine reduces the incidence of cerebral infarction and ischaemic dysfunction after SAH. The aim of the present study was to investigate the effect of nimodipine on autoregulation of CBF in an experimental model of SAH. The autoregulation was investigated in 10 control rats with SAH and in 10 nimodipine treated rats with SAH by serial measurements of CBF using a 133Xenon intracarotid injection method during controlled blood pressure manipulations. In the control rats the autoregulation was severely disturbed, no plateau was found where CBF was independent of changes in the arterial blood pressure (MABP). In rats treated with intravenous nimodipine (0.03 mg/kg body weight/h), CBF was 33.0% higher and MABP 5.3% higher compared with the controls. CBF was found constant in the MABP interval between 60 and 100 mmHg which indicates, that nimodipine improves the autoregulation of CBF after SAH.

Animals↗
PubMed1995

Heterogeneous cerebral glucose metabolism in normal pressure hydrocephalus.

The regional cerebral metabolic rate for glucose (rCMRglu) has never been investigated in large consecutive groups of patients with normal pressure hydrocephalus (NPH), a potentially treatable form of dementia with an unpredictable outcome after shunt surgery. Using PET and 18F-2-fluorodeoxyglucose, rCMRglu was studied in 18 patients who fulfilled hydrodynamic criteria for NPH and in whom a biopsy of the frontal cortex was obtained. When compared with an age matched group of 11 healthy subjects, the patients with NPH showed a significant rCMRglu reduction in all cortical and subcortical regions of interest. Individual metabolic patterns, however, disclosed a large topographical heterogeneity. Furthermore, histopathological examination identified Alzheimer's disease or cerebrovascular disease in six cases, and no parenchymal disease or non-specific degenerative processes in the remaining 12. After separating the patients according to the histological diagnosis, the rCMRglu patterns were still heterogeneous, the abnormalities ranging from focal to diffuse in both subgroups. After shunt operation, 11 patients did not improve or worsened clinically. Six patients improved; of those, two had Alzheimer changes and two cerebrovascular changes in their biopsy. The metabolic pattern of these six patients did not differ from the rest of the NPH group. The results indicate that the NPH syndrome may be non-specifically associated with different degenerative disorders. The metabolic heterogeneity, together with the heterogeneous histopathological findings, indicate the necessity of reevaluating the pathogenesis of the NPH syndrome, and may account for the high variability in the success rate of shunt surgery series.

Aged↗
PubMed1995

Increased brain water self-diffusion in patients with idiopathic intracranial hypertension.

PURPOSE: To investigate changes in brain water diffusion in patients with idiopathic intracranial hypertension. METHODS: A motion-compensated MR pulse sequence was used to create diffusion maps of the apparent diffusion coefficient (ADC) in 12 patients fulfilling conventional diagnostic criteria for idiopathic intracranial hypertension and in 12 healthy volunteers. RESULTS: A significantly larger ADC was found within subcortical white matter in the patient group (mean, 1.16 x 10(-9) m2/s) than in the control group (mean, 0.75 x 10(-9) m2/s), whereas no significant differences were found within cortical gray matter, the basal nuclei, the internal capsule, or the corpus callosum. Four of 7 patients with increased ADC in subcortical white matter also had increased ADC within gray matter. CONCLUSION: Measurement of diffusion coefficients in vivo demonstrated increased local water mobility within subcortical white matter in 7 patients with idiopathic intracranial hypertension that otherwise appeared normal on conventional MR imaging. Further studies are necessary to assess the clinical significance of these observations.

Adolescent↗
PubMed1994

Cerebrospinal fluid flow and production in patients with normal pressure hydrocephalus studied by MRI.

An interleaved velocity-sensitised fast low-angle shot pulse sequence was used to study cerebrospinal fluid (CSF) flow in the cerebral aqueduct, and supratentorial CSF production in 9 patients with normal pressure hydrocephalus (NPH) and 9 healthy volunteers. The peak aqueduct CSF flow, both caudal and rostral, was significantly increased in patients with NPH. No significant difference in the supratentorial CSF production rate was found between patients (mean 0.60 +/- 0.59 ml/min) and healthy volunteers (mean 0.68 +/- 0.31 ml/min). Our method may be useful for investigation and monitoring of patients with NPH before and after ventriculoperitoneal shunt operations.

Adult↗
PubMed1994

Assessment of CSF dynamics and venous flow in the superior sagittal sinus by MRI in idiopathic intracranial hypertension: a preliminary study.

A velocity-sensitive magnetic resonance imaging (MRI) phase-mapping method was used for non-invasive study of cerebrospinal fluid (CSF) flow in the cerebral aqueduct, for indirect calculation of supratentorial CSF production, and for measurement of blood flow in the superior sagittal sinus (SSS). We examined 12 patients with idiopathic intracranial hypertension (IIH; pseudotumour cerebri), and 10 healthy volunteers. The peak caudal and rostral CSF flow in the aqueduct during the cardiac cycle did not differ significantly between the patients and the volunteers. A significant correlation was found between the CSF volume flow amplitude and the resistance to cerebrospinal fluid outflow in the patients (p < 0.05). The calculated mean supratentorial CSF production rate was 0.79 ml/min in the patients and 0.70 ml/min in the controls, but this difference was not statistically significant. However, the MRI measurements suggested CSF hypersecretion in three patients, whereas increased transependymal passage of CSF could have been the cause of negative calculated CSF production rates in two others. A tendency towards lower mean blood flow in the SSS (mean 345 ml/min) in the patients than in the controls (mean 457 ml/min) was found, and in two patients showed very low values. We showed that MRI phase-mapping may be used to study the relative importance of the pathophysiological factors thought to play a role in the development of IIH.

Adult↗
PubMed1994

Brain biopsy in AIDS. Diagnostic value and consequence.

Nineteen male patients with AIDS were investigated by biopsy of brain lesions. Six patients had progressive multiple leucoencephalopathy and no specific treatment was given. Toxoplasmosis (two patients), bacterial abscesses (two cases), viral encephalitis (two patients) and only gliosis (two cases) accounted for almost half of the cases. A fungal infection, a lymphoma and a sarcoma-like tumour were found in three patients. In two patients the biopsy was not diagnostic: one had only necrosis and one had normal findings. The biopsy findings gave reason for modifying the treatment in only three cases. The mean survival rate was relatively short, only 76 days with a range from 1 to 1041 days. Two patients were in a very bad clinical condition at the time of biopsy and one died of a haemorrhagic complication due to the biopsy. In ten cases an autopsy was carried out. In five cases there was agreement between the biopsy and autopsy findings. In the other five cases the autopsy findings differed widely. In our experience we can recommend cerebral biopsy in patients with AIDS only after treatment for toxoplasmosis and mainly to estimate the prognosis.

AIDS Dementia Complex↗
PubMed1994

Increased self-diffusion of brain water in hydrocephalus measured by MR imaging.

We used MR imaging to measure the apparent brain water self-diffusion in 5 patients with normal pressure hydrocephalus (NPH), in 2 patients with high pressure hydrocephalus (HPH), and in 8 age-matched controls. In all patients with NPH significant elevations of the apparent diffusion coefficients (ADC) of brain water were found within periventricular white matter, in the corpus callosum, in the internal capsule, within cortical gray matter, and in cerebrospinal fluid, whereas normal ADCs were found within the basal ganglia. In 2 patients with HPH elevated ADCs were found most prominently within white matter, and in one patient reexamined one year after surgery, ADCs were unchanged in nearly all brain regions. The increased ADC values in hydrocephalus patients may be caused by factors such as changes in myelin-associated bound water, increased Virchow-Robin spaces, and increased extracellular brain water fraction. For further studies of brain water diffusion in hydrocephalus patients, echo-planar imaging techniques with imaging times of a few seconds may be valuable.

Adult↗
PubMed1993

Prognostic parameters in benign astrocytomas.

To elucidate the prognosis of different types of benign astrocytomas and to ascertain whether patients with partially resected benign astrocytomas, or any subtype of these, would benefit from postoperative radiotherapy, we studied retrospectively material comprising 300 patients with benign astrocytomas treated in the period 1956 to 1991. The pilocytic type of astrocytoma was found to have an outstandingly good prognosis and should be regarded as a distinct nosological entity. For the non-pilocytic supratentorial astrocytomas, a multivariate regression analysis showed that age, tumour site, Kernohan grade and lymphocytic perivascular cuffing influenced survival. The proportion of gemistocytes increased with age. After correction for age, the proportion of gemistocytes had no significant influence on survival. It was not possible to demonstrate any influence of radiotherapy on median survival time of patients with non-pilocytic supratentorial benign astrocytomas. The study emphasizes the necessity of a prospective combined multicenter analysis of the effect of radiation on benign astrocytomas.

Adolescent↗
PubMed1993

The effect of tirilazad mesylate (U74006F) on cerebral oxygen consumption, and reactivity of cerebral blood flow to carbon dioxide in healthy volunteers.

BACKGROUND: The 21-aminosteroids are a series of compounds designed to inhibit lipid peroxidation in the cell, and, as such, may have cerebral protective effects. The current study was performed to evaluate the effect of a 21-aminosteroid, tirilazad mesylate (U74006F), on cerebral blood flow, metabolism, and carbon dioxide reactivity. METHODS: Using a double-blind study design, eight volunteers received tirilazad mesylate, and eight others received only vehicle. The cerebral blood flow was measured by single photon emission computerized tomography using 133Xe inhalation in the resting condition at the beginning of the study and after infusion of tirilazad mesylate (1.5 mg/kg) or vehicle. Cerebral oxygen metabolism was calculated from the cerebral blood flow and the measured cerebral arteriovenous oxygen content difference. After both of the above cerebral blood flow measurements, arterial carbon dioxide tension was decreased by voluntary hyperventilation, and, later, increased by breathing an air/carbon dioxide mixture. The relative changes in cerebral blood flow induced by the PaCO2 variations were estimated from the changes in the arteriovenous oxygen content difference. RESULTS: Blood pressure, pulse rate, and PaCO2 were similar before and after the infusion of tirilazad mesylate in both groups, and there was no difference between the groups. The cerebral blood flow and oxygen metabolism did not change after the tirilazad mesylate infusion. The slope of the regression line of relative change of estimated cerebral blood flow and PaCO2 (regression coefficients in both groups, > 0.90) was unchanged after infusion. CONCLUSIONS: Tirilazad mesylate has no effect on cerebral blood flow, cerebral oxygen metabolism, or reactivity of cerebral blood flow to carbon dioxide in healthy volunteers.

Adult↗
PubMed1992

Computerized infusion test compared to steady pressure constant infusion test in measurement of resistance to CSF outflow.

Resistance to cerebro-spinal fluid outflow is together with intracranial pressure the most important parameter in the investigation of patients with disturbances of CSF dynamics. The methods for determination of resistance are either unreliable or too time-consuming for routine clinical use, which has limited the popularity of this kind of measurement. In this paper a method for computerized acquisition and processing of an infusion test is described. A good correlation to a standard technique is documented.

Adolescent↗
PubMed1992

Cerebral blood flow autoregulation in experimental subarachnoid haemorrhage in rat.

Haemodynamic instability is of great importance in clinical management of patients with subarachnoid haemorrhage (SAH). The significance of angiographically demonstrable vasospasm for disturbances of cerebral blood flow (CBF) and cerebral autoregulation has not yet been clarified. The present study was designed to describe disturbances of cerebral autoregulation during the timecourse of experimental SAH (eSAH) in rats. A second aim of the study was to relate the results to a reported timecourse of angiographic vasospasm in the same animal model. Previous studies have shown that the timecourse of angiographically visible vasospasm in eSAH is biphasic with maximal spasm at 10 min and 2 days after induction of eSAH. At 5 days, the vasospasms have resolved. CBF was measured using a 133-Xenon intracarotid injection method which allowed serial measurements of mean hemispheric CBF during controlled manipulations of arterial blood pressure. In this way, an autoregulation curve could be constructed. The present study shows that autoregulation is severely disturbed or even totally absent at 2 and 5 days after eSAH. Thus there seems to be no direct correlation between presence of angiographic vasospasm and impairment of autoregulation, or that the impairment of autoregulation is more protracted than the presence of cerebral vasospasm, presuming a correlation exist.

Acid-Base Equilibrium↗
PubMed1991

Fracture of the lumbar vertebral ring apophysis imitating disc herniation.

Three cases of fracture of the lumbar ring apophysis representing type I, II, and III are described in detail and the natural history of these fractures is discussed. The symptoms of apophyseal fractures are usually low back pain, sciatica, tension signs, and neurological deficits, thus imitating the symptoms of lumbar disc herniation. Plain radiography and magnetic resonance are often inconclusive and computed tomography is essential for the true diagnosis. An explanation of the different types of fractures, based on the osteogenesis of the human vertebra, is proposed. Recognition of these fractures is essential for proper planing of surgery, and apophyseal ring fractures must be suspected when children and young adults show signs of lumbar disc herniation.

Adolescent↗