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Biomedical subjects

B Gallhofer

Publications and source records attributed to B Gallhofer.

At least 19 recordsLinked to original sources
PubMed2001

Treatment of alcohol withdrawal: tiapride and carbamazepine versus clomethiazole. A pilot study.

In Germany, clomethiazole (CLO) and benzodiazepines are predominantly used as therapeutic agents in the treatment of the alcohol withdrawal syndrome (AWS). These agents have disadvantages such as sedation, risk of respiratory insufficiency, and cardiovascular complications as well as addictive potential. Alternatively, it could be demonstrated that both tiapride (TIA) and carbamazepine (CBZ) are efficient in the treatment of AWS with less toxicity. However, they seem to be less effective in AWS than CLO as single agents. But no systematic comparison of the combination of TIA and CBZ against an established therapeutic standard can be found in the literature. Therefore, we compared the combination of TIA and CBZ with CLO in two open exploratory studies with matched samples. Outcome parameters were heart rate, blood pressure, complications, withdrawal symptoms (CIWA-Ar scale), and general clinical state (CGI scale). A retrospective evaluation of medical records (30 TIA+CBZ, 30 CLO) was followed by an open prospective study (40 TIA+CBZ, 40 CLO). Both studies revealed similar efficacy in terms of psychopathologic and vegetative symptoms. Vegetative recovery seems to be faster with TIA+CBZ. Results of this exploratory study have to be confirmed by a controlled double-blind study with severity of AWS as an experimental factor.

Adult↗
PubMed2001

Responsiveness of subjective quality of life assessment in schizophrenic patients: a quasi-experimental pilot study.

Responsiveness of quality of life (QOL) assessments in chronic schizophrenic patients was investigated by a quasi-experimental pilot study. Satisfaction ratings were assessed over five time points with an externally imposed disturbing stimulus at the second time point. Despite a markedly high stability, the disturbance provoked a temporally limited decrease in QOL.

Chronic Disease↗
PubMed2001

Cognitive subprocesses and schizophrenia. A. Reaction-time decomposition.

OBJECTIVE: The aim of the study is to demonstrate that deficits of information processing in schizophrenic patients can be isolated with reaction-time (RT) decomposition paradigms. METHOD: Three types of visually presented tasks were applied: simple, disjunctive and choice RT-tasks. RT were split into movement latency and time necessary to execute movements. Comparisons of three samples of schizophrenic patients (295.3) with individually matched (age, sex. education and handedness) healthy controls are presented: Sample 1: 10 drug-naive first-onset patients, Sample 2: 10 neuroleptically treated first-onset patients, Sample 3: 10 neuroleptically treated chronically ill patients. RESULTS: Findings indicate that schizophrenia affects primarily subprocesses in which percepts are translated into appropriate actions (response-selection). Neuroleptic treatment improves processing at this stage but is accompanied by slowing of movement execution. CONCLUSION: Response-selection is selectively impaired in first-onset patients. This disturbance, which might be specific for schizophrenia, can be regarded as indication of a disconnection between frontal and posterior areas.

Adult↗
PubMed2001

Cognitive subprocesses and schizophrenia. B. Maze tasks.

OBJECTIVE: In a companion paper we demonstrated that in reaction-time tasks the response selection stage is selectively disturbed in schizophrenia. The aim of the present study is the investigation of subprocesses, which are incorporated into repeatedly activated loops of cognitive processes and need additional information from working memory. METHOD: Maze tasks of varying complexity (with and without bifurcations) were presented to drug-naive and treated first-onset schizophrenic patients. The tasks had to be solved under easy and difficult motor-conditions. Both patient samples were compared with healthy control groups matched by age, sex, education and experience with the experimental setting. RESULTS: In mazes with alternative routes patients exhibited the expected decrease of performance. However, untreated patients improved under difficult motor conditions. This improvement is smaller after neuroleptic treatment. CONCLUSION: Under difficult motor conditions attention is focused on the execution of movements and thus withdrawn from perceiving irrelevant response alternatives, i.e. the effects of disturbed response selection are reduced.

Adult↗
PubMed2001

Reaction-times and bioelectrical brain signals of drug-naive schizophrenic first-onset patients in identification and classification tasks.

OBJECTIVE: The question of the present study is whether disturbances of response-selection in schizophrenic patients are discernible only if overt motor-actions are required, or also if covert cognitive actions are necessary. METHOD: Visual identification (digits) and classification (dot-enumeration) tasks were presented to 18 drug-naive, first-onset schizophrenic patients and healthy controls. It is assumed that enumeration of more than three dots requires additional cognitive processes as buffering and re-focusing of attention. Reaction-times and 21-channel-EEG were measured. For eye-movement artefact-elimination a new non-parametric regression approach was applied. RESULTS: Reaction-times revealed that in the patient group response selection is lengthened in both tasks. Perception of dot numbers is not affected. Bioelectrical data depicted a left-lateralization of posterior P100 and N 100 in the patient group as well as an enhanced fronto-central P200. CONCLUSION: Whereas in reaction-times of patients only a disturbance of response selection is discernible, bioelectrical measurements also point to an altered organization of perceptive processes.

Adult↗
PubMed2000

The importance of social comparisons for high levels of subjective quality of life in chronic schizophrenic patients.

In schizophrenic patients, quality of life (QoL) studies often find high levels of general life satisfaction and satisfaction in various life domains despite deprived living conditions. Therefore, the usefulness of QoL as an outcome indicator has been questioned. Since social comparison processes have been postulated to be related to the level of satisfaction, this hypothesis was analysed empirically by the present study in schizophrenic patients. Satisfaction and social comparisons of 148 schizophrenic inpatients and 66 mentally healthy controls were examined with regard to the domains 'health' and 'family' by means of a standardised interview. The schizophrenic patients had a history of either long-term (n = 75) or short-term (n = 73) restricted and deprived living conditions. Long-term patients showed significantly higher satisfaction levels than short-term patients. They compared themselves predominantly laterally or downwards with fellow inpatients. Significant relationships between the direction of social comparisons and satisfaction ratings were found in all three samples. Social comparisons proved to be important for the level of satisfaction in schizophrenic patients. Results indicate that experiences of restricted and deprived living conditions induce accommodation processes and response-shifts that should be taken into account in the interpretation of quality-of-life data.

Aged↗
PubMed1999

Cognitive dysfunction in schizophrenia: a new set of tools for the assessment of cognition and drug effects.

Cognitive impairment in schizophrenia must be seen as a disturbance of cortico-sub-cortical connectivity with a neurotransmitter imbalance in a circuitry system, which connects thalamic input with prefrontal processing and supplementary motor cortex and basal ganglia output. The concept of maze-solving behaviour as a continuous cognitive task evoking a conflict between prefrontal cortex and basal ganglia activity is explained and introduced to distinguish between the effects of D2 blocking agents and substances with a predominant 5HT2A receptor affinity, such as clozapine and risperidone. Complex mazes show a cognitive deficit in untreated schizophrenic patients that are impaired by conventional and improved by atypical antipsychotic substances. Processing speed improves most on clozapine, while parallel processing is best supported by the non-sedative atypical substance risperidone. Maze paradigms are presented.

Antipsychotic Agents↗
PubMed1998

Somatized depression as a subgroup of fibromyalgia syndrome.

An increase of depressive symptoms in fibromyalgia patients has been noted in a number of studies. The etiologic significance of this finding remains, however, controversial. We suggest that a subgroup of patients with this symptom combination may be pragmatically classified as suffering from somatized depression. Clinical indicators such as a family history of depressive disorders, circadian disturbances, pronounced loss of appetite or libido, and chronic psychosocial stressors should be assessed and, if present, prompt the initiation of psychiatric evaluation and treatment including pharmaco- and psychotherapeutic modalities. Other psychiatric diseases arising in the differential diagnosis of fibromyalgia are discussed.

Depressive Disorder↗
PubMed1998

The topography of non-linear cortical dynamics at rest, in mental calculation and moving shape perception.

Differential cortical activation by cognitive processing was studied using dimensional complexity, a measure derived from nonlinear dynamics that indicates the degrees of freedom (complexity) of a dynamic system. We examined the EEG of 32 healthy subjects at rest, during a visually presented calculation task, and during a moving shape perception task. As a nonlinear measure of connectivity, the mutual dimension of selected electrode pairs was used. The first Lyapunov coefficient was also calculated. Data were tested for non-linearity using a surrogate data method and compared to spectral EEG measures (power, coherence). Surrogate data testing confirmed the presence of nonlinear structure in the data. Cognitive activation led to a highly significant rise in dimensional complexity. While both tasks activated central, parietal and temporal areas, mental arithmetic showed frontal activation and an activity maximum at T3, while the moving shape task led to occipital activation and a right parietal activity maximum. Analysis of mutual dimension showed activation of a bilateral temporal-right frontal network in calculation. The Lyapunov coefficient showed clear topographic variation, but was not significantly changed by mental tasks (p<.09). While dimensional complexity was almost unrelated to power values, nonlinear (mutual dimension) and linear (coherence) measures of connectivity shared up to 37% of variance. Data are interpreted in terms of increased cortical complexity as a result of recruitment of asynchronously active, distributed neuronal assemblies in cognition. The topography of nonlinear dynamics are related to neuropsychological and neuroimaging findings on mental calculation and moving shape perception.

Adult↗
PubMed1997

The effects of sulpiride on psychomotor performance and subjective tolerance.

In many European countries, the substituted benzamide sulpiride is used with antidepressant indication in the dosage range of 150-300 mg on an outpatient population. This raises the concern of possible impairments of psychomotor performance in this dosage range. To address this question, the psychometric effects of 300 mg of sulpiride in comparison with placebo in 12 healthy volunteers was evaluated in this study. In a randomised, double-blind, two-way, within-subjects (cross-over) design, visuomotor performance was assessed using time estimation, critical flicker fusion, and choice reaction time tasks at baseline and 4 h after oral administration of either 300 mg of sulpiride or placebo. In addition, self-ratings on subjective well-being were obtained. Results were evaluated using analysis of covariance (ANCOVA) with baseline levels as covariates. In healthy subjects, 300 mg of sulpiride caused no alteration in time estimation and choice reaction movement time, whereas critical flicker fusion frequency was lower and choice-reaction decision time were prolonged under medication. Self-rating scales showed no significant differences between sulpiride and placebo. Subjects were not able to tell whether they received placebo or sulpiride. This study indicates that sulpiride is subjectively well tolerated at a dosage of 300 mg. However, using psychometric methods, effects are demonstrable that can be interpreted as a reduction of excitatory arousal without causing the subjective experience of sedation. These results call for caution when prescribing the drug to outpatients.

Acoustic Stimulation↗
PubMed1997

Improvement of cognitive function in schizophrenic patients receiving clozapine or zotepine: results from a double-blind study.

Clinical interest in the so-called atypical antipsychotics currently focuses on the possibility of improving the negative symptoms of schizophrenia and the cognitive dysfunction associated with the disease. While clozapine has been shown to be effective in this respect, no data are available on zotepine. We report on a double-blind randomized study designed to evaluate the impact of zotepine and clozapine on cognitive dysfunction in schizophrenia. Cognitive function was operationalized by a maze test in which patients traversed computer-displayed mazes of increasing complexity. Passage time, route, and motor errors were evaluated. 25 schizophrenic (DSM-IIIR) patients were included in each group. After washout, they were randomized on zotepine or clozapine and given up to 450 mg of substance each. Patients were followed for six weeks and evaluated weekly. We report on a subsample of 26 patients matched for baseline BPRS, SANS, and age. 13 matched healthy persons were recruited as controls. ANOVA with group and course over time as factors was used for analysis. Both clozapine and zotepine achieved a highly significant decrease in overall symptoms (BPRS) and negative symptoms (SANS). Zotepine and clozapine were equally effective. In the maze tests, motor errors in simple mazes were stable over time and differentiated schizophrenics from controls as a "trait" marker. In passage time and maze route, schizophrenics performed worse than controls. An improvement by medication was evident in both medication groups, but was more pronounced in the zotepine-treated group. The study confirms previous results on the efficacy of clozapine and zotepine in treating negative symptoms of schizophrenia. The data presented show for the first time that zotepine is efficacious in improving cognitive dysfunction, confirming this substance's value as an atypical antipsychotic.

Adult↗
PubMed1997

Cognitive function in schizophrenia.

Impaired cognitive function in schizophrenia, once thought to be a secondary effect of the psychosis, is now seen as an enduring and core feature. It has many manifestations, but the most disruptive element is arguably a fundamental defect in the patient's ability to manipulate available information. The magnitude of the cognitive deficit in schizophrenia is considerable and remains relatively stable despite fluctuations in other symptoms. The degree of dysfunction also has a high predictive value for long-term disability. In recent years, more attention has been directed towards cognitive dysfunction in schizophrenia as a result of which assessment scales and diagnostic systems increasingly incorporate cognitive dysfunction as an independent domain. Good cognitive function depends upon the brain's ability to prioritize tasks and to switch from parallel processing to sequential processing when the processing load is excessive. This requires working executive memory. Neuroimaging and functional analyses suggest that such cognitive function relies upon unimpaired prefrontal activity. In addition, there is increasing evidence that antipsychotic drugs with 5-hydroxytryptamine (5-HT)2A-blocking activity produce better cognitive function in patients with schizophrenia than drugs with predominantly dopamine (D)2-blocking activity (conventional neuroleptics). The development of sophisticated, computer-delivered maze tasks has shown that newer antipsychotics, such as clozapine and risperidone, differ from conventional neuroleptics in their effects on cognitive function. The prospects, therefore, are that patients treated with drugs having 5-HT2A-blocking activity will have better cognitive function and will be better able to function in life's roles than will patients treated with conventional neuroleptics.

Humans↗
PubMed1997

The AMDP modules I-IV: recommendations for a standardized acquisition of EEG data in psychiatry. Association for Methodology and Documentation in Psychiatry.

During the last few years, the working group 'Psychophysiology' of the Association for Methodology and Documentation in Psychiatry (AMDP) discussed the possibility of the establishment of defined EEG modules in psychiatry. It was the aim to create a common data pool in order to be able to have access to larger data sets. The installation of such a common data pool was regarded as an important prerequisite for a future diagnostic application of EEG and EP data in clinical practice. The most relevant arguments are: From a statistical point of view, multivariate investigations can be improved when relatively large data sets are available. Subgrouping of patients is facilitated. Different centers have access to different populations of patients. Furthermore, compliance with the recommendations contributes to a reduction in misunderstanding and false interpretation of other investigators' results. The working group 'Psychophysiology' of the AMDP now recommends EEG modules to be registered in psychiatry. The recommendations are based on investigations using these modules in clinical research and practice as well as several years of discussion within the working group. Four AMDP modules (I-IV) are presented: MI: resting EEG (closed eyes), MII: resting EEG (eyes open), MIII: EEG during videotracking, and MIV: EEG during choice reaction time. Recommendations for additional modules are planned in the near future: MV: EEG during geometry test, MVI: EEG during labyrinth test, and MVII: amplitude stimulus intensity function. MIII-MVI is paralleled by an EEG recording so that psychomotor performance can be measured and EEG data under different activation conditions are available. Compliance with the recommendations guarantees the possibility of access to the common data pool. Computer software is available in Berlin.

Electroencephalography↗
PubMed1997

Conventional versus atypical neuroleptics: subjective quality of life in schizophrenic patients.

BACKGROUND: The effectiveness of antipsychotic drugs against positive psychotic symptoms has been demonstrated in many studies, but their effects on quality of life have yet to be clarified. The impact of different neuroleptic therapies on the subjective quality of life of schizophrenic patients is evaluated in a cross-sectional open study. METHOD: During a four-month period a standardised quality of life interview for schizophrenic patients was applied on day 10 after admission; 33 patients on atypical neuroleptics (AAP) were compared with 31 matched patients on conventional neuroleptics (CAP). RESULTS: The AAP group had significantly higher scores in general quality of life as well as in different life domains: physical well-being, social life and everyday life. In separate comparisons of the AAP group, patients on clozapine and risperidone were found to have a higher quality of life score than patients on CAP or zotepine. CONCLUSIONS: The pharmacological profile of clozapine and risperidone may provide a basis for explaining the higher subjective quality of life found in this study. The lower quality of life of the CAP group may possibly be related to intrinsic effects of the conventional antipsychotics.

Adult↗
PubMed1996

Imaging of dopamine receptors with [123I]iodobenzamide single-photon emission-computed tomography in neuroleptic malignant syndrome.

With the tracer [123I]iodobenzamide ([123I]-IBZM), it is possible to image dopamine receptor occupancy with single-photon emission-computed tomography (SPECT). We report follow-up examinations with IBZM-SPECT in neuroleptic malignant syndrome (NMS) to display D2-receptor availability in the acute phase and during the course of remission. A 27-year-old man was admitted with severe akinesia, rigor, tachycardia, fever, and elevated creatine phosphokinase level (CK) after neuroleptic medication. NMS was diagnosed, and treatment was started with dantrolene, amantadine, and dopamine agonists. IBZM-SPECT examination was performed on days 6, 34, 90, 107, 131, and 201. In the acute state of NMS, there was no binding of IBZM to D2-receptors. SPECT reached almost normal values on day 131, but clinical examination still showed a mild parkinsonian syndrome. With SPECT, the D2-receptor occupancy in NMS could be successfully shown in correlation with extrapyramidal signs. IBZM-SPECT may therefore serve to monitor D2-receptor occupancy in patients at risk for NMS.

Adult↗
PubMed1996

Cognitive dysfunction in schizophrenia: comparison of treatment with atypical antipsychotic agents and conventional neuroleptic drugs.

Impaired cognitive function is both a feature of schizophrenia and a side effect of conventional neuroleptics. Maze tests were used to determine the effects on cognition of conventional dopamine antagonist neuroleptics (haloperidol and fluphenazine) and the newer serotonin-dopamine antagonist antipsychotics (risperidone and clozapine). Patients on clozapine or risperidone showed better performance on the maze tasks than untreated patients or patients taking conventional neuroleptics. In particular, patients treated with risperidone or clozapine were better able to maintain motor coordination while they focused on the more complex "frontal" maze tasks which required sequencing and planning. In view of the restrictions on the use of clozapine, it is suggested that risperidone should be more widely used in schizophrenia because it preserves cognitive function better than conventional neuroleptics and is therefore likely to allow patients to have better insight into their illness and to have better long-term quality of life expectations.

Clozapine↗
PubMed1995

Remoxipride versus haloperidol in healthy volunteers: psychometric performance and subjective tolerance profiles.

The aim of the present study was to evaluate the psychometric effects of equivalent clinical doses of remoxipride and haloperidol in comparison with placebo in healthy volunteers. In a double-blind design, either 3 mg haloperidol, 150 mg remoxipride, or placebo were administered to 36 healthy male volunteers ranging in age from 19 to 39 years. Performance was assessed using time estimation, critical flicker fusion, and choice reaction time tasks. In addition, self-ratings on subjective well-being were obtained. In healthy subjects, an acute dose of 3 mg haloperidol caused more severe alteration in cognitive functioning, cortical arousal, and psychomotor performance than a clinically equipotent dose of 150 mg remoxipride. Also, self-rating scales showed that subjective tolerance of remoxipride was partly superior to haloperidol. In general, the results of this study strongly suggest a difference between the psychometric profiles of remoxipride and haloperidol. This difference may be essential for maintaining a high level of compliance, especially in the long-term treatment of psychotic patients.

Adult↗