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B Gallhofer

Publications and source records attributed to B Gallhofer.

At least 19 recordsLinked to original sources
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↗
PubMed1993

Psychophysiology, psychoneuroendocrinology, and the laterality concept of the brain.

Twenty-two patients--11 paranoid schizophrenics and 11 major depressed--were investigated by means of a hypothalamic-pituitary challenge (HPC). The latter contained insulin, TRH and metoclopramide. Response with regard to blood glucose, serum GH, PRL, TSH and cortisol were measured 30, 60, 90, 120 and 180 min after the baseline. Temporal alpha power was split into 2 groups with high and low alpha power, respectively. The aim was to see whether high cortical-limbic-hypothalamic-pituitary and hypothalamic-pituitary-adrenal reactivity correlated with high temporal alpha power. Poor results were found with regard to diagnoses. Only TSH and glucose response were correlated with diagnoses. But, GH and cortisol responses reacted in relation to different alpha levels. Cell loss due to hormonal stress and consecutive miswiring of axons due to wrong sprouting are discussed as possible reasons for abnormal lateralized HPC response.

Blood Glucose↗
PubMed1991

[EEG mapping in schizophrenia and depression--a multivariate approach].

EEG Brain Mapping offers a promising approach to study complex pattern of brain function. However, traditional usage of this method was focussed mainly on isolated details of the whole specter. The present study was, therefore, aimed at the simultaneous observation of all available parameters. Discriminant analysis was used to distinguish between 4 groups of patients suffering from either schizophrenia (acute/off drugs; improved/on drugs) or depression (acute/off drugs; improved/on drugs) and healthy volunteers, each group with n = 10. The multivariate pattern of 50 topographical spectral variables brought about correct group classification of 49 out of 50 probands. Results suggest that more complex statistical paradigms that take advantage of all available parameters add to an integrative explanation of psychophysiological mechanisms in mental illness.

Acute Disease↗
PubMed1990

Efficacy and safety of moclobemide compared with imipramine in the treatment of major depressive disorder. Double-blind multicenter study, Austria.

In a double-blind, 4-week, prospective, randomized multicenter (17 centers) study we checked on the efficacy, tolerability and safety of moclobemide (300-600 mg/d) compared to imipramine (100-200 mg/d) in parallel groups of patients with a Major Depressive Episode (DSM III). The mean % reduction of the HAMD at the end of treatment was 51.7 in the moclobemide group and 52.1 in the imipramine group. The percentage of patients in whom efficacy was globally judged as "good" or "very good" was 62% in the moclobemide group and 60% in the imipramine group. There was no statistically significant difference in the efficacy in both groups but in some factors there was a trend for a better amelioration favoring moclobemide. The final overall physician's judgement of tolerability was "good" or "very good" in 83% of moclobemide patients and in 74% of imipramine patients. Adverse events were reported or observed in 56% of moclobemide patients and in 69% of imipramine patients. The number of mild, moderate and severe adverse events was higher in the imipramine group with a total of 286 versus 189. There was a statistically high significant difference considering the tolerability favoring moclobemide again. In this project the basic goal to find a substance with at least the same efficacy but a much better tolerability for sure got fulfilled.

Adolescent↗
PubMed1990

A double-blind multicentre study comparing remoxipride, controlled release formulation, with haloperidol in schizophrenia.

A double-blind multicentre study was undertaken to compare the efficacy and safety of remoxipride in a controlled release (CR) formulation given once daily with haloperidol twice daily in patients with schizophrenic illness. In total, 114 patients were included. All were diagnosed as schizophrenic or schizophreniform according to DSM-III. Their mean daily dose of remoxipride CR during the last week of treatment was 385 mg. In the haloperidol group the corresponding dose was 17 mg per day. The intended study period was 4 weeks with at least a one-day washout. No significant differences were found between treatments regarding efficacy variables. The median total Brief Psychiatric Rating Scale (BPRS) score was 40 in the remoxipride CR group at start of treatment and 21 at last valid rating. For the haloperidol group the corresponding figures were 40 and 22. Treatment-emergent extrapyramidal symptoms (Simpson and Angus rating) occurred statistically significantly more frequently and were more severe during haloperidol than during remoxipride CR treatment despite a statistically significantly higher concurrent use of anticholinergic drugs in the haloperidol group.

Acute Disease↗
PubMed1985

A study of cerebral blood flow and metabolism in epileptic psychosis using positron emission tomography and oxygen.

Data are presented on four groups using positron tomography and 15 O inhalation. Compared to age-matched volunteer controls, epileptic patients show regions of low blood flow and hypometabolism as found in previous studies. Epileptic psychotic and non-psychotic patients have been compared, and the main differences noted were lower rOER in the psychotic group, especially in frontal, temporal and basal ganglia regions. When a group of psychotic patients receiving neuroleptic drugs was compared to those free of these medications the rOER was higher in the treated sample, and the rCBF fell, significantly in some areas. These data are discussed in the light of other reports of positron tomography in psychosis.

Antipsychotic Agents↗
PubMed1984

Epilepsy and its prejudice. Teachers' knowledge and opinions: are they a response to psychopathological phenomena?

150 teachers, 75 from a group of basic schools and 75 from a group of schools on an advanced level were asked to respond to a questionnaire consisting of 194 items in order to find out about their actual state of knowledge, opinions and prejudices against epileptics. 45 stereotype statements had to be rated for 'epilepsy', 'insanity', and 'heart disease'. A ranking order of 6 disorders--'insanity', 'depression', 'epilepsy', 'heart disease', 'amputation of a leg', and 'diabetes mellitus' had to be established. Teachers' knowledge of epilepsy proved to be somewhat diffuse but in good keeping with reality and they showed an interest in more information and research. Some of their prejudices could be attributed to old ideologies while the acquaintance with epileptics enhanced their knowledge of their real needs. Teachers' confusions went along with the controversies in medical research.

Adult↗
PubMed1982

Computertomography in subarachnoid haemorrhage and aneurysm.

50 patients with SAH and an aneurysm were investigated by CT and angiography. In the 59 patients 67 aneurysms were found. The mean interval between SAH and CT was 8 days, between SAH and angiography II days. Blood in the CSF space was visualized up to the 9th day in the patients and 67% of those investigated showed blood in the CSF-space in the CT. In 31% of the patients an aneurysm, in 29% an intracerebral haemorrhage and in 19% a recent infarct was found. A hydrocephalus was seen in 13% of the patients. Of 12 patients with recent infarcts 8 showed vasospasm which correlated in time and location with the infarct.

Adolescent↗