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Biomedical subjects

W Zaunbauer

Publications and source records attributed to W Zaunbauer.

At least 19 recordsLinked to original sources
PubMed1999

Impaired somatosensory discrimination of shape in Parkinson's disease: association with caudate nucleus dopaminergic function.

Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a demanding task involving somatosensory pathways and higher cognitive processing. The objects for somatosensory discrimination, i.e., rectangular parallelepipeds differing only in oblongness, were presented in sequential pairs to normal volunteers and 12 parkinsonian patients. The performance of patients was significantly impaired compared to normal volunteers. From a biochemical point of view, the patients were characterized by a severely reduced 6-[18F]-fluoro-L-dopa (FDOPA) tracer metabolism in the basal ganglia, as measured using positron emission tomography (PET). Furthermore, reduced specific FDOPA metabolism in the putamen was consistent with the impaired motor capacities of the patients. The reduced specific FDOPA-uptake within the caudate nucleus was associated with additionally diminished somatosensory discrimination. This association, of low perception during task performance and decreased FDOPA-uptake, provides direct evidence for the role of the caudate nucleus in the cognitive part of the task. We suggest that directed attention and working memory were critically involved as a result of disturbed interactions between the head of the caudate nucleus and the dorsolateral prefrontal cortex. Furthermore, there were indications of an additional involvement of the mesolimbic system, which might be of importance during challenging situations such as forced choice. We conclude that differential effects on parts of the basal ganglia, during evolution of the degenerative process characteristic of Parkinson's disease, have profound consequences on the performance of skills, as shown here for a somatosensory discrimination task.

Adult↗
PubMed1996

[Radiodiagnosis of gastrointestinal lymphomas].

Radiological synopsis of primary gastrointestinal lymphoma depends on the growth direction and dynamism of the tumor, i.e. grade of malignancy and stage of the pathological processes at diagnosis. Initial nodal-polypoid lesions, because of their mucosal/submucosal aggregation, in combination with more or less pathological small bowel relief, are successfully diagnosed by conventional barium studies. Progressive ulcerous and narrowing destruction of the gut wall, as a result of the advanced mural infiltration, increases the success rate of tomographic examination. Tomographic imaging, particularly computed tomography, is considered the primary method, alongside the selective small bowel double-contrast study for demonstration of diffuse tumor infiltration.

Barium Sulfate↗
PubMed1996

[Bronchogenic cyst. A rare benign esophageal tumor].

A case of confirmed esophageal bronchogenic cyst is reported. We review the clinical and pathologic features of this rare congenital foregut anomaly, and emphasize its radiographic appearances with special reference to differential diagnosis.

Adult↗
PubMed1996

Elevation deficit caused by accessory extraocular muscle.

PURPOSE: To report an elevation deficit, which was caused by an accessory extraocular muscle, in a 6-year-old boy. METHODS: Computed tomography and magnetic resonance imaging were used to confirm an accessory, fusiform, well-defined, solid structure in the retrobulbar space. RESULTS: A supernumerary intraconal muscle was detected between the annulus of Zinn and the posterior part of the left globe. CONCLUSION: This rare anomaly may represent an atavistic retractor bulbi muscle.

Child↗
PubMed1995

[Magnetic resonance tomography of hypophyseal tumors].

After describing the topographical anatomy of the pituitary gland, the sellar and parasellar region, in magnetic resonance (MR) imaging, the morphology of pituitary adenomas in MR imaging will be discussed and illustrated, with special reference to differential diagnostic aspects. The diagnostic information and the present clinical relevance of MR imaging, both in pretherapeutic and follow-up situations, will be considered. This will be done using unenhanced and gadolinium-enhanced T1-weighted spin-echo sequences in coronal as well as in sagittal cross sections at 1.5 tesla. Using MR imaging, questions of therapeutic significance concerning the definition of the tumor (evidence of its presence, size, the extent and the degree of infiltration) can be answered with greater precision. The procedure can be repeated with consistency. The contribution of magnetic resonance imaging to tissue characterization is limited. The latter requires consideration of the clinical symptoms and endocrine laboratory findings for differential diagnostic purposes. As disadvantages of MR imaging we should mention the exclusion of certain classes of patients (e.g. those with cardiac pacemaker), the limited potential for evaluation of the extent of invasion of the dura, poor visualization of calcification and insufficient recognition of changes in compact bone.

Adenoma↗
PubMed1988

[Computed tomographic diagnosis of dissecting aneurysm of the aorta].

Twenty-four patients with dissecting aortic aneurysms have been examined by CT and possible causes of mistaken diagnosis are discussed. Failure to diagnose a dissection by CT may be due to atypical localisation and thrombosis of the aortic dissection; dissections of small volume, particularly in the ascending aorta; failure to demonstrate an intimal flap and inadequate contrast enhancement. A false positive diagnosis may be due to fibrotic, inflammatory or neoplastic periaortic changes, aneurysm of the sinus of Valsalva, or artifacts.

Aged↗
PubMed1987

Computed tomography in acute pyelonephritis.

The computed tomographic findings in nine female patients with acute pyelonephritis were reviewed. The major impact of CT was the demonstration of renal enlargement, abnormal contour, perirenal inflammatory extension and, on contrast-enhanced scans, abnormal nephrograms and impaired renal function. It was concluded that CT can provide specific information about the nature and extent of the inflammatory process, thus complementing intravenous urography so that appropriate therapy may be selected. Follow-up studies can be helpful in monitoring the progress of a patient.

Acute Disease↗
PubMed1986

[Computed tomographic diagnosis and differential diagnosis of malignant paranasal sinus tumors].

The CT appearances of malignant tumours of the paranasal sinuses are illustrated on the basis of 15 patients, and the differential diagnosis discussed. Malignant soft tissue tumours in the paranasal sinuses are characterised on CT by their non-homogeneous structure; they may destroy the bony margins of the sinus and infiltrate neighbouring regions in certain preferred directions, and they may enhance following the administration of contrast. Precise definition of the malignant tumour by CT permits their exact staging, may help to determine therapy and is valuable for serial observation. It remains to be seen, however, whether the improved radiological diagnosis results in improved prognosis of malignant tumours of the paranasal sinuses.

Adenocarcinoma↗
PubMed1985

[Normal anatomic measurements in cervical computed tomograms].

Radiodiagnostically relevant normal values and variations for measurements of the cervical region, the arithmetical average and the standard deviation were determined from adequate computer tomograms on 60 healthy women and men, aged 20 to 83 years. The sagittal diameter of the prevertebral soft tissue and the lumina of the upper respiratory tract were evaluated at exactly defined levels between the hyoid bone and the incisura jugularis stuni. The thickness of the aryepiglottic folds, the maximal sagittal and transverse diameters of the thyroid gland and the calibre of the great cervical vessels were defined. To assess information about laryngeal function in computerized tomography, measurements of distances between the cervical spine and anatomical fixed points of the larynx and hypopharynx were made as well as of the degree of vocal cord movement during normal respiration and phonation.

Adult↗