Biomedical subjects

P Schlattmann

Publications and source records attributed to P Schlattmann.

At least 19 recordsLinked to original sources

PubMed2006

Cerebrovascular reactivity in depressed patients without vascular risk factors.

INTRODUCTION: Cerebrovascular reactivity (CVR) seems to be gaining importance as a prognostic factor for stroke risk. CVR reflects the compensatory dilatory capacity of cerebral arterioles to a dilatory stimulus; this mechanism plays an important role in maintaining a constant cerebral blood flow. Evaluating factors that influence CVR will help prevention or early detection of cerebrovascular disease (CVD). In this study we aimed to measure the CVR in vascular-risk free depressed individuals so as to evaluate the effect depression has on CVR and hence its role as a stroke risk factor. METHODS: Using acetazolamid (ACZ) stimulation, CVR was assessed with a transcranial Doppler ultrasound in 25 non-smoking depressed patients (average age: 48.48 +/- 14.40) and in 25 healthy non-smoking controls (average age: 46.76 +/- 13.69) by calculating the difference between the maximal mean blood flow velocity at baseline and the maximal mean blood flow velocity after ACZ stimulation. RESULTS: Basal Cerebral Blood flow in Patients was 50.6 cm/s (SD: 11.6) versus controls 52.80 cm/s (SD: 12.70) whereas after stimulation maximal blood flow velocity was 72.64 cm/s (SD: 15.75) in patients versus 80.20 cm/s (SD: 18.43) in controls. In an analysis of covariance we found that cerebrovascular reactivity was significantly reduced in the vascular-risk free depressed sample. Age had a significant influence whereas gender did not. DISCUSSION: Major Depression appears to decrease cerebrovascular reactivity supporting the idea of increased risk for stroke in depressed patients. The mechanisms leading to this phenomenon and its subtle subgroup differences should be further investigated.

Acetazolamide↗

PubMed2006

A randomised, controlled study on the effects of a short-term endurance training programme in patients with major depression.

OBJECTIVE: To evaluate the short-term effects of exercise in patients with major depression. DESIGN: Prospective, randomised, controlled study. SETTING: A university hospital. PATIENTS: A consecutive series of 38 inpatients with a major depression episode undergoing standard clinical antidepressant drug treatment. INTERVENTIONS: Patients were randomly assigned to an exercise (walking, n = 20) or placebo (low-intensity stretching and relaxation exercises, n = 18) group. Training was carried out for 10 days. MAIN OUTCOME MEASUREMENTS: Severity of depression assessed with the Bech-Rafaelsen Melancholy Scale (BRMS) and the Center for Epidemiologic Studies Depression scale (CES-D). RESULTS: After 10 days, reduction of depression scores in the exercise group was significantly larger than in the placebo group (BRMS: 36% v 18%; CES-D: 41% v 21%; p for both = 0.01); the proportion of patients with a clinical response (reduction in the BRMS scores by more than six points) was also larger for the exercise group (65% v 22%, p<0.01). CONCLUSIONS: Endurance exercise may help to achieve substantial improvement in the mood of selected patients with major depression in a short time.

Adult↗

PubMed2006

Cerebrovascular reactivity over time course in healthy subjects.

INTRODUCTION: Cerebrovascular reactivity (CVR) reflects the compensatory dilatory capacity of cerebral arterioles to a dilatory stimulus and is an important mechanism for maintaining constant cerebral blood flow. Many pathological conditions are associated with an impaired CVR thus contributing to a higher risk of cerebrovascular disease. Since an impaired CVR might contribute to a cerebrovascular disease if it lasts for a longer period of time, it is of importance to know what the time-course of CVR might be under healthy conditions. METHODS: We investigated CVR in 33 healthy subjects on baseline and on follow-up after 1 to 3 years. CVR was determined by calculating the difference between maximal blood flow velocity after stimulation with acetazolamide and during rest. Blood flow velocities were measured by transcranial Doppler ultrasound. RESULTS: CVR did not differ significantly in a group of healthy persons when reevaluated after 1 to 3 years. Possible influencing factors like age, gender, interval between testing, and smoking did not show a significant influence. DISCUSSION: This is the first study to investigate within-subject-differences in healthy subjects. CVR seems to remain constant under healthy conditions. Even this short period of life-span is of importance because an altered CVR can improve under treatment within weeks. Nevertheless further studies should follow-up longer periods of time.

Adult↗

PubMed2006

Bleeding complications after endovascular therapy of cerebral arteriovenous malformations.

BACKGROUND AND PURPOSE: Intracerebral hemorrhages after embolization of arteriovenous malformations (AVMs) are the most dreaded complications of this well-established therapy. Apart from the known risk factors, our center noticed a high incidence of complications during postinterventional monitoring in medical intensive care units (ICUs) and stroke units. MATERIALS AND METHODS: We report 125 consecutive interventions performed on 66 patients by using flow-dependent microcatheters and n-butyl cyanoacrylate as the embolic agent. Postinterventional intensive care monitoring was performed in an interdisciplinary operative ICU, a stroke unit, or a medical ICU. Patients were compared with regard to bleeding complications, AVM morphology, embolization result, postinterventional monitoring, and demographic factors. RESULTS: Intracerebral hemorrhages occurred in 7 patients. Significant differences in outcome were found between 66 patients monitored in the interdisciplinary operative ICU from medical ICU or stroke unit. This was also true when adjusted for age and extent of AVM reduction by using exact logistic regression. A partial AVM reduction of >60% was a considerable risk factor for hemorrhage (odds ratio [OR] = 18.8; 95% confidence interval [CI] [1.341, not available]. Age was also an essential risk factor. An age difference of 10 years leads to an OR of 2.545 (95% CI [1.56, 7.35]). DISCUSSION: A considerable AVM reduction in one session appears to increase the risk of hemorrhage technically. This suggests a distribution of the interventions in many partial steps.

Adolescent↗

PubMed2005

Negative symptoms of schizophrenia are improved by the addition of paroxetine to neuroleptics: a double-blind placebo-controlled study.

Despite the availability of atypical antipsychotics, the treatment of negative symptoms in schizophrenia remains a challenge. This study was designed to confirm the positive effect observed in our pilot study with paroxetine as augmentation to antipsychotics in the treatment of negative symptoms in chronic schizophrenia. Twenty-nine patients with chronic schizophrenia, as defined by DSM-IV, who scored at least 20 points on the negative subscale of the Positive and Negative Syndrome Scale (PANSS) were randomized for treatment with 30 mg paroxetine or placebo in a double-blind, placebo-controlled study for 12 weeks. Ratings included the PANSS, the Hamilton Rating Scale for Depression (HAM-D) and scales for extrapyramidal side-effects. An intention-to-treat analysis was based on the 25 patients who were available for at least one follow-up assessment. The last observation carried forward principle was applied. The mean score of the negative subscale of the PANSS decreased in both groups. Using an analysis of covariance, there was a significant treatment effect with paroxetine compared to placebo with respect to negative symptoms (-4.53; 95% confidence interval -9.054 to -0.015). The mean HAM-D scores remained almost constant. The study suggests the efficacy of paroxetine with respect to the treatment of negative symptoms in chronic schizophrenia.

Adult↗

PubMed2005

Efficacy of cognitive behaviour therapy in generalized anxiety disorders. Results of a controlled clinical trial (Berlin CBT-GAD Study).

BACKGROUND: Generalized anxiety disorders (GAD) are amongst the most prevalent mental disorders. Recent studies have suggested that cognitive behaviour therapy (CBT) is an effective treatment for GAD. A controlled clinical trial was done to evaluate the efficacy of CBT treatment in outpatients with pure GAD who were treated by a therapist working in routine care. METHODS: Seventy-two outpatients, fulfilling GAD criteria according to DSM-IV, were included in the study. From this group, 36 patients (CBT-A) were randomly assigned to 25 sessions of CBT and the other 36 formed a contact control group (CCG). After the contact control period (CC period), these patients were also treated with CBT (CBT-B), allowing not only a parallel group comparison but also an A-B comparison. Therapists were licensed full-time psychologists who worked routinely in outpatient care and had a professional training in CBT. Treatment was done in accordance with a manual, and treatment conformity was controlled by several methods. RESULTS: The reduction in the score on the Hamilton Anxiety Observer Rating Scale was 6.4% (1.5 points) in the CCG, 35.4% (9.5 points) in the CBT-A and 47.3% (10.3 points) in the CBT-B. In the self-rating Spielberger State-Trait Anxiety Inventory, a reduction of 2.7% was seen in CCG, 14.6% in CBT-A, and 11.6% in CBT-B. According to the Clinical Global Impression Rating, 65.6% of patients were still at least moderately ill at the end of the CC period, while this rate was 33.4% at the end of CBT-A, or 15.7% at the end of CBT-B. All these differences between treatment and control group are statistically highly significant. The clinical improvement remained stable over a follow-up period of 8 months. CONCLUSIONS: CBT is an effective method of treatment for GAD. Differences between control and treatment group are comparable to or larger than those reported in studies on antidepressant drugs.

Adult↗

PubMed2003

Does prophylaxis-delay in bipolar disorder influence outcome? Results from a long-term study of 147 patients.

OBJECTIVE: This study investigated the impact of latency (the time between illness onset and initiation of prophylactic treatment) on the outcome of prophylaxis in bipolar disorders. METHOD: The effect of prophylaxis delay (latency) on the course of illness was assessed in 147 patients. Dependent variables were: reduction of days spent in the hospital (prior to vs. during prophylaxis), time to first recurrence, and Morbidity-Index during prophylaxis (lithium or carbamazepine). Latency and other independent variables were tested using a multivariate approach. RESULTS: Latency (9.3 years on average) had no significant effect on the subsequent response. Illness severity prior to prophylaxis, however, did predict the relative response. The course of illness during treatment could not be predicted by any one factor. CONCLUSION: The delay in initiating prophylaxis appears to have no influence on prophylaxis outcome. Instead, those whose illness was more severe were treated earlier and these patients subsequently showed a relatively greater response. If severity is not controlled for as part of the analysis, latency may be mistaken as an important predictor for response.

Adult↗

PubMed2002

An introduction to statistical concepts for the analysis of EEG data and the planning of pharmaco-EEG trials.

The use of descriptive statistics and graphics for electroencephalogram (EEG) data after initial data reduction and the application of hypothesis tests to EEG data are described. In planning pharmaco-EEG trials, some notion of statistical power and variability of effect size is necessary as they are used to calculate sample size in parallel-group clinical trials. The need for sensitivity analysis during the study planning phase is demonstrated as well. Because EEG data are highly dimensional data, an outline of methods for reducing dimensionality is provided. These concepts are demonstrated using data from patients with Alzheimer's disease and from healthy controls.

Alzheimer Disease↗

PubMed2001

Time-related cognitive deficiency in four different types of depression.

Mild cognitive impairment often occurs in depressive illness. But it is unknown whether the occurrence or severity of cognitive deficits has diagnostic specificity. It is of interest to investigate whether there are time-related differences in cognitive functions characteristic of different kinds of depressive diagnoses, and therefore whether such differences might help to distinguish between types of depressive disorder. Eighty inpatients with a DSM-IV depressive episode (unipolar, bipolar, dysthymic and schizoaffective disorder, depressive type) were assessed with a series of neuropsychological tests at the beginning and at the end of their hospital stays. A group of 62 matched healthy controls were assessed with the same series of tests at comparable intervals. The diagnostic sub-groups could not be distinguished by cognitive parameters in the time-course. At the time of admission the inpatient group had a worse performance than the control group. After a significant decrease of their mean depression score, the patients still continued to show an outcome worse than the controls. We conclude that the variation of cognitive dysfunction with time in depression seems to be a phenomenon which does not depend on the kind of depressive sub-diagnosis. The results indicate that cognitive deficits might persist longer than the period of illness, but this seems to be true for all depressive sub-diagnoses.

Adult↗

PubMed2001

Reduced event-related current density in the anterior cingulate cortex in schizophrenia.

There is good evidence from neuroanatomic postmortem and functional imaging studies that dysfunction of the anterior cingulate cortex plays a prominent role in the pathophysiology of schizophrenia. So far, no electrophysiological localization study has been performed to investigate this deficit. We investigated 18 drug-free schizophrenic patients and 25 normal subjects with an auditory choice reaction task and measured event-related activity with 19 electrodes. Estimation of the current source density distribution in Talairach space was performed with low-resolution electromagnetic tomography (LORETA). In normals, we could differentiate between an early event-related potential peak of the N1 (90-100 ms) and a later N1 peak (120-130 ms). Subsequent current-density LORETA analysis in Talairach space showed increased activity in the auditory cortex area during the first N1 peak and increased activity in the anterior cingulate gyrus during the second N1 peak. No activation difference was observed in the auditory cortex between normals and patients with schizophrenia. However, schizophrenics showed significantly less anterior cingulate gyrus activation and slowed reaction times. Our results confirm previous findings of an electrical source in the anterior cingulate and an anterior cingulate dysfunction in schizophrenics. Our data also suggest that anterior cingulate function in schizophrenics is disturbed at a relatively early time point in the information-processing stream (100-140 ms poststimulus).

Adult↗

PubMed2001

P300 and LORETA: comparison of normal subjects and schizophrenic patients.

It was the aim of the present study 1) to investigate how many cortical activity maxima of scalp-recorded P300 are detected by Low Resolution Electromagentic Tomography (LORETA) when analyses are performed with high time-resolution, 2) to see if the resulting LORETA-solution is in accordance with intracortical recordings as reported by others and 3) to compare the given pattern of cortical activation maxima in the P300-timeframe between schizophrenic patients and normal controls. Current density analysis was performed in 3-D Talairach space with high time resolution i.e. in 6 ms steps. This was done during an auditory choice reaction paradigm separately for normal subjects and schizophrenic patients with subsequent group comparisons. In normal subjects, a sequence of at least seven cortical activation maxima was found between 240-420ms poststimulus: the prefrontal cortex, anterior or medial cingulum, posterior cingulum, parietal cortex, temporal lobe, prefrontal cortex, medial or anterior cingulum. Within the given limits of spatial resolution, this sequential maxima distribution largely met the expectations from reports on intracranial recordings and functional neuroimaging studies. However, localization accuracy was higher near the central midline than at lateral aspects of the brain. Schizophrenic patients less activated their cortex in a widespread area mainly in the left hemisphere including the prefrontal cortex, posterior cingulum and the temporal lobe. From these analyses and comparsions with intracranial recordings as reported by others, it is concluded that LORETA correctly localizes P300-related cortical activity maxima on the basis of 19 electrodes except for lateral cortical aspects which is most likely an edge-phenomenon. The data further suggest that the P300-deficit in schizophrenics involves an extended cortical network of the left hemisphere at several steps in time during the information processing stream.

Adult↗

PubMed2000

Spatial distribution of in-patient service use of psychiatric patients: somatic departments versus psychiatric units.

BACKGROUND: It has long been recognized that a high proportion of psychiatric patients are admitted to emergency, medical and surgical wards. However, until now no assessment has been made of which urban general hospitals would be most appropriate for the establishment of specific psychiatric facilities. METHOD: Our study concerned Germany's second largest city, Hamburg (population 1.7 million), and involved an evaluation of psychiatric principal diagnoses in general and psychiatric hospitals. The research was based on data collected between 1988 and 1994 embracing approximately 77% of all psychiatric patients (n = 64,000) in 41 hospitals. The evaluation was carried out using the statistics programs SPSS and DismapWin. RESULTS: We established that the proportion of male patients discharged from somatic wards, mainly internal medicine, with alcohol and drug abuse as well as with neuroses and personality disorders or illegal drug abuse was surprisingly high (70%, 34% and 24% respectively). For female patients the figures were 67%, 40% and 35% respectively. A geographical analysis of spatial heterogeneity of hospitalization risks showed that general hospitals admit a disproportionately high number of patients from areas of lower social status - both male and female from the above-mentioned diagnostic categories. A rank correlation between the classification of areas based on the heterogeneity model and the social status of the areas supports this hypothesis, at least for males. CONCLUSION: Our findings lead us to the conclusion that the establishment of new psychiatric services should focus on internal wards in hospitals located in areas of low social status.

Adult↗

PubMed2000

Ventilatory capacity and risk for dementia.

BACKGROUND: Previous studies have found a relationship between single indicators of ventilatory capacity and measures of cognitive function, but have not addressed dementia specifically. This study examined the relationship between different indicators of ventilatory capacity and dementia, diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, controlling for important confounding factors. METHODS: Cross-sectional data on participants (n = 437) of the Berlin Aging Study (BASE), which are representative of former West Berlin's living population aged 70 years and older, were analyzed. Ventilatory capacity was measured by spirometry as peak expiratory flow rate (PEF-R), forced expiratory volume in 1 second (FEV-1), maximal expiratory flow at 50% of forced vital capacity (MEF50%FVC), and maximal expiratory flow at 25% of forced vital capacity (MEF25%FVC). Odds ratios (OR) for dementia associated with ventilatory capacity were obtained by logistic regression, adjusting for age, gender, education, ApoE4 status, chronic obstructive pulmonary disease, smoking, heart failure, visual and auditory functioning, grip strength, and former physical activity. RESULTS: Separate analyses for PEF-R, FEV-1, MEF50%FVC, and MEF25%FVC revealed significantly increased odds for dementia among subjects in the lowest compared with the best functioning group in ventilatory testing. The OR associated with PEF-R > or = 2 l/s was found to be 20.4 (confidence interval [CI] 5.1-82.7). For FEV-1, MEF50%FVC, and MEF25%FVC ORs of 7.5 (CI 2.1-27.9), 4.3 (CI 1.5-12.5), and 4.7 (CI 1.3-17) were obtained, respectively. CONCLUSIONS: Ventilatory capacity, measured by spirometry in a representative sample of very elderly people, is cross-sectionally related to dementia. Taking evidence from longitudinal studies into account, this result suggests that decreased respiratory function may increase the risk for dementia, independent from already known risk factors.

Aged↗

PubMed2000

Inequity in the hospital care of patients with alcoholism and medication addiction.

In a psychiatric/ecological study, the authors investigated which aspects of a town district would provide an explanation to the fact that alcoholics are treated above average in addiction-psychiatric wards in a given city district, while in other districts treatment is carried out in internal medical wards. The research was based on data collected between 1988 and 1994 from approximately 77% of all patients suffering from alcohol and legal drug abuse (n = 15,473) in 41 hospitals in Hamburg. It was established that in somatic departments, mainly internal medicine, 70% of male and 67% of female patients were admitted for alcohol and legal drug abuse. The results of a geographical analysis of hospitalization risks showed that the addiction-psychiatric facilities of psychiatric wards are mainly utilized by inhabitants from nearby districts. Risks of above-average hospitalization for alcoholics and legal drug abusers in internal wards, as well as insufficient addiction-psychiatric care, are to be expected in town districts where a shortage of psychiatrists exists, and where the unemployment rate is high. In these crucial areas, addiction-specific facilities, such as qualified programs for detoxication or techniques for short intervention, should be established within the framework of an addiction-specific liaison service in general hospitals.

Alcoholism↗

PubMed1999

Geographical analysis of the risk of psychiatric hospitalization in Hamburg from 1988 - 1994.

The analysis of the geographical distribution of hospital cases is obviously important for the purpose of planning hospital services, but it is of even greater significance in the planning of psychiatric services. This concern motivated our seven-year-long study, which examined hospitalization risks among various categories of psychiatric disorders in the major German city of Hamburg. Our database encompassed 77% (n = 64,000) of all psychiatric admissions in a total of 41 hospitals, most of which are general hospitals. In order to carry out the geographical analysis we employed a new statistical method based on a mixture distribution model. According to our findings, the strongest indications of an increased frequency were among male cases of schizophrenia, drug abuse and organic psychoses, and female cases of neurotic disorders, personality disorders, drug abuse and schizophrenia. We found that some areas are exposed to a risk of hospitalization for these diagnostic categories which is more than 50% above the reference. Contrary to other authors we did not identify an increased frequency of admission concentrated in the inner-city area for any of the diagnostic groups. The risk of hospitalization for schizophrenics was almost entirely associated with the close proximity of psychiatric units, while the risks for neuroses and personality disorders, as well as alcohol and drug abuse, appeared to be concentrated in areas of low social status. However, a statistically relevant correlation between an increased risk of hospitalization and low social status could be determined only for drug abuse and alcoholism. In the end, we did identify two areas in which there was an increased risk of hospitalization for several diagnostic groups, and this information will undoubtedly facilitate the planning of hospital and psychiatric services. The fact that our findings deviate to some extent from other authors - especially with respect to neuroses and personality disorders, but also to addiction - can be attributed to the inclusion of psychiatric cases from general hospitals in our geographic analysis.

Adolescent↗

PubMed1998

On pineal calcification and its relation to subjective sleep perception: a hypothesis-driven pilot study.

We classified the degree of pineal calcification (DOC) into seven groups using cranial Computer Tomography (cCT) and then correlated pineal DOC to chronic subjective sleep-related disturbances as measured by a sleep questionnaire in 36 patients. Analysed by logistic regression models, age and sex were not, but higher pineal DOC was significantly associated with the presence of daytime tiredness (OR = 4.15, 95% CI: 1.63, 10.54) and sleep disturbance (OR = 1.74, 95% CI: 1.10, 2.74). This study provides initial confirmation of the hypothesis that the increasing degree of pineal calcification (DOC) might indicate a decrease of melatonin production, which consecutively might lead to a disturbed circadian rhythmicity in the sleep-wake cycle, with the principal symptom being daytime tiredness.

Adult↗

PubMed1998

Age and dementia effect on neuropsychological test performance in very old age--influence of risk factors for dementia.

In old age a large part of the variance in cognitive performance in population samples is explained by normal aging; in addition many subjects over 80 years are demented and therefore dementia also explains a part of cognitive variability. The question is whether the different factors for dementia (such as ApoE4, external atrophy parameter of the cranial computer tomography [cCT], education, sex or serum zinc level) influence the relation between age or dementia and Mini Mental State (MMSE) performance. In an epidemiological study data were analyzed of N = 239 subjects for the above factors. Most statistically significant variables of the MMSE do not change the amount of the partial correlation coefficient between the parameters age or dementia and MMSE. The external atrophy, however, diminishes the magnitude of the partial correlation between age and MMSE. In contrast the dementia-MMSE relation is unchanged. This points to a generally similar factor structure of cognitive aging and dementia in old age, but differences exist with respect to the importance of the external atrophy parameter of the brain. Most factors investigated explain separate parts of variance of cognitive performance in old age.

Adult↗

PubMed1998

Recent developments in computer-assisted analysis of mixtures.

This paper reviews recent developments in the area of computer-assisted analysis of mixture distributions (C.A.MAN). Given a biometric situation of interest in which, under homogeneity assumptions, a certain parametric density occurs, such as the Poisson, the binomial, the geometric, the normal, and so forth, then it is argued that this situation can easily be enlarged to allow a variation of the scalar parameter in the population. This situation is called unobserved heterogeneity. This naturally leads to a specific form of nonparametric mixture distribution that can then be assumed to be the standard model in the biometric application of interest (since it also incorporates the homogeneous situations as a special case). Besides developments in theory and algorithms, the work focuses on developments in biometric applications such as meta-analysis, fertility studies, estimation of prevalence under clustering, and estimation of the distribution function of survival time under interval censoring. The approach is nonparametric for the mixing distribution, including leaving the number of components (subpopulations) of the mixing distribution unknown.

Animals↗