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Biomedical subjects

Ralf Pukrop

Publications and source records attributed to Ralf Pukrop.

At least 19 recordsLinked to original sources
PubMed2006

Neurophysiology of nocturnal enuresis: evoked potentials and prepulse inhibition of the startle reflex.

Nocturnal enuresis is a genetically determined maturational disorder of the central nervous system. Lack of arousal and an inhibition deficit of the micturition reflex have been found as the main dysfunctions leading to wetting during sleep. Both are mediated by nuclei in the brainstem. Therefore, evoked potentials (brainstem auditory evoked potential [BAEP], visual evoked potential [VEP], event-related late acoustic-evoked potential [P300]), and the prepulse inhibition (PPI) of the startle reflex were assessed to further evaluate the brainstem deficit compared with cortical function. Thirty-seven children with nocturnal enuresis, aged 8 years to 14 years 8 months (mean age 10y 7mo [SD 1y 10mo]; 27 males, 10 females) were compared with 40 controls (mean age 10y 7mo [SD 1y 6mo]; 17 males, 23 females). Left interpeak latencies I-III and I-V of the BAEP were increased in children with nocturnal enuresis. VEP measures did not differ between patients and controls. However, children with a positive family history of enuresis showed a shorter latency towards N75 and P100 than children without such a family history. P300 and PPI measures did not differ. We conclude that this strongly supports the postulation of a maturational deficit of the brainstem in nocturnal enuretic children. The increased interpeak latencies I-III and I-V of the BAEP support the hypothesis of an arousal deficit mediated by delayed maturation of brainstem function. Differences in VEP latencies might point towards functional cortical differences in children with a family history of nocturnal enuresis.

Arousal↗
PubMed2006

Neuromotor development in nocturnal enuresis.

In children with nocturnal enuresis, a higher rate of minor neurological dysfunction has been found. The aim of this study was to assess timed performance (a measure of motor performance speed) and associated movements using a standardized and reliable instrument. The motor function of 37 children with nocturnal enuresis (27 males, 10 females; mean age 10y 7mo [SD 1y 10mo]; age range 8y-14y 8mo) and 40 comparison children without enuresis (17 males, 23 females; mean age 10y 7mo [SD 1y 6mo]; age range 8y-14y 8mo) was assessed using the Zurich Neuromotor Assessment. Children with nocturnal enuresis showed a slower motor performance than comparison children, particularly for repetitive hand and finger movements. This study provides evidence for a maturational deficit in motor performance in children with nocturnal enuresis. In addition to a maturational deficit of the brainstem, it is proposed that there is a possible maturational deficit of the motor cortex circuitry and related cortical areas in children with nocturnal enuresis.

Child↗
PubMed2006

Neurocognitive functioning in subjects at risk for a first episode of psychosis compared with first- and multiple-episode schizophrenia.

Evidence from neurobiological studies suggests that schizophrenia arises from an early abnormality in brain development and possibly further progressive developmental mechanisms. Despite a delay between the acquisition of neuropathology and the triggering of psychosis, neurobiological susceptibility is likely to be expressed subclinically by biobehavioral markers in the premorbid stage. The exploratory study aims at identifying potential neurocognitive risk factors and investigating the unfolding of the illness within a cross-sectional design by comparing neurocognitive profiles in 179 healthy controls, 38 clinically identified subjects in an early initial prodromal state (EIPS) for psychosis, 90 subjects in a late initial prodromal state (LIPS), 86 first-episode patients with schizophrenia, and 88 multiple-episode patients. Subjects at risk were substantially impaired in verbal executive and verbal memory functions. Compared to EIPS subjects, LIPS subjects demonstrated additional attentional deficits. Both EIPS and LIPS subjects were superior to first-episode patients who presented a generalized neuropsychological deficit profile, and to multiple-episode patients who showed evidence for further decline. Although results were influenced by general intellectual abilities and demographic and clinical characteristics, they could not account for total group differences. Results support a neurodevelopmental model of psychosis with further progressive mechanisms and are consistent with a primary involvement of left frontotemporal networks in the prodromal phase.

Adult↗
PubMed2006

Alexithymia in obsessive-compulsive disorder - results from a family study.

BACKGROUND: Previous studies have suggested an association between alexithymia and obsessive-compulsive disorder (OCD). However, it is unclear to which extent alexithymic traits in OCD patients reflect familial deficits in cognitively processing and communicating feelings that are also present in their first-degree relatives. This study investigates the hypotheses of an elevated level of alexithymia in subjects with OCD and their first-degree relatives compared to controls and their first-degree relatives. METHODS: 82 cases with OCD and 169 first-degree relatives were compared to 76 controls and 144 first-degree relatives from a German family study on OCD (GENOS). All subjects completed the 20-item Toronto Alexithymia Scale (TAS-20). Direct or family informant interviews were carried out with the German version of the Schedule for Affective Disorders and Schizophrenia - lifetime version for anxiety disorders (DSM-IV). RESULTS: OCD was associated with significantly higher scores of alexithymia. However, first-degree relatives of OCD cases and of controls did not differ in TAS-20 scores. In linear regression analyses, the TAS-20 total score showed significant intrafamilial associations within the families of control subjects but not within families of OCD cases. CONCLUSION: OCD is a severe mental disorder that is associated independently from other current comorbid axis I disorders with deficits in identifying and expressing feelings. However, alexithymia does not represent a familial risk factor for OCD.

Adult↗
PubMed2006

Familiality of obsessive-compulsive disorder in nonclinical and clinical subjects.

OBJECTIVE: Studies of the familiality of obsessive-compulsive disorder (OCD) have yielded inconsistent results. This study compared the familial aggregation of OCD in first-degree relatives of community subjects with never-treated OCD, outpatients with OCD, and comparison subjects. METHOD: Fifteen persons from the community with untreated OCD were matched on age and interview type (direct or through family informants) with 90 OCD patients from four treatment facilities and 70 comparison subjects. Direct or indirect interviews using the German-language version of the Schedule for Affective Disorders and Schizophrenia-Lifetime Version for Anxiety Disorders (DSM-IV) were obtained from 58, 285, and 247 first-degree relatives, respectively, of the three groups. The rate of OCD in case versus comparison relatives was assessed with chi-square tests, and odds ratios were calculated for risk estimation. Cox proportional hazards analysis was used to estimate the age-related risk of relatives of being affected by OCD. RESULTS: Cox proportional hazards analyses revealed a 6.2-fold higher risk (hazard ratio) for relatives of all OCD cases for definite OCD and a 2.2-fold higher risk for subclinical OCD compared with relatives of comparison subjects. For relatives of community subjects with OCD, the risk for definite OCD (10.3% versus 5.6%) was 1.6, and the risk for subclinical OCD (15.4% versus 4.1%) was 3.4 compared with relatives of OCD patients from treatment sites. CONCLUSIONS: These results from the first controlled European family study of OCD confirm earlier U.S. data on the familiality of OCD in patients recruited from treatment facilities. The finding of a comparable familial aggregation of definite OCD and a higher familial aggregation of subclinical OCD in relatives of never-treated persons with OCD from the community strongly supports the impact of familial-genetic factors in OCD.

Ambulatory Care↗
PubMed2005

Subjective quality of life in subjects at risk for a first episode of psychosis: a comparison with first episode schizophrenia patients and healthy controls.

The concept of quality of life (QoL) is of growing relevance in schizophrenia research. However, there is to date no information on subjective QoL in subjects at risk for a first episode of psychosis in comparison to first episode schizophrenia patients (FE) or healthy controls (HC). Therefore 45 subjects in a putatively early initial prodromal state (EIPS), 40 FE and 45 HC were assessed on demographics, symptoms and subjective QoL as measured by the Modular System for Quality of Life. Results indicated that in most areas HC experienced the highest QoL scores followed in hierarchical order by EIPS and FE. EIPS and FE experienced significantly lower QoL than HC in 5 and 6 of 7 QoL domains. EIPS experienced the lowest ratings in affective QoL. Thus the data demonstrates that subjective QoL in subjects at risk for a first episode of psychosis is substantially reduced when compared with HC and suggests that subjective QoL is already compromised prior to the onset of first positive schizophrenia symptoms. These findings support the notion that subjects at risk for a first episode of psychosis constitute a clinical population for which further service and intervention research is indicated.

Adolescent↗
PubMed2005

Impaired mismatch negativity generation in prodromal subjects and patients with schizophrenia.

BACKGROUND: Mismatch negativity (MMN) specifically the response to tone duration deviants has consistently been shown to be reduced in schizophrenia suggesting dysfunction in auditory sensory memory. As part of a multidimensional approach to the early recognition of psychosis, MMN was investigated as a possible risk factor for later development of psychosis in subjects with a prodromal syndrome. Forty-three prodromal subjects, 31 neuroleptic-free inpatients with schizophrenia and 33 healthy controls were studied. A prodromal state was defined by a cluster 'Cognitive Disturbances' as defined by the 'Bonn Scale for the Assessment of Basic Symptoms' (BSABS), which was found highly predictive of first-episode schizophrenia. To elicit MMN, a three-tone auditory oddball paradigm with 10% 'duration deviants' and 10% 'frequency deviants' was used. RESULTS: MMN amplitudes to tone duration deviants were significantly reduced in the patients with schizophrenia compared to controls. The putatively prodromal subjects also showed a slight, though non-significant reduction of the MMN amplitude that was intermediate between normal controls and patients with schizophrenia, and with a larger within-group variance. CONCLUSION: These results support the view that abnormalities in temporal processing are particularly pronounced in patients with schizophrenia. Prodromal subjects are a heterogeneous group with regard to outcome and time until transition to a first psychotic episode. Follow-up of these putatively prodromal subjects will show whether MMN amplitudes further reduce over time in those developing psychosis and if a reduction is state-dependent.

Acoustic Stimulation↗
PubMed2005

Neural correlates of visuo-spatial attention during an antisaccade task in schizophrenia: an ERP study.

The authors investigated the role of visuo-spatial attention in an antisaccade task using event-related potentials (ERPs) in schizophrenia patients compared to healthy controls. ERPs between 80-130 ms (P100) after stimulus onset showed differences between pro- and antisaccades only for controls and can be related to the suppression of irrelevant stimulus features. Between 150-180 ms (N100), a larger amplitude for anti-compared to prosaccades over centroparietal electrodes showed that processes of visuo-spatial attention seem to be engaged in performance of the antisaccade task. Left temporo-occipitally, this activity was only evident in schizophrenia patients, possibly reflecting additional neuronal recruitment in order to perform the antisaccade task successfully.

Adult↗
PubMed2005

Changing views about personality disorders: Comment about the prospective studies CIC, CLPS, and MSAD.

Three large-scale prospective studies (Children in the Community Study [CIC; Cohen, Crawford, Johnson, & Kasen, this issue], Collaborative Longitudinal Personality Disorders Study [CLPS; Skodol et al., this issue], and the McLean Study of Adult Development [MSAD; Zanarini, Frankenburg, Hennen, Reich, & Silk, this issue]) are discussed with respect to the following issues: shared and complementary features of the study designs, evidence for stable and changing personality disorder features, methodological issues (reliability, stability, and invariance), the relationship between Axis I and II disorders, and dimensional versus categorical representations of personality disorders.

Humans↗
PubMed2003

Dimensions of working memory dysfunction in schizophrenia.

The aim of this study was to investigate the underlying structure of eight working memory tests used to assess prefrontal dysfunction in schizophrenia research [Letter-Number Span (LNS), Digit-Symbol Test (DST), Trail-Making Test B (TMT-B), Delayed Response Task (DRT) for spatial working memory, Subject Ordered Pointing Task (SOPT), Dual Tasking (DUAL), Continuous Performance Test (CPT)-Identical Pairs, Wisconsin Card Sorting Test (WCST)]. Sixty-six patients with schizophrenia showed significant working memory performance deficits in all tests when compared with 45 healthy controls. Performance was not systematically related to psychopathology. When differences in IQ were controlled, working memory deficits remained stable except in the WCST. Principal components analyses yielded three components for healthy controls: a comparator function of the central executive defined by a comparison of working memory content with information from the environment, an allocation of attentional resources function, and a maximum storage capacity function. The comparator and maximum storage functions could be replicated in the schizophrenia sample. However, the allocation function did not emerge as an independent component and was replaced by a component defined by the WCST. These findings suggest that working memory is not a unitary concept but rather should be conceptually differentiated as functions of transient storage/active rehearsal capacity and central executive manipulation supporting a previous suggestion proposed by Perry et al. [Schizophr. Bull. 27 (2001) 157].

Adult↗
PubMed2003

Reliability and validity of Quality of Life assessed by the Short-Form 36 and the Modular System for Quality of Life in patients with schizophrenia and patients with depression.

Reliability and validity of the Quality of Life (QoL) construct were investigated in healthy controls (N=346), patients with depression (N=114) and patients with schizophrenia (N=91) using two different QoL instruments: the Short-Form 36 (SF-36), a well-established generic instrument measuring eight dimensions; and the Modular System for Quality of Life (MSQoL), a recently developed instrument measuring seven core dimensions and four specific modules (objective data, partnership, family, occupation). The MSQoL and the SF-36 were administered at three intervals (hospital admission, discharge and 4-month follow-up). Reliability, group profiles (clinical specificity), responsiveness, discriminant validity (with regard to sociodemographic, psychopathological, clinical and state variables) and convergent validity were tested. At admission, patients with depression had the lowest QoL level, patients with schizophrenia had an intermediate level, and controls had the highest QoL level. At discharge and follow-up, the two patient groups did not differ from each other, but still had lower levels than controls. Both patient groups improved significantly in QoL from admission to discharge. This improvement was confounded by improvement in depressive symptoms, but not in positive or negative symptoms. Current mood state influenced QoL assessments in all three samples substantially. In conclusion, QoL can be measured reliably and with sufficient responsiveness by the MSQoL and the SF-36 in psychiatric and non-clinical populations, although discriminant validity with regard to depression and current mood is questionable.

Adult↗
PubMed2003

Outcome in psychogenic nonepileptic seizures: 1 to 10-year follow-up in 164 patients.

Our knowledge of longer term outcome in psychogenic nonepileptic seizures (PNESs) patients is limited; we know less still about factors predicting prognosis. This study was intended to describe outcome in a large cohort and to identify predictive clinical and psychological factors to generate new ideas for treatment. One hundred sixty-four adult patients with PNESs (66.7%) responded to outcome, personality, and psychosymptomatology questionnaires (Dimensional Assessment of Personality Pathology-Basic Questionnaire [DAPP-BQ], Dissociative Experiences Scale, and Screening Test for Somatoform Symptoms) a mean of 11.9 years after manifestation and 4.1 years after diagnosis of PNES. Additional clinical data were retrieved from hospital records. The responses showed that 71.2% of patients continued to have seizures and 56.4% were dependent on social security. Dependence increased with follow-up. Outcome was better in patients with greater educational attainments, younger onset and diagnosis, attacks with less dramatic features, fewer additional somatoform complaints, and lower dissociation scores. Better outcome was associated with lower scores of the higher order personality dimensions "inhibitedness," "emotional dysregulation," and "compulsivity" but not "dissocial behavior" (DAPP-BQ). Outcome in PNESs is poor but variable. Clinical and personality factors can be used to provide an individualized prognosis. By generating a patient-specific profile, they show particular maladaptive traits or tendencies that can identify goals for psychological therapy.

Adult↗
PubMed2003

Determinants of subjective quality of life in post acute patients with schizophrenia.

Although Quality of Life (QoL) is of growing interest in schizophrenia research, little is known about putative causal determinants of this multidimensional construct. The present study explored the utility of objective indicators, psychopathological symptoms and psychosocial concepts drawn from empirical findings in community samples and the vulnerability-stress-coping model of schizophrenia for predicting general subjective QoL in post acute patients with schizophrenia. The analyses were based on cross-sectional data from 66 post acute patients with schizophrenia. The relationships between QoL and possible determinants were investigated using correlational analysis, regression analysis and structural equation techniques. As a result no significant relationships between objective indicators and general QoL were found. The strongest significant determinants were depressive symptoms and the psychosocial concepts of negative coping, perceived social support and self-efficacy. The empirical causal modelling results indicated that depression led to a direct negative impact upon QoL, whereas the other determinants had direct negative or positive effects on depression and affected QoL indirectly. One could conclude that to enhance patients' QoL, improvements in depressive symptoms, negative coping style, social support and self-efficacy seem to be most effective.

Activities of Daily Living↗
PubMed2003

Clinical significance of recurrent psychogenic nonepileptic seizure status.

To explore the clinical significance of a history of recurrent psychogenic nonepileptic seizure status (PNES-status), this study describes the frequency of PNES-status in 85 consecutive PNES patients and examines whether there are relevant differences between patients with a history of recurrent PNES-status and other PNES-patients. PNES patients were also compared with 64 patients with epilepsy. Data were extracted from hospital records and a postal questionnaire (Dimensional Assessment of Personality Pathology-Basic Questionnaire; Screening for Somatoform Symptoms; Dissociative Experience Scale). Of the PNES-patients, 77.6% reported at least one seizure > 30 minutes (PNES-status), 27 % admission to intensive care with status. 38.8% reported recurrent hospital admissions with status (PNES-status group), the remaining patients served as PNES-controls. The only clinical difference between the two PNES groups was that status patients were younger than PNES-controls (mean age 20.3 vs. 30.3 years, p = 0.001). Our results suggest that PNES status is common and often unrecognised. There were no substantial psychometric differences between patients with recurrent PNES-status and other PNES patients although both PNES-groups had more abnormal somatisation, dissociation and personality scores than patients with epilepsy.

Adolescent↗
PubMed2003

Somatization, dissociation and general psychopathology in patients with psychogenic non-epileptic seizures.

The etiology of psychogenic non-epileptic seizures (PNES) remains uncertain. Previous studies have shown that PNES patients are characterized by high levels of somatization, dissociation and general psychopathology but a correlation of measures of these features and PNES severity or outcome has never been demonstrated, although this would strengthen a possible etiological link. This study measured somatization (Screening Test for Somatoform Symptoms-2), dissociation (Dissociative Experience Scale, DES), and general psychopathology (Symptom Checklist-90-Revised, SCL-90) in 98 patients with PNES and 63 patients with epilepsy. All mean scores were raised in the PNES compared to the epilepsy group. However, only measures of somatization and general psychopathology discriminated between patients with PNES and epilepsy in a logistic regression model (even when patient gender was controlled for). In PNES patients, high somatization scores correlated with poor outcome and greater seizure severity even after correction was made for dissociation and psychopathology. Dissociation and psychopathology scores were not independently associated with outcome or severity. The results suggest that, as a group, patients with PNES are best characterized by their tendency to express psychosocial distress by producing unexplained somatic symptoms which are brought to medical attention. Although dissociation may be relevant in some individuals it does not appear to be an independent factor across the whole PNES patient group.

Adult↗
PubMed2003

Effects of psychosocial interventions on quality of life in adult cancer patients: meta analysis of 37 published controlled outcome studies.

The present meta analysis summarized the results of 37 published, controlled studies that investigated the effectiveness of psychosocial interventions on quality of life (QoL) in adult cancer patients. The overall effect size of psychosocial interventions and the effect of potential moderating variables such as type and duration of intervention, sociodemographic and clinical parameters, characteristics of QoL measurement, and methodological quality of the selected studies were calculated using a meta analysis model suggested by Hunter and Schmidt. The overall effect size was 0.31 (correlation equivalent delta) which corresponds to a standardized mean difference of d=0.65 (N=3120 cancer patients). The most important moderating variable was duration of psychosocial intervention with durations of more than 12 weeks being significantly more effective than interventions of shorter duration. The meta analytical findings support the usefulness of psychosocial interventions for improving QoL in adult cancer patients.

Adaptation, Psychological↗
PubMed2002

Subjective and objective neuropsychological abnormalities in a psychosis prodrome clinic.

BACKGROUND: Predicting transitions to psychosis is difficult. Neuropsychology might facilitate predictions. AIMS: To report preliminary data on self-perceived and objectively measurable neurocognition in prodromal patients of the first German early recognition centre. METHOD: Subjective neuropsychological disturbances were assessed in 51 patients with potentially prodromal symptoms of schizophrenia. Initial neurocognitive functioning was compared with matched normals and patients with schizophrenia. RESULTS: Self-perceived deficits mostly concerned perception, cognition and stress reactivity. Five transitions happened during the 15-month follow-up. Recently emerging or intensifying deficits were to some extent predictive of transition. Persons at risk performed worse than controls on objectively measured verbal capacity, attention and memory functions. CONCLUSIONS: Neuropsychological deficits, either self-perceived or objectively measured, characterise persons at risk for schizophrenia and may contribute to predicting transitions.

Adolescent↗