Biomedical subjects

T Villmann

Publications and source records attributed to T Villmann.

11 recordsLinked to original sources

PubMed2006

[Correlation of clinical aspects as well as genotype and phenotype in Wilson's disease on the basis of epidemiologic, clinical and cranial MRI findings].

Wilson's disease, a rare autosomal recessive disorder of hepatic copper transport, is characterized by a varying pattern of hepatic, neurologic and psychiatric symptoms. Currently, about 250 causative mutations of the ATP 7B gene are known. However, a correlation between genotype and phenotype according to these mutations is not yet clear. To elucidate a possible correlation in this study 39 patients with Wilson's disease were subdivided into three groups according to the underlying mutation in group I for homocygote respectively group II for compound heterocygote mutation in H1069Q and group III for other mutations. Clinical subtype and extent of neurologic disturbance as well as epidemiologic aspects, presence of psychiatric symptoms, results of acustically evoked potentials (Wave III, interpeak latency III-V) and findings of cranial MRI were considered. While psychopathological symptoms, the results of acustically evoked potentials and cranial MRI show a correlation to the clinical subtype of Wilson's disease there was no genotype-phenotype correlation on the basis of the mutation in H1069Q. The qualitative and quantitative pattern of results do not show any significant differences in the three groups of genotype. Thus, the time of treatment onset still has most influence on the extent of clinical manifestation and reversibility of the toxic copper accumulation.

Adenosine Triphosphatases↗

PubMed2005

[Classification of Wilson's disease based on neurophysiological parameters].

In addition to hepatolenticular degeneration in Wilson's disease, sensory and extrapyramidal motoric systems are also disturbed. In this study a classification on the basis of neurophysiological parameters (EAEP, VEP, MSEP, TSEP and MEP) was established according to subclinical disturbances of these pathways in patients with Wilson's disease on long-term treatment. A cluster analysis of latencies of these evoked potentials was performed. The results of cluster analysis revealed three types of electrophysiological profiles: type I with normal latencies and types II and III showing different patterns of prolonged latencies. However, there was no correlation between clinical classification and the results of cluster analysis based on the electrophysiological data. The neurophysiological based classification provides additional information about central manifestations and aids in characterizing the progress of the disease.

Adult↗

PubMed2005

Classification of fine-motoric disturbances in Wilson's disease using artificial neural networks.

Patients suffering from Wilson's disease are divided into several types according clinical symptoms only at time of manifestation. Thereby two main subgroups exist: neurologic and non-neurologic types. After long-term therapy the neurological symptoms occurring in hepatolenticular degeneration may be improved but frequently with remaining fine-motoric disturbances which should be used for evaluation of the actual patient state. These disturbances are difficult to assess in an exact and objective manner by clinical examination. Therefore we measured fine-motoric passive and active abilities based on a standardized test set using the VSCOPE-system. The parallel evaluation of all fine-motoric data using an artificial neural network leads to a reclassification of these patients based on actual fine-motoric abilities but not reflecting the clinical classification at time of manifestation.

Adult↗

PubMed2003

[Electrophysiological impairment profile of patients with Wilson's disease].

In addition to hepatic and extrapyramidal motor clinical symptoms, Wilson's disease patients also exhibit subclinical disorders of other central nervous pathways. In this study, an impairment profile is described by means of eight electrophysiological tests (EAEP, MSEP, TSEP, T-VEP, MEP, EEG, heart frequency variability, and SSR) for 37 patients (28 with neurological, nine with tnon-neurological form) undergoing long-term drug therapy. The occurrence in 64.3% of a delayed wave III and/or IPL III-V prolongation in patients with the neurological form makes pathological FAEP the most common form of the disorder, followed by disorders in MSEP, TSEP, MEP, and T-VEP. Patients with the non-neurological form usually have normal values, although latency prolongations occur in isolated cases. The range of evoked potential findings is characterised primarily by latency prolongations, i.e. a demyelinising impairment type, and significant losses of potential hardly occur (except in the MEP). The electrophysiological impairment profile does not include EEG changes or vegetative disorders.

Autonomic Nervous System Diseases↗

PubMed2003

Investigation of fine-motor disturbances in Wilson's disease.

Patients suffering from Wilson's disease (WD) can be divided into two main subgroups: neurologic and nonneurologic WD. We measured passive and active fine-motor abilities of 37 WD patients and 24 randomly selected volunteers. The measurement was based on a standardized test set in a defined environment for detection of disturbed finemotor control. The set contains 5 tests comprising rest tremor, postural tremor, target tapping, forefinger tapping and spiral painting, reflecting different aspects of movement disorders. The tests showed significant differences between neurologic WD and volunteers, especially for tasks defining active control. In neurologic WD we found no differences between subgroups whereas for non-neurologic WD we often detected slight movement disorders. The detected movement disorders cam be interpreted as persistent disorders after long-term therapy.

Adult↗

PubMed2002

[Cerebral MRI and evoked potentials in Wilson disease. Comparison of findings in patients with neurological follow-up].

Wilson's disease is caused by toxic copper accumulation, which leads predominantly to hepatic and basal ganglia damage. Characteristic findings in MRI and electrophysiologic examinations are described according to the occurrence of neurological symptoms. In the present study, 28 patients suffering from Wilson's disease (neurological type) were investigated. The results of MRI are compared with abnormalities of evoked potentials (BAEP, MSEP, T-VEP, MEP). All patients show hypodensities in the basal ganglial area (putamen and GI. pallidus) regularly combined with atrophy of the cerebrum and cerebellum in MRI. Signal abnormalities in the mesencephalic region (46% occurrence) and Nc. dentatus (36% occurrence) are combined with the other findings in variable patterns. Only slight changes are found in the pontine region. BAEP are disturbed in 71% of all cases and MSEP in 46%. Combined abnormalities of BAEP and MSEP were found in 39%. Pathological values occurred with a lower frequency in T-VEP (36%) and MEP (39%). The comparison of MRI findings with electrophysiological data done separately for each patient reveals no strong correlation between both methods. Individual MRI findings do not correspond with the patterns of disturbed evoked potentials and vice versa. Therefore we conclude that these methods, MRI and electrophysiological evaluation, supplement each other. Magnetic resonance imaging and electrophysiological evaluation should be performed simultaneously for therapy monitoring.

Adult↗

PubMed2002

Comparison of clinical types of Wilson's disease and glucose metabolism in extrapyramidal motor brain regions.

In Wilson's disease a disturbed glucose metabolism especially in striatal and cerebellar areas has been reported. This is correlated with the severity of extrapyramidal motor symptoms (EPS). These findings are only based on a small number of patients. Up to now it is unknown whether EPS are caused by various patterns of disturbed basal ganglia glucose metabolism. We investigated 37 patients and 9 normal volunteers to characterize the disturbed glucose metabolism in Wilson's disease more precisely. The glucose metabolism was determined in 5 cerebellar and cerebral areas (putamen, caput nuclei caudati, cerebellum, midbrain and thalamic area) by using (18)F-Fluorodesoxyglucose-Positron-Emission-Tomography ( [(18)F]FDG-PET). The database was evaluated by a cluster analysis. Additionally, the severity extrapyramidal motor symptoms were judged by a clinical score system. Three characteristic patterns of glucose metabolism in basal ganglia were obtained. Two of them may be assigned to patients with neurological symptoms whereas the third cluster corresponds to most patients without EPS or normal volunteers. The clusters can be identified by characteristic consumption rates in this 5 brain areas. The severity of EPS can not clearly be assigned to one of the clusters with disturbed glucose metabolism. However, the most severe cases are characterized by the lowest consumption in the striatal area. When there is marked improvement of EPS impaired glucose consumption reveals a persistent brain lesion. Finally, the neurological symptoms in Wilson's disease are caused by (at least) two different patterns of disturbed glucose metabolism in basal ganglia and cerebellum. The severity of EPS seems to be determined by a disturbed consumption in the striatal area.

Adult↗

PubMed2001

[Central relationship patterns in comparison with different objects].

In the present study the Relationship Episode Paradigm Interviews of 70 female patients with different psychoneurotic diseases were analysed with respect to object-specific patterns with the CCRT method. The most frequent categories are the same in all relationship episodes and in subsamples of relationship episodes with mother and father. These categories are also predominant in episodes with women and men. Relationship episodes with mother do not differ from episodes with father, and relationship episodes with women are not different from episodes with men. But there are substantial differences in relationship episodes with the mother and women and between episodes with the father and men. Patients recount much more positive relationship patterns with women and men than with their parents. This could be understood as a hint of interpersonal resources.

Adult↗

PubMed2000

[Clinical and fine motor therapy assessment in Wilson disease].

At the time of diagnosis and after therapy, we examined 33 patients suffering from Wilson's disease. We applied a standardized diagnostic score system on the basis of clinical signs. Without observing any differences between pseudoparkinsonian and pseudosclerosis subtypes, patients with neurological symptoms significantly improved by 2.33 points. Patients with initially more severe symptoms showed the same improvement as less affected patients. Fine motor disturbances were evaluated using the V-scope system. Finger tapping and drawing a spiral were compared to values of a healthy control group (n = 52). Patients with neurological symptoms showed significantly decreased frequencies in both tests. The clinical score was related to frequencies in finger tapping but not in drawing a spiral. Therefore finger tapping can be used as an objective diagnostic tool to evaluate the severity of Wilson's disease, while spiral testing appears to be a sensitive screening tool.

Adult↗

PubMed1999

Neural maps and topographic vector quantization.

Neural maps combine the representation of data by codebook vectors, like a vector quantizer, with the property of topography, like a continuous function. While the quantization error is simple to compute and to compare between different maps, topography of a map is difficult to define and to quantify. Yet, topography of a neural map is an advantageous property, e.g. in the presence of noise in a transmission channel, in data visualization, and in numerous other applications. In this article we review some conceptual aspects of definitions of topography, and some recently proposed measures to quantify topography. We apply the measures first to neural maps trained on synthetic data sets, and check the measures for properties like reproducibility, scalability, systematic dependence of the value of the measure on the topology of the map, etc. We then test the measures on maps generated for four real-world data sets, a chaotic time series, speech data, and two sets of image data. The measures are found to do an imperfect, but an adequate job in selecting a topographically optimal output space dimension, while they consistently single out particular maps as non-topographic.

Journal Article↗

PubMed1999

[Critical review of the categorical structures of the core Conflictual Relationship Theme Method (CCRT)].

The CCRT-method developed by Lester Luborsky is the most widespread and best established method to assess relationship structures in the field of psychodynamic psychotherapy research. Although its categorical structures are criticised in many different ways there have not been any attempts to modify them. This article points out the inconsistency of the current categorical system and demonstrates first approaches to alternative solutions. For this purpose genetic algorithms are used. Their application in psychotherapy research is demonstrated here for the first time.

Algorithms↗