PubMed Health⌕ Search

Biomedical subjects

T Kircher

Publications and source records attributed to T Kircher.

At least 19 recordsLinked to original sources
PubMed2005

[Functional imaging of emotional disorders and experiences in schizophrenia patients].

Functional imaging of normal and dysfunctional emotional processes is an important tool for a better understanding of the pathophysiology of affective symptoms in schizophrenia patients. These symptoms are still poorly characterized with respect to their neural correlates.Comparisons of cerebral activation during emotional paradigms offered the possibility for a better characterization of cerebral dysfunctions during emotional processing in schizophrenia. Abnormal activation patterns reveal a complex dysfunctional subcortical-cortical network. This is modulated by respective genotypes as well as psycho- and pharmacotherapy.

Affective Symptoms↗
PubMed2003

[Neural correlates of "negative" formal thought disorder].

Formal thought disorder (FTD) is a core feature of schizophrenia, but its pathophysiology is poorly understood. It can be conceptualised as 'positive' (e.g. incoherence, neologisms) or 'negative' (e.g. poverty of thought) thought disorder. We investigated the neural correlates of negative FTD. Blood oxygenation level-dependent (BOLD) contrast was measured using functional magnetic resonance imaging (fMRI) while six patients with schizophrenia and six healthy control subjects spoke about seven Rorschach inkblots for 3 min each. Varying degrees of thought-disordered speech were elicited during each run. In a within-subject design, the degree of negative thought disorder, conceptualised as 'poverty of speech' (Liddle et al. (2002) Thought and Language Index. Br J Psychiatry) was correlated with BOLD contrast in the two runs per patient showing the highest variance in this phenomenon. The degree of poverty of speech correlated positively mainly with activation in the right inferior parietal lobe (BA 40), middle frontal gyrus (BA 46), cuneus (BA 18), and the left posterior cingulate (BA 31). Negative correlations were evident in the left hippocampal/fusiform gyrus (BA 35/36/37). The severity of negative FTD correlates with activation in areas previously implicated in autobiographic episodic memory. During symptoms behaviourally characterised as negative, patients may experience rich memories and associations.

Adult↗
PubMed2002

[Effects of autogenic training in elderly patients].

Autogenic training (AT) is a widely available relaxation method with beneficial outcome on physiological and psychological functioning. In our study, we wanted to test the effects of an AT course in cognitively impaired, frail elderly. After a 3 month waiting period (control), AT courses (intervention) of 3 months duration were offered in 2 nursing homes. Thirty-two frail elderly took part in the study, 24 of them had a psychiatric diagnosis (mean age 82.1 +/- 7.2 years, CAMCOG 75.5 +/- 15.7, MMSE 23.3 +/- 4.3, HAMD 10.0 +/- 3.6, NOSGER 57.2 +/- 18.4, AT-SYM 32.9 +/- 17.6 points). Eight participants dropped out during the waiting period, 8 during the course. From the 16 participants, 15 (94%) were able to learn the AT according to subjective, 9 (54%) according to objective criteria. The ability to practice the AT successfully correlated with the CAMCOG (p = 0.001) and the NOSGER (p = 0.01) score. Participants with a dementia syndrome had major difficulties, whereas age, depressiveness, and number of complaints (AT-SYM) had no influence on the ability to learn the AT. There was no intervention effect, measured with the HAMD, NOSGER, AT-SYM and MMSE. In the pre-post comparison of training sessions, a significant improvement in general well being was found (p < 0.001). Mentally impaired, frail elderly participants are able to learn the AT. Cognitive impairment is disadvantageous for a successful participation.

Adaptation, Psychological↗
PubMed2001

Dynamic regulation of EEG power and coherence is lost early and globally in probable DAT.

Electroencephalographic (EEG) findings in dementia of Alzheimer type (DAT) include slowing of alpha frequency, loss of alpha band power, increased theta and delta power and reduced coherence. Here it is evaluated whether a) EEG acquisition during different functional states facilitates the detection of DAT-associated EEG changes, and b) EEG changes in mild DAT are topographically confined or global. Power spectra and coherence of EEGs from 29 patients with mild probable DAT and 28 age- and sex-matched controls were compared during three cognitive states. Group differences in power spectra and coherence were largest during resting with eyes open, yielding a 77% correct classification result. Already in early stages of probable DAT, EEG changes were topographically wide-spread. The task-related up- and down-regulation of power and coherence was impaired already in mild probable DAT. We propose to augment clinical EEG assessment by including a quantitative analysis of the dynamic power and coherence changes from rest, eyes closed to eyes open in suspected DAT.

Aged↗
PubMed2001

Transcranial magnetic stimulation: no effect on mood with single pulse during learned helplessness.

1. Transcranial Magnetic Stimulation (TMS) is suggested to be an effective tool in the treatment of depression. However, the methodology most suitable for clinical application remains unclear. 2. The effect of TMS was tested in a double-blind and placebo-controlled setting on 18 healthy subjects. At the same time an established learned helplessness paradigm was applied to induce dysphoria, which consisted of unsolvable anagrams. 3. Sixty 0.5 Hz stimuli were administered at an intensity of 130% of the subject's motor threshold after the subjects were exposed to the learned helplessness situation. Using a vertically positioned coil, the stimuli were applied to the right or to the left frontal cortex, or on the occipital cortex as a placebo condition. 4. Although dysphoria was successfully induced by unsolvable anagrams, TMS on either of the two frontal locations did not influence mood. This lack of effect may be due to the stimulation characteristics employed here (low TMS intensity, and low frequency). On the other hand, the findings may reflect the neurobiological difference between experimentally induced sad mood and clinical depression.

Adult↗
PubMed2000

Homocysteine--relevant for atherogenesis?

Numerous studies report strong associations between hyperhomocysteinemia and premature atherosclerotic vascular disease. Causes of hyperhomocysteinemia are hereditary heterozygous or, in very rare cases, homozygous defects, and quite frequently a lack of the coenzymes B6 and B12 and the cosubstrate folate. Lifestyle factors, age, sex, acute and chronic illness, vitamin deficiency and certain drugs may elevate homocysteine concentrations. Vitamin B supplementation, especially folic acid, is an effective treatment of hyperhomocysteinemia. Clinical trials are required to confirm the potential benefit of lowering homocysteine in regard of the development and progression of atherosclerotic vascular disease. The relevance of hyperhomocysteinemia as a risk factor for atherosclerosis, in contrast to the classical triad of risk factors, namely hypercholesterolemia, smoking and hypertension, is still unknown. Furthermore, a lack of standardized analytical methods for the determination of both homocysteine and blood folate renders the evaluation of studies and clinical data difficult. Therefore, at present, diagnosis and treatment is only recommended in high-risk patients (strong family history of premature atherosclerosis or arterial occlusive disease, especially in the absence of other risk factors, as well as in members of their families) with hyperhomocysteinemia.

Arteriosclerosis↗
PubMed1998

Cognitive decline unlike normal aging is associated with alterations of EEG temporo-spatial characteristics.

The diagnosis of beginning dementia is based mainly on neuropsychological testing. Several measures of EEG spectral composition, coherence and complexity (correlation dimension) have been shown to correspond to cognitive function. Only a few studies have evaluated EEG changes in normal aging, and no quantitative study has addressed changes in EEG during cognitive tasks in demented elderly. In this study the quantitative descriptors of EEGs from 31 demented or cognitively impaired elderly persons, 30 healthy elderly (mean age 69 years) and 35 young controls (mean age 31 years) were compared. The EEGs were recorded during two resting conditions (eyes closed and eyes opened) and two tasks (mental arithmetics and a lexical decision). The goal of the study was to evaluate which temporal and spatial EEG descriptors change with cognitive decline and with normal aging, respectively. Cognitive categories (unimpaired, impaired, demented) were based on Structured Interview for the Diagnosis of Dementia of Alzheimer Type (SIDAM) scores. The EEGs were analysed using adaptive segmentation of continuous EEG, which quantifies the succession of distinct stable topographic voltage patterns (EEG microstates). The main findings were a significant increase in the number of ultra-short EEG microstates and, independently, a reduction in the average duration of EEG microstates in the cognitively impaired and demented patients. In addition, cognitive impairment was associated with a reduction or loss of EEG reactivity normally observed when the resting states with closed and with opened eyes are compared. No alterations in temporal or spatial EEG descriptors were found in normal aging. Cognitive tasks did not add to information already obtained during the resting states. The reduction in EEG microstate duration correlated with loss of cognitive function. Temporo-spatial analysis of EEG therefore is a useful indicator of cortical dysfunction in dementia, correlating with the degree of cognitive impairment. Normal aging seems not to be accompanied by changes in temporo-spatial EEG patterns. The data suggest that fragmentation of the electrophysiological processes underlies cognitive dysfunction in Alzheimer's disease.

Adult↗
PubMed1996

Beta 2-receptor density on mononuclear blood cells in patients suffering from neuroleptic-induced akathisia (NIA).

The effectiveness of beta-blockers in the treatment of neuroleptic-induced akathisia (NIA) suggests that beta-adrenergic overactivity is involved in the manifestation of NIA. As an approach to understanding this postulated overactivity, we investigated the beta 2-receptor density on mononuclear blood cells in 21 patients suffering from NIA as well as in 12 patients without NIA. The beta 2-receptor density in NIA-positive patients was significantly higher than that in NIA-negative patients (t = 2.84; p = .008). The NIA-positive patients were treated with 20 mg propranolol t.i.d. for 5 days. The beta 2-receptor density in treatment responders did not differ significantly from that in non-responders. Our results indicate that beta 2-receptors on mononuclear cells in patients with NIA may be of a certain degree of importance. With the prerequisites of replicability as well as correlation of this parameter with therapeutic success of beta-blockers, it may be considered as a predictor for treatment response.

Adolescent↗
PubMed1995

Myoglobin in the early evaluation of acute chest pain.

Two thirds of patients hospitalized to rule out acute myocardial infarction (AMI) are eventually found to have a non-AMI diagnosis, whereas 2% to 8% of patients with AMI are inappropriately discharged from the emergency department. Myoglobin has been shown to increase within 2 to 3 hours of myocardial injury. This study evaluates the usefulness of myoglobin in acute chest pain. Serial blood samples were obtained from 89 suspected AMI patients evaluated in the emergency department. Testing included creatine kinase (CK), a creatine kinase isoenzyme (CK-MB), and myoglobin. Twenty five of 89 patients (28%) had a diagnosis of AMI. The sensitivity of myoglobin for the detection of AMI was 56% at the time of admission and 100% 2 hours after admission. Thirteen of 25 AMI patients (52%) had a positive myoglobin before increases in CK or CK-MB, including one patient discharged from the emergency department. More importantly, the negative predictive value for myoglobin at the time of admission was 83% and was 100% two hours after admission. This potential for 100% predictability in excluding AMI by the use of serial myoglobin determinations will be very helpful in the correct triage of patients presenting with acute chest pain.

Acute Disease↗
PubMed1991

Mediastinal ependymoma.

A mediastinal ependymoma in a 35-year-old Caucasian woman is reported. The tumor was located in a paravertebral posterior mediastinal location. No continuity with the spinal canal or with the lung was identified. The diagnosis was confirmed by immunoperoxidase staining for glial fibrillary protein and by the presence of cilia within intracytoplasmic vacuoles. To the best of our knowledge, this is the second reported case of ependymoma in this location.

Adult↗
PubMed1990

The autopsy and vital statistics.

Vital statistics in the United States are collected through a decentralized, cooperative system of various levels of government administrated by the National Center for Health Statistics. Although registration of all deaths is virtually complete and demographic items are accurate, the reliability of cause of death data is hampered by the current state of medical knowledge, the incompleteness of information available at the time of death, the way in which physicians complete death certificates, and the system of classification of underlying cause. The need for quality assurance in national cause of death statistics can be met in large part by connecting the autopsy to the mainstream of vital statistics. Through case by case individual linkage of death certificates and autopsies in designated demographic and/or geographic areas, a representative, continuously collected, population-based system of aggregated autopsy data would be created. Demographic and clinical selection bias should be checked and adjusted through traditional methods of epidemiologic standardization. Such a use of autopsy information could further pathology's goals of understanding disease and improving the public health.

Autopsy↗
PubMed1989

Capillary blood glucose monitor. Evaluation in a newborn nursery.

The performance of a rapid capillary blood glucose monitor, the Glucoscan 2000, was evaluated in a neonatal patient population by comparison with a reference method on 283 paired patient samples. The median glucose was 56 mg/dL (3.1 mmol/L). The slope of the regression line was .93 with a correlation coefficient r of .82. The average error in Glucoscan values at low, intermediate and high glucose ranges was 43%, 20% and 12% respectively. Precision analysis by replicate determinations also showed an increased coefficient of variation, 7.4%, at low glucose values.

Blood Chemical Analysis↗
PubMed1987

Cause of death. Proper completion of the death certificate.

Mortality statistics derived from death certificates are the only continuously collected, population-based, disease-related information available in most parts of the world, including the United States. For this reason, every effort must be made to ensure that the most specific, accurate, and complete information regarding cause of death is registered on death certificates. This article discusses identification of the underlying and immediate causes of death, the mechanism and manner of death, and completion of the medical certification section of the death certificate. Examples are given to illustrate the appropriate sequencing of causal information and the selection of the proper underlying cause of death.

Aged↗