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Biomedical subjects

J Klisch

Publications and source records attributed to J Klisch.

33 records · Page 2Linked to original sources
PubMed2001

Transsphenoidal computer-navigation-assisted deflation of a balloon after endovascular occlusion of a direct carotid cavernous sinus fistula.

SUMMARY: A 49-year-old woman with a direct posttraumatic carotid cavernous fistula (CCF) was treated with detachable balloons via a transcarotid route. After the procedure, her intracranial bruit, conjunctival injection, and orbital congestion were cured, but the preexistent sixth nerve palsy deteriorated. CT showed one balloon positioned in the posterior portion of the right cavernous sinus and was regarded to be responsible for nerve compression. After surgical exposure by use of a transnasal-transsphenoidal approach under 3D navigation control, this balloon was deflated by puncture with a 22-gauge needle. The previously described symptoms resolved after balloon deflation. This report presents a rare complication of endovascular treatment of direct CCF and a new microsurgical approach to a balloon in a case of nerve compression.

Abducens Nerve Diseases↗
PubMed2001

Lhermitte-Duclos disease: assessment with MR imaging, positron emission tomography, single-photon emission CT, and MR spectroscopy.

SUMMARY: Lhermitte-Duclos disease (LDD) is a rare cerebellar lesion with features of both malformation and benign neoplasm. However, the fundamental nature of the entity, its pathogenesis, and the exact genetic alterations remain unknown. We describe MR findings (including perfusion- and diffusion-weighted images) in two patients with LDD, as well as findings from single-photon emission CT (SPECT), MR spectroscopy (MRS), and fluorodeoxyglucose (FDG) positron emission tomography (PET) that give additional information about tumor pathophysiology. MR imaging usually distinguishes the LDD by its characteristic "tiger-striped" appearance. The regions of increased regional cerebral blood volume (rCBV) within the lesion correlated closely to the regions of FDG-hypermetabolism and high thallium (201-Tl) uptake. Proton MRS revealed an increased level of lactate and decreased level of myo-inositiol and N-acetyl-aspartate, as observed in low-grade gliomas, but decreased levels of choline. Our cases indicate that the functional investigations give additional information about tumor pathophysiology and reflect the histopathologic controversial entity with both characteristics found in low-grade gliomas and characteristics not typical for tumors.

Adult↗
PubMed2000

Fast functional MRA using time-resolved projection MR angiography with correlation analysis.

Most recently, time-resolved 2D MRA after injection of a contrast agent bolus for various applications has been proposed. Similar to conventional digital subtraction angiography (DSA), 2D MR DSA offers the ability to observe the dilution of the bolus in the vascular system during the passage with a temporal resolution considerably below 1 sec. The purpose of this paper is to present strategies to improve the inherent low signal-to-noise ratio of 2D angiograms while retaining some temporal resolution. This can be achieved by applying algorithms for time series analysis as used in functional MRI. The significantly improved image quality is demonstrated on examples from clinical studies from bronchial MRA as well as cardiovascular MRA. In addition to the increased signal-to-noise ratio, correlation analysis leads to suppression of background signals and to a better discrimination of overlapping vessels. Further improvements in the temporal discrimination of vessels is afforded by the use of consecutive multiple contrast agent boli as demonstrated by numerical simulations and experiments.

Artifacts↗
PubMed2000

Supratentorial primitive neuroectodermal tumours: diffusion-weighted MRI.

We report the clinical and pathological findings of supratentorial primitive neuroectodermal tumours (PNETs). These are rare, poorly differentiated, highly malignant neoplasms occurring primarily in young individuals. They frequently show dissemination to the spinal cord and sometimes also beyond neuraxis. Preoperative radiological diagnosis is difficult, due to the nonspecific CT and MRI characteristics. Our findings indicate that diffusion-weighted imaging (DWI) can be used to show the solid portion of the tumour preoperatively and to monitor postsurgical recovery. We describe the MRI findings in three patients with histologically confirmed supratentorial PNET, focussing on the role of DWI for improving the specificity of radiological diagnosis.

Child↗
PubMed2000

Time-resolved projection MRA: clinical application in intracranial vascular malformations.

We report preliminary results of imaging intracranial vascular malformations with time-resolved projection MRA after a bolus injection of contrast median before and after endovascular treatment. Projection angiograms are acquired with a slice-selective snapshot FLASH sequence with a time resolution of two images per second, 40-60 images being acquired consecutively after bolus injection of 15 ml Gd-DTPA. Postprocessing of images in 2D projection MRA by correlation analysis offers several advantages with significant improvement of signal-to-noise, leading to adequate anatomical resolution. Subsecond projection MRA is a reliable technique for imaging intracranial vessels and gives information about the haemodynamics of vascular malformations.

Angiography, Digital Subtraction↗
PubMed1999

Local intra-arterial fibrinolysis without arterial occlusion?

Local intra-arterial fibrinolysis (LIF) is the best choice at present for treatment of acute vessel occlusion in the vertebrobasilar territory and also, in selected cases, in the carotid territory. In almost all cases angiography demonstrates the site of occlusion exactly and gives information about collateral circulation. Contrary to this common approach, we report five patients with severe acute thromboembolic stroke in whom angiography revealed no occlusion of relevant arteries or their main branches. Under the hypothesis of persisting occlusion of perforating arteries to the brain stem we performed LIF in patients with a clinical basilar artery syndrome. Outcome in all but one of them was good following LIF. The clinical details are described and possible reasons discussed.

Adult↗
PubMed1999

Radiological and histological findings in spinal intramedullary angiolipoma.

We report an intramedullary angiolipoma with spinal cord compression studied by MRI, angiography and CT. Angiolipomas of the spine are rare benign tumours containing vascular and mature adipose elements. They are epidural in more than 90 % of the cases; only three cases of intramedullary angiolipoma are described. The clinical picture is nonspecific, but MRI and CT suggest the diagnosis.

Adult↗
PubMed1998

MRI in sporadic Creutzfeldt-Jakob disease: correlation with clinical and neuropathological data.

To ascertain whether increased grey matter signal intensity on T2-weighted images in patients with sporadic Creutzfeldt-Jakob disease (CJD) corresponds to the stage and severity of this disease, we correlated MRI findings in four of our own and previously reported patients with sporadic CJD with the clinical variants, neuropathological changes at autopsy, duration of the disease and survival time after MRI examination. Of 15 patients with the extrapyramidal type of CJD, 10 showed increased signal in the basal ganglia on T2-weighted images. One of seven patients with the Heidenhain variant had increased signal in the occipital cortex. Patients without increased grey matter signal intensity had a longer overall duration of CJD (P = 0.035). Although the interval between onset of neurological symptoms and MRI was not different, patients without increased grey matter signal also survived longer after MRI examination (P = 0.022).

Aged↗
PubMed1996

[Radiologic diagnosis of hypophyseal adenomas].

During the last few years the radiological approach to the diagnosis of pituitary adenomas has changed. In the present article we review the current status of techniques and indications for imaging of pituitary adenomas. First the clinical presentation and pertinent biochemical tests for the various types of adenomas are discussed. Then the important questions to be answered by the radiologists are formulated. With the advent of Magnetic Resonance Imaging (MRI) we have a very powerful tool to image the pituitary gland; however, conventional radiographs, computed tomography and angiography continue to play a role in the evaluation of pituitary adenomas under certain circumstances.

Adenoma↗
PubMed1992

Ketanserin reduces neuronal calcium accumulation and cell death in the hippocampus of the Mongolian gerbil after transient forebrain ischemia.

Excessive neuronal activity combined with an increased release of neurotransmitters is supposed to contribute to the delayed neuronal degeneration in animal models of transient cerebral ischemia. Since evidence is accumulating that serotonin (5-HT) exerts an excitatory effect on neurons via 5-HT2 receptors we tested the hypothesis that 5-HT2 receptor antagonists could protect neurons in the gerbil after transient bilateral carotid occlusion. In a first series of experiments, the 5-HT2 receptor antagonist ketanserin was injected intraperitoneally 15 min prior to 5 min of forebrain ischemia and given twice daily on the following 3 days. At a dose of 10 mg/kg i.p., the number of intact hippocampal CA1 neurons was significantly higher than in the saline-treated group and reached 74% of the sham-operated controls. In addition, the degree of neuronal damage correlated with an increased intracellular Ca2+ content in CA1 pyramidal neurons as revealed by arsenazo(III) staining with a procedure modified for paraffin sections. In a second series of experiments, ketanserin (10 mg/kg) was injected at various times after onset of ischemia. Up to a period of 90 min after ischemia, the number of intact CA1 pyramidal cells in ketanserin-treated animals was still significantly higher than in the saline-treated group. These results indicate that 5-HT2 receptor antagonists may protect neurons against ischemic damage even when the treatment is started after onset of ischemia. It remains to be investigated whether the neuroprotective effect of ketanserin is due to a neuronal action or to an inhibition of cerebrovascular vasospasm.

Animals↗
PubMed1990

Effects of 5-hydroxytryptamine1A-receptor agonists on hippocampal damage after transient forebrain ischemia in the Mongolian gerbil.

The activation of 5-hydroxytryptamine receptors exerts an inhibitory influence on neuronal activity in a way similar to the activation gamma-amino-n-butyric acid and adenosine A1 receptors. Therefore, we hypothesized that 5-HT1A-receptor agonists might exert a neuroprotective effect. We tested the full agonists Bay R 1531 and 8-OH-DPAT and the partial agonists ipsapirone and gepirone in the model of transient global ischemia in the Mongolian gerbil. Ipsapirone protected 53% of pyramidal neurons (p less than 0.05) in the CA1 area of the hippocampus from ischemic damage at a dose of 3 mg/kg. Bay R 1531 showed a powerful neuroprotective effect with 100% preservation of neurons at a dose of 3 mg/kg (p less than 0.001) while gepirone and 8-OH-DPAT were ineffective. These findings suggest that 5-HT1A-receptor agonists might be effective tools for the therapy of cerebral ischemia. However, the varying results indicate that transient forebrain ischemia in the gerbil may not be the optimal model system to demonstrate clearly the neuroprotective activity of these compounds.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMedDate not supplied

Functional MRI of language-related activation in left frontal schizencephaly.

Brain activation associated with covert verb generation was studied in a right-handed patient with an asymptomatic left frontal schizencephaly by functional magnetic resonance imaging. Activation of the dysplastic neuronal tissue lining the cleft and the adjacent cortex was found, indicating participation of the malformed region in physiologic cerebral functions. This finding may have clinical impact in patients with medically intractable seizures due to malformations of the cortical development prior to epilepsy surgery.

Adult↗