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T Gasser

Publications and source records attributed to T Gasser.

At least 145 records · Page 8Linked to original sources
PubMed1996

Computational analysis of open loop handwriting movements in Parkinson's disease: a rapid method to detect dopamimetic effects.

We used a computational analysis of open loop handwriting movements and a clinical rating scale for monitoring the effect of apomorphine in 16 patients with early untreated parkinsonism [subsequently L-DOPA responsive, probable Parkinson's disease (PD)], six patients with long-standing PD with L-DOPA associated motor fluctuations, and seven patients with known L-DOPA unresponsive parkinsonism. Subjects were instructed to write fluently concentric circles of approximately 12 mm in diameter. Movements were recorded for two periods of 3 s each, using a digitizing tablet. Mean peak velocity (Vmax) and mean peak acceleration (Amax) were determined. In addition, two sensitive indices describing the degree of automation of handwriting were derived: (a) NCV, calculated as the mean Number of Changes in direction of Velocity per half circle, and (b) NCA, the mean Number of Changes in the direction of Acceleration. Clinical rating was performed according to the Unified Parkinson's Disease Rating Scale part III (UPDRS III). After apomorphine injection, the patients with early untreated probable PD showed significant improvement of Vmax, Amax, NCV, NCA, and UPDRS III scores. Likewise, the patients with long-standing PD improved significantly in all kinematic parameters and UPDRS III scores. Patients with L-DOPA unresponsive parkinsonism failed to change significantly in any of the parameters tested. These observations suggest that the computer-assisted analysis of automated handwriting movements can be used as an objective quick method for quantifying dopamimetic effects on the kinematics of handwriting movements in parkinsonian patients.

Adult↗
PubMed1996

Linkage studies in alcohol-responsive myoclonic dystonia.

A large German family with "myoclonic dystonia with lightning jerks responsive to alcohol" was identified. Eleven affected pedigree members and six obligate gene carriers from five generations were identified. A description of one branch of this pedigree was published in 1964. Our examination 30 years after the initial report confirms the clinical syndrome of a nonprogressive movement disorder characterized by myoclonic jerks affecting the proximal muscles and the muscles of the trunk, accompanied by mild dystonic features in some affected family members. Segregation analysis favors autosomal dominant inheritance with high, but incomplete, penetrance in males and much lower penetrance in females. Linkage analysis was performed using simple sequence repeat polymorphisms (CA repeats) closely associated with or spanning the chromosomal regions containing 15 candidate genes: the gene for early-onset generalized torsion dystonia, DYT1 (chromosome 9q34); the genes for subunits alpha 2, beta 1, and gamma 1 (chromosome 4p12-4q13); for alpha 1, alpha 6, beta 2, and gamma 2 (chromosome 5q31.1-5q31.3); for alpha 4, alpha 5, beta 3, and gamma 3 (chromosome 15q11-15q13); for rho 1 and rho 2 (chromosome 6q14-6q21) of the gamma-aminobutyric acid A receptor; and for the alpha subunit of the glycine receptor (chromosome 5q31). By a combination of pairwise and multipoint linkage analysis, it could be excluded that any of these candidate gene-bearing chromosomal regions contain the disease gene in this family. We also excluded major portions of three chromosomal regions syntenic with mouse chromosome 3, which carries the murine beta subunit of the glycine receptor.

Adolescent↗
PubMed1996

Clinical symptoms and possible anticipation in a large kindred of familial restless legs syndrome.

Idiopathic restless legs syndrome (RLS) frequently follows an autosomal dominant inheritance with a variable clinical expressivity of symptoms. We describe the largest German kindred of familial RLS with 20 affected and investigated members in four generations with a variety of clinical symptoms. Patients were examined clinically, and polysomnography was performed in selected cases. The diagnosis was set according to the diagnostic criteria of the International RLS Study Group. All patients showed sensory symptoms of their legs and a worsening of symptoms with increasing age. Older patients, who needed treatment, responded well to opioids. Segregation ratios were close to 0.5, confirming a virtually complete penetrance. The mean age of onset fell from 51.5 years in the second generation to 19.8 years in the fourth generation (ANOVA, p = 0.025). The identification of presymptomatic carriers in the fourth generation in the following years, however, may prejudice this result. This large family showed the variety of clinical RLS symptoms with decreasing age of onset in generations II-IV, suggesting at least the possibility of anticipation.

Adolescent↗
PubMed1996

Development of fat tissue and body mass index from infancy to adulthood.

This paper gives a short overview of our recent research on changes in the body mass index (BMI) or in body fat for children studied longitudinally from birth to adulthood. The BMI shows characteristic changes in childhood and adolescence which are different from those known for skeletal growth. A period of loss of BMI from 1 to 6 years is followed by a pubertal spurt which is larger in females than in males. Fat shows a dramatic increase in the 1st year, and velocity is higher for girls than for boys after 3 years of age. At puberty there is a pre-pubertal and a post-pubertal spurt in total body fat or in arm fat and a dip in between. Those heavy or fat as adults have a qualitatively similar pattern of developmental changes, but much more accentuated fluctuations. The analysis relies on new statistical techniques.

Adipose Tissue↗
PubMed1996

The CYP2D6B allele is not overrepresented in a population of German patients with idiopathic Parkinson's disease.

The frequency of the CYP2D6B allele of the gene for debrisoquine 4-hydroxylase was studied in 115 patients with sporadic idiopathic Parkinson's disease, 55 of their healthy siblings, 63 patients with familial Parkinson's disease, 55 unaffected relatives, and 92 patients with Alzheimer's disease and 73 age matched healthy controls. By contrast with several previous studies, no significant variation of allele frequencies could be found between any of the groups studied. The results argue against a significant role of the CYP2D6 gene in the aetiology of sporadic and familial idiopathic parkinsonism in this patient population.

Aged↗
PubMed1996

Methodology for the establishment of growth standards.

Providing reference values in the form of percentiles for the assessment of paediatric growth is of great practical importance. Extreme centiles are particularly important in the diagnostic process. On the other hand, their statistical variability is inherently large. When measurements approximate to a normal distribution-as for height-centiles can be obtained more accurately. Otherwise, empirical centiles and/or more refined methods are needed. To exploit the age-dependent nature of centiles, smoothing methods are recommended. Accounting for midparental height as a covariate in the calculation of centiles greatly improves their validity due to an increased sensitivity and specificity.

Adolescent↗
PubMed1996

The analysis of the EEG.

The quantitative analysis of the electroencephalogram (EEG) relies heavily on methods of time series analysis. A quantitative approach seems indispensable for research (be it clinical or basic neurophysical research), but it can also be a useful information for purely clinical purposes. Apart from the ongoing spontaneous EEG, evoked potentials (EPs) also play an important role. They can be elicited by simple sensory stimuli or more complex stimuli. Their analysis requires methods which are different from those for the spontaneous EEG. Those methods operate usually in the time domain and offer many challenging problems to statisticians. Methods for analysing the spontaneous EEG usually work in the frequency domain in terms of spectra and coherences. Biomedical engineers who take care of the equipment are usually also trained in time series analysis. Thus, they have contributed much more to methodological progress for analysing EEGs and EPs, compared with statisticians. However, the availability of a sample of subjects, and the associated problems in modelling followed by an inferential analysis could make a larger influence from the statistical side quite profitable. This paper tries to give an overview of a fascinating area. In doing so we treat more extensively problems with some statistical appeal. This leads inevitably to some overlap with our own work.

Artifacts↗
PubMed1995

[Hereditary CADASIL cerebral arteriopathy. Report of a family].

We describe two members of a German family with cerebral autosomal dominant arteriopathy (CADASIL), which is characterized by recurrent subcortical ischemic strokes, mild dementia and leukoencephalopathy. The clinical features of the disease are suggestive of Binswanger's subcortical arteriosclerotic encephalopathy. However, it differs by the lack of hypertension and familial aggregation with autosomal dominant inheritance. Magnetic resonance imaging (MRI) of the brain shows subcortical ischemic infarcts affecting the periventricular white matter, the basal ganglia and the brain stem. On T2-weighted imaging, areas of hyperintensity were found in the white matter of both cerebral hemispheres with preponderance of frontal and anterotemporal regions. We assume that the underlying disease in this family is CADASIL with subcortical infarcts and leukoencephalopathy. The recently assigned disease locus on chromosome 19 was confirmed in this family. A treatment trial with acetylsalicylate was started in the affected members of the family.

Adult↗
PubMed1995

Epidemiological, genetic, pharmacological, kinesiological, nuclear medical (IBZM-SPECT), standard and functional MRI studies on Parkinson's disease and related disorders and economic evaluation of Parkinson's disease therapy--clinical projects in the BMFT-research program Munich: "Parkinson's disease and other basal ganglia disorders".

The results of selected clinical research projects related to epidemiological, genetic, pharmacological, kinesiological, and neuroimaging aspects (SPECT, PET, MRI, functional MRI) of basal ganglia disorders such as Parkinson's disease, Progressive Supranuclear Palsy, Multiple System Atrophy and Wilson's disease are summarized. A retrospective pharmacoeconomic analysis of Parkinson's disease is presented. These studies are part of a nationwide research program of the German ministry of research and technology (BMFT) entitled "Parkinson's disease and other basal ganglia disorders" and were carried out at the Department of Neurology, LMU München.

Basal Ganglia Diseases↗
PubMed1994

Genetic linkage studies in autosomal dominant parkinsonism: evaluation of seven candidate genes.

Linkage studies were performed in three families (A, B, and C) with autosomal dominantly inherited parkinsonism affecting multiple members in three generations. Affected individuals exhibited the cardinal signs and symptoms of Parkinson's disease, with a mean age of onset of 51, 62, and 61 years in Families A, B, and C, respectively. Parkinsonian symptoms responded to L-dopa treatment, and an [18F]6-fluoro-L-dopa positron emission tomography scan in 1 affected member of Family B showed decreased striatal uptake typical of Parkinson's disease. Ancestors of all three families were traced to a small region in northern Germany and southern Denmark, suggesting the possibility of a common mutation. Linkage studies were performed with polymorphic markers associated with the following candidate genes: the genes for glutathione peroxidase (GPX1, 3q11), tyrosine hydroxylase (TH, 11p15.5), brain-derived neurotrophic factor (BDNF, 11p14), catalase (CAT, 11p13), amyloid precursor protein (APP, 21q21), copper-zinc superoxide dismutase (SOD1, 21q21), and debrisoquin 4-hydroxylase (CYP2D6, 22q13.1). Summed lod scores for all families excluded linkage to the genes GPX1, TH, APP, SOD1, and CYP2D6, as well as to the chromosomal region containing the genes CAT and BDNF. If families were analyzed individually, exclusion was possible for two (Family A), six (Family B), and five (Family C) of the seven candidate genes. There was strong evidence against linkage for the remaining loci in all families analyzed individually, except for TH, which was uninformative in Families A and B, and CYP2D6, which gave slightly positive pairwise lod scores in Family A. Our results indicate that the candidate genes investigated are not involved in the etiology of parkinsonism in these families.

Adult↗
PubMed1994

EEG coherence in Alzheimer disease.

A novel approach is introduced to examine EEG coherence in different frequency bands of 17 locations from the 10-20 system. Fifty patients with clinically diagnosed Alzheimer's disease were compared with 42 age-approximated non-demented controls. We determined the average coherence between individual electrodes and all neighbouring electrodes. Coherence was decreased in the sample of demented patients and this effect was most pronounced in the frontal and central derivations of the theta, alpha and beta frequency bands. The results can be interpreted as the effects of neuronal loss and neocortical disconnection.

Aged↗
PubMed1994

Quantitative EEG analysis in early onset Alzheimer's disease: correlations with severity, clinical characteristics, visual EEG and CCT.

We report EEG findings in 15 presenile Alzheimer patients (probable Alzheimer's disease according to NINCDS-ADRDA criteria) in relation to clinical characteristics. The quantitative EEG was analysed in terms of absolute band power while accounting for EOG and EMG artifacts, respectively. The degree of dementia is strongly reflected by an increase of power in the delta frequency band, accentuated on the left hemisphere, as well as decrease of alpha activity. Longer duration of disease is associated with a decrease of power in the alpha frequency band, earlier age at onset with an additional increase of power in the theta frequency band. Visual EEG evaluation correlates highly with the degree of dementia, in contrast to visually assessed CCT.

Age of Onset↗
PubMed1994

Spontaneous perforation of the ureter: a rare complication of urolithiasis.

The spontaneous rupture of the ureter is a rare condition. A case of a girl is reported with a spontaneous perforation caused by ureteral and renal calculi. The concomitant urinoma was drained and the ureter splinted with a double-J catheter. The calculi were destroyed by extracorporal piezoelectric lithotripsy without anesthesia.

Child↗
PubMed1994

Plasma triglycerides and three lipoprotein cholesterol fractions are independent predictors of the extent of coronary atherosclerosis.

BACKGROUND: The lipoprotein system has manifold links to atherosclerotic disease. LDL cholesterol is related to lesion formation and growth. The cholesterol of HDLs is indicative of protection against atherosclerosis. The status of triglycerides and of subfractions of high-density lipoproteins as risk factors is less certain. Also, the magnitude of the atherogenic/protective power of these factors is not known. METHODS AND RESULTS: Five hundred patients (418 men and 82 women) were enrolled in an angiographic study. A total of 1006 coronary lesions with > or = 50% narrowing were recorded as study end points. By extent of atherosclerosis, defined as the number of > or = 50% lesions, the study subjects were allocated to one of four ordered categories with 0, 1 to 3, 4 to 6, or 7 to 10 lesions, respectively. Subfractions of HDL cholesterol were determined by a dual precipitation method. By a polychotomous logistic regression model, it was found that, besides age and sex, LDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, and triglycerides were independently predictive (P < .05) of the extent of coronary atherosclerosis. An increase in age by 10 years was associated with an increase of the odds ratio for falling into a higher-extent category by a factor of 1.64, and the same increase of the odds ratio was obtained by increasing LDL cholesterol by 0.92 mmol/L or triglycerides by 1.01 mmol/L and by decreasing HDL2 cholesterol by 0.20 mmol/L or HDL3 cholesterol by 0.46 mmol/L. The less sensitive coronary end point, presence of atherosclerosis (ie, observation of > or = 1 lesion of > or = 50%) depended significantly on age, sex, LDL cholesterol, and HDL2 cholesterol, but not on HDL3 cholesterol or triglycerides. CONCLUSIONS: In addition to LDL, HDL2, and HDL3 cholesterol, triglycerides also proved independently predictive of the extent of coronary atherosclerosis.

Cholesterol, HDL↗
PubMed1994

The DYT1 gene on 9q34 is responsible for most cases of early limb-onset idiopathic torsion dystonia in non-Jews.

Idiopathic torsion dystonia (ITD) is characterized by involuntary twisting movements and postures. A gene for this disorder, DYT1, was mapped to chromosome 9q34 in 12 Ashkenazi Jewish (AJ) families and one large non-Jewish kindred. In the AJ population, strong linkage disequilibrium exists between DYT1 and adjacent markers within a 2-cM region. The associated haplotype occurs in > 90% of early limb-onset AJ cases. We examined seven non-Jewish ITD families of northern European and French Canadian descent to determine the extent to which early-onset ITD in non-Jews maps to DYT1. Results are consistent with linkage to the DYT1 region. Affected individuals in these families are clinically similar to the AJ cases; i.e., the site of onset is predominantly in the limbs and at least one individual in each pedigree had onset before age 12 years. None carries the AJ haplotype; therefore, they probably represent different mutations in the DYT1 gene. The two French Canadian families, however, display the same haplotype. Estimates of penetrance in non-Jewish families range from .40 to .75. We identified disease gene carriers and, with adjustments for age at onset, obtained a direct estimate of penetrance of .46. This is consistent with estimates of 30%-40% in the AJ population. Two other non-Jewish families with atypical ITD (later onset and/or cranial or cervical involvement) are not linked to DYT1, which indicates involvement of other genes in dystonia.

Adolescent↗