Bernhard Blanz

fMRI during word processing in dyslexic and normal reading children.

The present study addresses phonological processing in children with developmental dyslexia. Following the hypothesis of a core deficit of assembled phonology in dyslexia a set of hierarchically structured tasks was applied that specifically control for different kinds of phonological coding (assembled versus addressed phonological strategies). Seventeen developmental dyslexics and 17 normal reading children were scanned during four different tasks: (1) passive viewing of letter strings (control condition), (2) passive reading of non-words, (3) passive reading of legal words, and (4) a task requiring phonological transformation. Statistical analysis of the data was performed using statistical parametric mapping (SPM96). Comparison of patterns of activation in dyslexic and normal reading children revealed significant differences in Brocas area and the left inferior temporal region for both, non-word reading and the phonological transformation task. The present data provide new evidence for alteration of the phonological system in dyslexic children, and in particular, the system that mediates assembled phonological coding.

Phonological processing in dyslexic children: a study combining functional imaging and event related potentials

Difficulties in phonological processing are currently considered one of the major causes for dyslexia. Nine dyslexic children and eight control children were investigated using functional magnetic resonance imaging (fMRI) during non-oral reading of German words. All subjects silently read words and pronounceable non-words in an event related potentials (ERP) investigation, as well. The fMRI showed a significant difference in the activation in the left inferior frontal gyrus between the dyslexic and control groups, resulting from a hyperactivation in the dyslexics. The ERP scalp distribution showed a significant distinction between the two groups concerning the topographic difference for left frontal electrodes in a time window 250-600 ms after stimulus onset for non-word reading. Both the fMRI and the ERP results support differences in phonological processing between dyslexic and normal-reading children.

Multicenter P300 Brain Mapping of Impaired Attention to Cues in Hyperkinetic Children

OBJECTIVE To measure specific neurophysiological attention deficits in children with hyperkinetic disorders (HD; the ICD-10 diagnosis for severe and pervasive attention-deficit/hyperactivity disorder [ADHD]). METHOD In a multicenter sample of 148 children with HD and control children aged 8 to 14 years, event-related potential maps were recorded during a cued continuous performance test (A-X/O-X). Maps to cues (requiring attention but no response) and distractors and performance were tested for differences between age- and sex-matched HD and control groups (n = 57 each), as well as between clinics (n = 5). RESULTS The N1, P3a, and P3b maps revealed reliable attention effects, with larger amplitudes after cues than after distractors, and only minor differences across clinics. Children with HD missed more targets, made more false alarms, and had larger N1 followed by smaller P3b amplitudes after cues than did controls. Cue-P3b amplitude correlated with detecting subsequent targets. Cue-P3b tomography indicated posterior sources that were attenuated in children with HD. CONCLUSIONS Brain mapping indicates that children with HD attend to cues (preceding potential targets) with increased initial orienting (N1) followed by insufficient resource allocation (P3b). These multiple, condition-specific attention deficits in HD within 300 msec extend previous results on ADHD and underline the importance of high temporal resolution in mapping severe attention deficits.

Practitioner Review: Preconditions and Outcome of Inpatient Treatment in Child and Adolescent Psychiatry

Inpatient care is expensive and should ideally be provided for children and adolescents with the most serious psychiatric disorders. However, only little is known about inpatient treatment, e.g. the factors influencing hospital admission, the content of care in the hospital, the appropriate norms for the duration of inpatient stays, the inpatient arrangements that result in the best outcomes, or connection with necessary aftercare services. There are many methodological problems with existing research. However, it can cautiously be concluded that psychiatric hospitalisation of children and adolescents is often beneficial, particularly if special aspects of treatment are fulfilled (e.g. good therapeutic alliance, treatment with a cognitive-based problem-solving skills training package, or planned discharge) and aftercare services are available. The continuum-of-care model is promising because it provides opportunities to achieve better integration between inpatient interventions and aftercare services.

Dyslexia: the possible benefit of multimodal integration of fMRI- and EEG-data.

Summary.Biological research about dyslexia has been conducted using various neuroimaging methods like functional Magnetic Resonance Imaging (fMRI) or Electroencephalography (EEG). Since language functions are characterized by both distributed network activities and speed of processing within milliseconds, high temporal as well as high spatial resolution of activation profiles are of interest: “where” can dyslexia specific activations be detected and “when” do language processes start to diverge between dyslexics and controls?Due to the network character of language processing, fMRI-constrained distributed source models based on EEG-data were computed for multimodal data integration. First single-case results show that this method could be a promising approach for the understanding of a repeatedly described experimental finding for dyslexia like that of an overactivation in inferior frontal language areas. Multimodal data analysis for the subjects presented here could probably demonstrate that inferior frontal overactivations are the consequence of a phonological deficit and could represent ongoing articulation processes used to solve phonologically challenging tasks.

The intellectual functioning of adolescents with anorexia nervosa and bulimia nervosa.

The aim of this study was to investigate the intellectual functioning of a large group of eating disordered adolescents in order to test two hypotheses, viz, that the intellectual functioning of eating disordered adolescents conforms to the normal distribution, and that eating disordered adolescents do not perform better in verbal abilities than in nonverbal abilities. Standard intelligence tests were applied to 190 consecutive out- and inpatients with eating disorder diagnoses. The results were compared with those of a group of patients with other disorders, similar in age, sex, SES, and year of admission. The IQ of the eating disordered patients was significantly higher than that of patients in the comparison group. Patients in the comparison group and bulimic patients, but not anorexic patients, showed better nonverbal than verbal intellectual performance.

Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients

The aim of the investigation was to detect neuropsychological markers, such as sustained and selective attention and executive functions, which contribute to the vulnerability to schizophrenia especially in young persons. Performance was assessed in 32 siblings and children of schizophrenic patients and 32 matched controls using Wisconsin Card Sorting Test, Colour-Word-Interference-Test, Trail Making Test, and d2-Concentration-Test. The first-degree relatives showed certain impairments on all four tests, in particular, slower times on all time-limited tests. These results suggest the need for more time when completing neuropsychological tasks involving selected and focused attention, as well as cognitive flexibility, as a possible indicator of genetic vulnerability to schizophrenia.

How to Avoid Spurious Cluster Validation? A Methodological Investigation on Simulated and fMRI Data

This paper presents an evaluation of a common approach that has been considered as a promising option for exploratory fMRI data analyses. The approach includes two stages: creating from the data a sequence of partitions with increasing number of subsets (clustering) and selecting the one partition in this sequence that exhibits the clearest indications of an existing structure (cluster validation). In order to achieve that the selected partition is actually the best characterization of the data structure, previous studies were directed to find the most appropriate validity function(s). In our analysis protocol, we first optimize the sequence of partitions according to the given objective function. Our study showed that an insufficient optimization of the partition, for one or more numbers of clusters, can easily yield a spurious validation result which, in turn, may lead the analyst to a misleading interpretation of the fMRI experiment. However, a sufficient optimization, for each included number of clusters, provided the basis for a reliable, adequate characterization of the data Furthermore, it enabled an adequate evaluation of the validity functions. These findings were obtained independently for three clustering algorithms (representing the hard and fuzzy clustering variant) and three up-to-date cluster validity functions. The findings were derived from analyses of Gaussian clusters, simulated data sets that mimic typical fMRI response signals, andreal fMRI data. Based on our results we propose a number of options of how to configure improved clustering tools.

Psychosocial Adversities Underestimated in Hyperkinetic Children

Abnormal psychosocial factors, assessed both clinically and by raters blind to clinical presentation, were examined in 21 hyperkinetic and 26 conduct disordered children. Blind raters found the frequency of psychosocial adversities to be similar in the two disorders. By contrast the clinical rater, who did know the diagnosis of patients, rated adverse psychosocial situations as much lower in hyperkinetic children than in children with conduct disorder. Logistic regression showed, particularly in the category of abnormal intrafamilial relationships (Lack of warmth in parent child relationship, Hostility or scapegoating of the child, Intrafamilial discord among adults), effects of the interaction between rater and knowledge of diagnosis. Clinical raters should be aware of abnormal psychosocial situations in hyperkinetic children and assess possible adverse effects on parents and children. Researchers should be aware of a possible bias in research interviews.

Course of adolescent psychotic disorder with schizoaffective episodes

This study examines educational/occupational outcome and social functioning of adolescents treated for psychosis (mean onset age 16.1 yrs±1.3). In a sample of 157 subjects, 26 patients with schizoaffective episodes (defined as any episode meeting ICD-9 criteria for schizoaffective psychosis, occurring at any time during the course of illness) were compared to 101 patients with schizophrenia, and to 30 affective disordered patients, all without schizoaffective episodes. Follow-up information (mean interval 7.3 yrs ±4.3) was obtained on 130 subjects. The three groups did not differ concerning sex, duration of first inpatient treatment, symptoms and social competence at discharge, nor at follow-up. At the time of outcome subjects with schizoaffective episodes showed greater similarities to schizophrenic than to severe affective disorder. Educational and occupational impairment was found in 72% of the schizoaffective group (schizophrenic group 79%, affective group 40%), obvious or more severe social disability in 86% of the schizoaffective group (schizophrenic 79%, affective 40%). Disabilities regarding performance of specific social roles and specific downward educational and occupational drifts were found to be more marked in schizoaffective than in affective disorder. Implications for further research and clinical practice are discussed.