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Biomedical subjects

F Gjerris

Publications and source records attributed to F Gjerris.

At least 73 records · Page 4Linked to original sources
PubMed1990

Computerized analysis of cerebral blood flow autoregulation in humans: validation of a method for pharmacologic studies.

Cerebral blood flow (CBF) autoregulation in the supine position without tilting using systemic ganglion-blockade (trimetaphane camphosulfonas) combined with lower body vacuum is evaluated. Automatic computerized curve-fitting analysis for assessment of the lower limit (LL) of autoregulation is introduced. Global CBF was evaluated using the arteriovenous-O2-difference method in 12 volunteers and in seven patients with chronic arterial hypertension. Classic autoregulatory curves were found in all cases. The LL of CBF autoregulation was 85 +/- 5 mm Hg in the volunteers and 113 +/- 7 mm Hg in the hypertensive patients. In seven of the volunteers, the autoregulatory study was performed twice in 1 day; a small but significant shift of LL toward higher blood pressure (BP) values was observed in the second test (3 mm Hg). In five of the hypertensive patients, regional CBF (rCBF) was measured by single-photon emission computed tomography (SPECT) of inhaled xenon-133. The median global CBF decreased from 62 to 45 ml/100 g/min during the mean arterial BP (MABP) decrease from 110 to 68 mm Hg. The regional distribution of CBF was normal at baseline as well as during hypotension. The method is suitable for pharmacologic studies of cerebral autoregulation.

Adult↗
PubMed1989

[Pulmonary hypertension in children treated with ventriculo-atrial shunt in hydrocephalus].

Four infants treated with ventriculo-atrial shunt for hydrocephalus developed sudden pulmonary hypertension, several years after the first operation. All infants died in spite of replacement of the distal shunt and AK treatment. At necropsy, old microemboli were found in the small lung vessels in two infants whereas the two other infants were suspected of having the same lesions from clinical investigations. The overall frequency for this complication was estimated to be 6.7% (95% CI 1.4-14.3%).

Arteriovenous Shunt, Surgical↗
PubMed1989

Malignancy criteria in computed tomography of primary supratentorial tumors in infancy and childhood.

The CT findings of 11 malignant primary supratentorial tumors in children are compared with those of 38 benign tumors. The malignant tumors were more often laterally placed and surrounded by edema. Irregular tumor shape and high or "mixed" density were more frequent in the malignant group where larger tumor volume was found. The contrast enhancement pattern was also different. Thus, ring enhancement with central lucency was more often seen in the malignant tumors. Seven of the malignant tumors had both irregular shape and edema, while this combination was not present in any of the 38 benign tumors.

Astrocytoma↗
PubMed1989

Increased brain water content in pseudotumour cerebri measured by magnetic resonance imaging of brain water self diffusion.

Brain water self diffusion was investigated by magnetic resonance scanning in 7 patients fulfilling conventional diagnostic criteria for pseudotumour cerebri. Quantitative diffusion measurements were obtained using single spin echo pulse sequences with pulsed magnetic field gradients of different magnitude. In all patients the diffusion images showed an increased diffusion in various brain regions when compared with the diffusion coefficients for corresponding regions in healthy subjects. In 3 pseudotumour patients the increased self diffusion was localized to the periventricular regions, while 4 patients had increased diffusion in the whole brain. The findings indicate the presence of increased brain water content both intra- and extracellularly suggesting that patients with pseudotumour have two defects of pathogenetical significance: intracellular water accumulation and increased resistance to cerebrospinal fluid (CSF) outflow leading to an interstitial oedema.

Adult↗
PubMed1988

Do concentrations of neurotransmitters measured in lumbar cerebrospinal fluid reflect the concentrations at brain level?

CSF concentrations of vasoactive intestinal polypeptide (VIP), cholecystokinin (CCK), noradrenaline (NA) and dopamine (DA) were measured in the lateral ventricles and at the lumbar level in patients with normal pressure hydrocephalus (NPH). The concentrations of VIP (n = 15), NA (n = 10) and DA (n = 10) were significantly higher at the lumbar level than at the ventricular level, whereas the concentrations of CCK (n = 9) were similar at the two sites. A significant positive correlation between the concentrations measured at the two levels was found for VIP (rs = 0.65; p less than or equal to 0.01) and DA (rs = 0.94; p less than or equal to 0.001). The results indicate that the concentrations of transmitter substances measured in CSF at the lumbar level not necessarily are indicative for concentrations measured more centrally. The negative correlations between Evans ratio and L-CSF VIP (rs = -0.76; p less than or equal to 0.001), and between resistance to outflow and V-CSF as well as L-CSF CCK (rs = -0.75); p less than or equal to 0.05) might be explained by a reduction in number of cortical neurons or by disturbances in CSF dynamics in patients with NPH.

Cerebral Ventricles↗
PubMed1988

Glucocorticoid receptors in glioblastoma multiforme: a new approach to antineoplastic glucocorticoid therapy.

Glucocorticoid receptors were measured in tissue samples from 12 patients with glioblastoma multiforme. The receptor was found in all patients. The concentration of glucocorticoid receptor was found to be high in the periphery of the tumour, low in the surrounding brain tissue and low in the central part of the tumour in 6 of the patients. The possible role of the glucocorticoid receptor distribution in relation to growth regulation is discussed. A decreasing receptor concentration found at reoperation in two patients indicates a possible antineoplastic effect of high dose methylprednisolone pulse therapy on glucocorticoid receptor positive glioblastomas.

Adult↗
PubMed1988

Clinical course and prognosis of pseudotumor cerebri. A prospective study of 24 patients.

In a prospective study, 24 consecutive patients with pseudotumor cerebri were followed for an average of 49 months with regular neurologic and ophthalmologic examinations. At the first examination the intracranial pressure was between 18 and 45 mm Hg; several patients had pressure waves up to 70 mm Hg and decreased conductance to cerebrospinal fluid outflow. In the majority, medical treatment, usually with diuretics and acetazolamide, induced a rapid relief of symptoms, but about 25% had a more protracted disease course with persistent headache, asthenia and memory disturbances interfering with daily life. Five patients required a shunt operation. Chronic changes of the optic disc developed in nearly half the patients, and one had optic atrophy and severe visual impairment. Repeated measurements of the intracranial pressure and conductance to cerebrospinal fluid outflow showed that abnormalities can persist for a long time, even in cases without symptoms of intracranial hypertension.

Adolescent↗
PubMed1987

Absence of hydrocephalus in spite of impaired cerebrospinal fluid absorption and severe intracranial hypertension.

Four patients are described presenting papilloedema, increased pressure and reduced CSF absorption--caused by either spinal tumours, leptomeningeal carcinomatosis or encephalitis. Remarkably they all had a normal CT without signs of hydrocephalus. A 24-hour intracranial pressure monitoring showed a mean pressure of 30-35 mm Hg, recurrent plateau waves and high occurrence of B waves. Conductance to CSF outflow studied by a constant perfusion test was severely reduced 0.010-0.026 ml min-1 mm Hg-1 (normal greater than 0.12 ml mm Hg-1 min-1). Despite these findings no ventricular enlargement was seen on serial CT scans. The reason therefore remains unknown. Disappearance of papilloedema and a variable clinical improvement followed shunt-insertion.

Absorption↗
PubMed1987

Resistance to cerebrospinal fluid outflow and intracranial pressure in patients with hydrocephalus after subarachnoid haemorrhage.

Resistance to CSF-outflow (Rout) and intracranial pressure (ICP) were measured in 33 patients with hydrocephalus after subarachnoid haemorrhage (SAH). Eleven patients examined between 10 to 30 days after SAH had high pressure hydrocephalus (HPH). Twenty-two patients had normal pressure hydrocephalus (NPH). All HPH-patients had ICP above 15 mmHg, plateau waves and B-waves, a median Rout of 59 mmHg x ml-1 x min-1 (range 29-100). All NPH-patients had a normal ICP level, no plateau waves, but long periods of B-waves and a median Rout of 22 mmHg x ml-1 x min-1 (range 6-47). Of the 11 patients with HPH six were shunted and five had temporary ventricular drainage. Five patients improved and six died. Of the five survivors only one went back to work. Of the 22 NPH-patients 18 were treated with a shunt, one refused shunt operation and three had normal Rout. Seventeen improved after shunting. At follow-up 12 had a normal social life, 5 lived in a nursing home and 1 was dead. Thus, early development of hydrocephalus after subarachnoid haemorrhage is associated with a high Rout and a high ICP, whereas late (more than one month) hydrocephalus may be associated with normal ICP and high Rout. Patients with NPH and a high Rout have frequent B-waves and should be shunted. Patients with a long interval from subarachnoid haemorrhage to the diagnosis of hydrocephalus often have a normal ICP, low frequency of B-waves, normal CSF-dynamics and need no shunting.

Adult↗
PubMed1987

CSF-amine metabolites in depression, dementia and in controls.

Lumbar CSF concentration of 5-HIAA, MHPG, and HVA were measured in patients with depression, dementia due to normal pressure hydrocephalus (NPH) and in controls. Moreover, ventricular concentrations of the metabolites were measured in patients with NPH. It was aimed to match patients and controls for age, sex, and body height. Non-parametric statistics were used throughout the study. No differences in lumbar concentrations of CSF 5-HIAA, MHPG and HVA were found between the different diagnostic groups. A ventriculo-lumbar gradient of 5-HIAA and HVA being 4:1 and 5:1, respectively, was found in patients with NPH. No correlation between the difference in ventricular and lumbar concentrations and body height was found, suggesting that body height may be an inaccurate measure for the rostro-caudal gradient. Moreover, no correlation between ventricular and lumbar levels of 5-HIAA and HVA was seen.

Biogenic Amines↗
PubMed1987

Cerebral blood flow in patients with normal-pressure hydrocephalus before and after shunting.

Cerebral blood flow (CBF) was measured by xenon-133 inhalation and single photon emission tomography in 17 demented patients with normal-pressure hydrocephalus before and after shunt treatment. All patients had a decreased conductance to outflow (C out) of cerebrospinal fluid as measured by lumboventricular perfusion (C out less than 0.12 ml X mm Hg-1 X min-1). Computerized tomography (CT) scanning, clinical assessment, and neuropsychological grading were performed pre- and postoperatively. The preoperative CBF studies revealed abnormal flow patterns in all patients. Fourteen patients showed moderate-sized, large, or very large central low-flow areas, and four patients had reduced flow bilaterally in the occipital and contiguous temporoparietal regions. After shunting, six patients had a significant reduction in the size of the central low-flow area on the CBF map, agreeing well with the changes of ventricular size on the CT scan. All six patients showed an improvement in either clinical or neuropsychological grading. In 10 of the remaining 11 patients flow patterns were essentially unchanged; one patient deteriorated further. Four of these 11 patients improved on postoperative clinical or neuropsychological testing. Thus, a positive correlation was found between the changes in CBF and the reduction of the ventricular size on the CT scan, but changes in CBF as measured by the present technique did not accompany improvement in the functional state in all patients.

Adult↗
PubMed1987

Relationships between intracranial pressure, ventricular size, and resistance to CSF outflow.

In 230 patients with normal-pressure hydrocephalus, high-pressure hydrocephalus, or benign intracranial hypertension, measurements of the intracranial pressure (ICP), ventricular size, and cerebrospinal fluid (CSF) outflow resistance (Ro) have revealed a linear relationship between ICP and Ro. It is shown that on average the CSF formation rate tends to decrease with increasing ICP. It is also shown that the size of the ventricles increases as the ICP levels off toward normal values. The clinical implication of this is that a small or normal ventricular size in acute or subacute phases does not preclude defective CSF resorption.

Cerebral Ventricles↗