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Biomedical subjects

F Gjerris

Publications and source records attributed to F Gjerris.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1991

Sleep in acromegaly before and after treatment with adenomectomy.

Daytime somnolence and fatigue are frequently ignored symptoms in acromegaly. To examine whether sleep apnea or other abnormalities in the sleep structure is the underlying cause, 9 young patients with active untreated acromegaly for 2-7 years were studied with all night polysomnography. It revealed a decrease in REM sleep time in all the acromegalics compared to age- and sex-matched normal subjects (p less than 0.001) and also a reduction in delta sleep (p less than 0.05). None had obstructive sleep apnea. At reexamination 12-15 months posttreatment the daytime sleepiness had disappeared in all patients. REM sleep time increased in all patients (p less than 0.001) to normal level; delta sleep time increased moderately (p less than 0.05). Thus sleepiness in patients with high fasting level of growth hormone (GH) is not related to sleep apnea but more likely to a reduced amount of REM sleep time. By normalizing the GH concentration, REM sleep time became normal and the daytime sleepiness disappeared in all patients.

Acromegaly↗
PubMed1991

In vivo 1H-spectroscopy of human intracranial tumors at 1.5 tesla. Preliminary experience at a clinical installation.

Magnetic resonance spectroscopy (MRS) may contribute to the characterization of intracranial tumors in vivo. Volume selective water suppressed proton spectroscopy offers the possibility to study a number of metabolites in the brain including choline (CHO), creatinine/phosphocreatinine (CR/PCR), N-acetylaspartate (NAA), and lactate. Using the stimulated echo technique we have studied 17 patients with intracranial tumors. In all cases the tumors were classified based on histologic evaluation. The tumor spectra differed considerably from those obtained in healthy brain tissue. The results indicate a relative decrease in the NAA and CR/PCR content. In many cases a lactate peak could be seen especially in the tumors with malignant growth characteristics. Our preliminary results suggest that proton spectroscopy may contribute to the differentiation of brain tumors with respect to benign or malignant growth. However, further research is warranted before a definite conclusion can be drawn.

Adult↗
PubMed1991

Intracranial pressure and cerebrospinal fluid outflow conductance in healthy subjects.

Conductance of cerebrospinal fluid (CSF) outflow (Cout) is an important parameter to be considered in patients with CSF circulation abnormalities. In patients with normal-pressure hydrocephalus it is the single most important parameter in determining if the patient needs CSF shunting. The lower normal limit for Cout has been estimated from the effect of shunting in patients with normal-pressure hydrocephalus, from patients retrospectively reevaluated after recovering from illness, and from patients with known abnormalities in the brain or the CSF system. The true value of Cout in normal individuals, however, has hitherto not been reported. In the present study, Cout has been measured by a lumbar infusion test in eight young volunteers with no suspicion of disease. The mean intracranial pressure (ICP) was 11 mm Hg and a linear relationship was found between CSF absorption and ICP. The mean Cout was 0.11 ml/min/mm Hg and the lower 95% confidence level was 0.10 ml/min/mm Hg. These values are in accordance with those obtained from previous studies.

Adult↗
PubMed1991

Tissue characterization of intracranial tumors by MR imaging. In vivo evaluation of T1- and T2-relaxation behavior at 1.5 T.

The main purpose of this in vivo study was to provide a detailed description of the T1- and T2-relaxation processes in intracranial tumors at 1.5 T. A total of 100 patients were investigated. Optimal experimental conditions were carefully observed, including the use of long TR values. T1 determination was based on a partial saturation inversion recovery sequence covering 12 or 6 data points. T2 determination involved a multiple spin echo sequence with 32 echoes. Calculations included biexponential analysis of the 12-point T1 data and all T2 data obtained. The results were evaluated in accordance with histopathology. The T1- and the T2-relaxation times of the prevailing tumor types were significantly different (p less than 0.0005). However, biologic scatter and overlap between tumor types were considerable. In particular, no discrimination between benign and malignant tumor growth was possible. Biexponential evaluation did not increase the specificity, although a biexponential relaxation behavior was recognized in 37% of the T2 curves. The results indicate that tissue heterogeneity is responsible for most of the scatter in the relaxation times. It is concluded that tissue characterization by MR imaging, based solely on relaxation time measurements, seems to be of no value in the differentiation of intracranial tumors.

Adolescent↗
PubMed1990

[Metastatic spinal compression syndrome. Symptoms, diagnosis, treatment and prognosis].

A retrospective study of 398 patients suffering from metastatic compression of the spinal cord or cauda equina is presented. The study comprised almost all relevant medical records of patients admitted to hospital in the eastern part of Denmark in the period 1979 through 1985. Carcinoma of the lung, prostate, breast and kidney were the most frequent primary malignancies causing spinal compression. Most patients were treated with laminectomy, or radiotherapy or with laminectomy and radiotherapy combined. The effect of the treatment was estimated by evaluation of motor function and sphincter control. Treatment with laminectomy followed by radiotherapy was significantly superior to treatment with laminectomy or radiotherapy alone. But if the patients' motor function and primary tumour were taken into account, no significant difference between the treatments was observed. The efficacy of treatment depended upon the symptoms when the diagnosis was established, and accordingly early diagnosis is of the utmost importance. The incidence of metastatic compression increased during the period covered by the study, and since this condition must not go untreated, awareness of the symptoms, primarily pain, is essential.

Adolescent↗
PubMed1990

Metastatic epidural spinal cord compression. Results of treatment and survival.

All medical records of patients treated for metastatic compression of the spinal cord or cauda equina in the eastern part of Denmark from 1979 through 1985 were reviewed. With regard to treatment response and survival, 345 patients could be evaluated. Carcinoma of the lung (19%), prostate (18%), breast (13%), and kidney (10%) were the most frequent primary malignancies causing spinal compression. The outcome of treatment depended primarily on the patients' condition at the time of diagnosis: 79% of the patients who were able to walk before the treatment remained ambulatory, whereas only 21% of the nonambulatory paraplegic patients and 6% of the paralytic patients regained walking ability. Patients treated with laminectomy followed by radiotherapy seemed to respond better than patients treated with radiotherapy or laminectomy alone, but when the patients' pretreatment motor function was taken into account no significant difference was found between the three forms of treatment. In the subgroup of nonambulatory patients, however, a significantly better restoration of gait was observed in patients treated with the combination of laminectomy and radiotherapy than in patients treated with radiotherapy alone. A longer survival in the group treated with the combination of laminectomy and radiotherapy may reflect that these patients were in a lower stage of disease and thus had a better potential of regaining motor function. The results call for prospective randomized studies.

Adolescent↗
PubMed1990

Brain water accumulation in pseudotumour cerebri demonstrated by MR-imaging of brain water self-diffusion.

We studied brain water self diffusion in pseudotumour cerebri by MR-imaging using single spin echo pulse sequences with pulsed magnetic field gradients of different magnitude. The methods is based on the fact that the movement of water molecules is restricted in brain tissue and that accumulation of water in the brain tissue will enhance the self diffusion of water. In order to evaluate the brain water content in pseudotumour cerebri we compared the water self diffusion coefficient in various regions of the brain in pseudotumour patients with that of healthy controls. Ten patients with pseudotumour cerebri were studied. All had increased ICP and increased resistance to CSF outflow. All patients had normal conventional MR spin echo images without focal lesions and a normal sized ventricular system. All patients had abnormal diffusion images showing increased water diffusion. Some patients had in particular increased diffusion in the periventricular regions, others in the whole brain. The diffusion coefficients in all brain regions of interest were significantly higher in patients than in controls. The findings suggest that patients with pseudotumour cerebri have a convective transependymal flow of water causing an interstitial brain oedema and in addition an intracellular brain water accumulation.

Adult↗
PubMed1990

The effect of nimodipine on ICP and CBF in patients with normal-pressure hydrocephalus.

Eight patients with normal-pressure hydrocephalus (NPH) were studied. The resting mean arterial blood pressure (MABP) was 100 (90-125) mmHg and the mean intracranial pressure (ICP) was 11 (5-17) mmHg. ICP and MABP were continuously measured intraventricularly and intra-arterially, respectively. Changes in global cerebral blood flow (CBF) were estimated by the arteriovenous oxygen difference method. Intravenous nimodipine (15 microgram/kg/hour) was given in the first 2 hours and 30 microgram/kg/hour in the next 2 hours. MABP was reduced 23 (4-47) mmHg (p less than 0.05). ICP was increased 3 (0-10) mmHg (p less than 0.05). CBF was unchanged in the group on the whole, but in 4 of patients a major drop in perfusion pressure was seen, and CBF decreased 6, 11, 23 and 34%, respectively. Thus these findings underline the importance of maintaining the perfusion pressure under treatment with nimodipine.

Aged↗
PubMed1990

Metastatic spinal cord compression. Occurrence, symptoms, clinical presentations and prognosis in 398 patients with spinal cord compression.

We reviewed all medical records concerning patients suffering from spinal cord or cauda equina compression (SCC) secondary to cancer, in the eastern part of Denmark, from 1979 through 1985. During the period the incidence of SCC in cancer patients went up from 4.4% to 6%. However, this increase was not significant. The series comprised 398 cases, with carcinoma of the prostate (19%), lung (18%), breast (14%) and kidney (10%) accounting for 61%. The symptoms were evaluated in accordance with the patients rating of pain, motor deficits, sphincter control and paraesthesia, whereas the clinical manifestations were classified on the basis of motor deficit and bladder dysfunction. During the period preceding the diagnosis of SCC, 83% of the patients suffered from back pain, 67% from deteriorating gait and 48% had retention of the urine. In 35% of the patients there was no sphincter disturbance and 10% had normal sensory function. The outcome of treatment was estimated by changes in motor deficits and sphincter function, and depended primarily on the patients condition at the time of the diagnosis. Of the patients who were able to walk before treatment, 79% remained ambulatory, whereas only 18% of the non-ambulatory patients regained walking ability. Patients treated by decompressive laminectomy followed by radiotherapy apparently had a better response than patients treated with surgery or irradiation alone, but when the patients pre-treatment motor function was taken into account, no significant difference was observed. The study may call for a properly randomized trial with careful stratification of tumour biology, performance status and neurological deficits.

Adolescent↗
PubMed1990

Magnetic resonance imaging, computed tomography, and myelography in the diagnosis of recurrent lumbar disc herniation.

Thirteen patients with recurrent symptoms after lumbar discectomy were evaluated. All the patients were enrolled in the study on the basis of clinical symptoms and signs only. The patients were examined with MRI, CT, and myelography in order to compare a) the clinical findings with the imaging investigations, b) the predictive value of the different investigations, and c) the clinical and investigative results with the operative findings. All patients were operated upon according to the clinical findings, and the surgical results were used as the final diagnosis. In six patients a new disc herniation was detected. In the remaining cases surgery revealed either scar tissue or nothing to explain the recurrence of the symptoms. The three imaging modalities were analysed by receiver operating characteristic (ROC) curves. The areas under the ROC curves were 0.68 for MRI, 0.83 for CT, and 0.43 for myelography. The difference in areas between CT and myelography was significant (p less than 0.05). The results indicate that CT has the highest predictive value for demonstrating the recurrence of a lumbar disc herniation.

Adult↗
PubMed1990

Angiotensin converting enzyme inhibition, CBF autoregulation, and ICP in patients with normal-pressure hydrocephalus.

Fourteen patients with normal pressure hydrocephalus had the autoregulation of cerebral blood flow (CBF) and intracranial pressure (ICP) investigated. In 8 of the patients the effect of Captopril on ICP and CBF was also investigated. The mean arterial blood pressure (MABP) was 109 mmHg (intra-arterially), and ICP was 11 mmHg (intraventricularly). Changes in global CBF were estimated by the arterio-venous oxygen difference method. The autoregulation of CBF was present in 13 of the patients (p less than 0.01). The lower limit of CBF autoregulation was 86% of the baseline perfusion pressure. One hour after 50 mg of captopril perorally, MABP was reduced 16 mmHg, and ICP and CBF were unchanged. The autoregulation was maintained and the lower limit was decreased 19 mmHg. Thus patients would be expected to benefit from captopril treatment in hypotensive anaesthesia.

Administration, Oral↗
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↗