Biomedical subjects

Wagner F Gattaz

Publications and source records attributed to Wagner F Gattaz.

26 records · Page 2Linked to original sources

PubMed2003

[Münchhausen syndrome: diagnosis and management].

The authors review the literature on Münchhausen syndrome, and ilustrate the clinical features of the disorder with the description of a characteristic case. Diagnosis and differential diagnosis are discussed with regard to other somatoform disorders such as conversion disorder and somatization disorder as well as to malingering and schizophrenia. The awareness of general practitioners and surgeons regarding this syndrome may avoid the exposure of these patients to serious complications of unnecessary medical and surgical procedures. The management of Müchhausen syndrome is aggravated by the low compliance in these patients. Early diagnosis could to a considerable extent prevent the iatrogenic risks. The authors recommend that patients presenting the psychopathological features of a Münchhausen syndrome should be conservatively observed and an attempt to clarify both the medical and the psychiatric diagnosis should be made before any invasive procedure is undertaken.

Adult↗

PubMed2003

Increased phospholipase A2 activity in schizophrenia with absent response to niacin.

An absent response to the niacin skin test has been reported to occur in about 80% of schizophrenic patients, as compared to 20% of healthy individuals. Niacin provokes redness in skin caused by a capillary vasodilatation mediated by prostaglandins. The metabolism of prostaglandins is regulated by the enzyme phospholipase A2 (PLA2). Several studies have reported increased PLA2 activity in schizophrenia. In this study we investigated the relationship between niacin response and PLA2 activity in 38 drug-free schizophrenic patients and in 28 healthy controls. Twenty-two of these patients were reevaluated after 8 weeks under treatment with new generation antipsychotic drugs. Niacin response was absent in 23% of the schizophrenic patients and in 14% in controls (n.s.). PLA2 activity was higher in schizophrenics than in controls (344+/-115 vs. 290+/-71 pmol/ml/min; p=0.03). Patients with absent response to niacin had the highest PLA2 activity as compared to those with positive response (426+/-155 vs. 319+/-111; p=0.02). After 8 weeks on antipsychotic treatment, PLA2 activity was reduced (355+/-115 before, 267+/-39 after, p=0.001) and 4 out of 13 patients with absent response to niacin converted to positive. The reduction of PLA2 activity in these patients was higher than in patients who remained with absent response (36% vs. 23%). Our data support the findings that absent response to niacin is more frequent in schizophrenic than in healthy individuals although the magnitude of the difference was smaller than that reported in the literature. The relationship between absent response to niacin in schizophrenia and increased PLA2 activity suggests further that the skin test may be useful to easily identify a subgroup of patients with a disordered phospholipid metabolism.

Adult↗

PubMed2003

Rightward cerebral asymmetry in subtypes of schizophrenia according to Leonhard's classification and to DSM-IV: a structural MRI study.

Although well documented, brain structural abnormalities in schizophrenia are non-specific, and morphometric parameters show significant overlap between patients and healthy controls. Such inconsistencies in neuroimaging findings could represent different levels of severity along a single pathogenic process or distinct clinical and etiopathological psychoses within a schizophrenic spectrum. The aim of the present study was the investigation of distinct brain abnormalities in different subtypes of schizophrenia. Forty patients were classified according to DSM-IV and Leonhard's classifications. Psychopathology was assessed by the Positive and Negative Syndrome Scale (PANSS) and the Negative Symptom Rating Scale (NSRS). Patients were compared to 20 healthy volunteers on volumetric measures of cerebral structures (hemisphere, hippocampus and planum temporale) and ventricular-brain ratio (VBR) obtained by magnetic resonance imaging. Patients showed rightward asymmetry of cerebral hemispheres and increased VBR. Rightward asymmetry correlated with severity of negative symptoms and prevailed in the systematic forms of Leonhard, suggesting a distinct pattern of left hemisphere abnormality in this subgroup of psychoses. Increased VBR values showed a single normal distribution in the subgroups, indicating that ventricular enlargement is not restricted to a subgroup but is present to a certain degree in all cases.

Adult↗

PubMed2003

Association of a new polymorphism in ALOX12 gene with bipolar disorder.

Bipolar disorder (BPD) is characterised by episodes of excitement interspersed with periods of depression. The role of genetic factors in BPD is indicated by studies in monozygotic twins showing 40-70 % of concordance. Studies using genetic markers showed linkage of genes for affective disorders in different chromosome regions, emphasising the polygenic and multifactorial traits. The main goal of our research is to search non-synonymous SNPs (those that result in modifications in protein sequence) in genes that can be associated with psychiatric diseases as suggested by genomic mapping and/or by physiological function of the protein. Using DNA sequencing we could confirm a new non-synonymous SNP in the conservative domain of the ALOX12 gene (17p13.1), suggested by EST alignment. This SNP is an alteration from G to A that leads to a change of an arginine (A) to a glutamine in one of the most important domains of the protein. This SNP was evaluated by DNA sequencing in 182 patients with BPD and 160 control individuals. An increased presence of allele A among patients (60 % in controls and 73.1 % in cases; chi(2) = 6.581, P = 0.010; OR = 1.8095, 95 % CI = 1.1477-2.853) was found, suggesting an association of this polymorphism with the BPD in this Brazilian sample.

Adolescent↗

PubMed2003

The generators of slow potentials obtained during verbal, pictorial and spatial tasks.

The purpose of this study was to test whether slow cortical electrical activity is specific to performance on verbal, pictorial and spatial tasks. Twenty-nine healthy subjects were required to compare pairs of visual stimuli separated by a delay of 2.5 s in a S1-S2 contingent negative variation-type paradigm. Slow potentials (SPs) were recorded by high-resolution EEG (123 channels) and their generators modeled by current density reconstruction using individual MRIs as source space models. Activity in each architectonic area of Brodmann was scored with respect to individual maximum current by a percentile method. Results showed a multifocal pattern of current density foci comprising the SP generators, including frontal and posterior cortices in all subjects, with the most active areas being common to the three tasks. In spite of the intersubject variability in the sets of active areas for each given task, a few cortical areas were observed to discriminate between tasks in a statistically significant way: the verbal task corresponded to stronger electrical activity in right area 45 than the other tasks; the spatial to weaker activity in right area 38 and left area 5 than the other tasks; the pictorial, compared to the spatial task, to stronger activity in left area 39; the verbal, compared to the spatial task, to stronger activity in left area 10, and compared to the pictorial, to weaker activity in right area 20. The present method of SP analysis may aid in the functional mapping of human association cortices in individual cases. We discuss our results emphasizing intersubject variability in cortical activity patterns and the possibility of finding more universal patterns.

Adult↗

PubMed2003

[Tardive dyskinesia: pergolid, a possible therapeutic option].

OBJECTIVE: There's still no effective treatment established for Tardive Dyskinesia. Aim of the study was to analyse the effect of pergolide, a D1 and D2 receptor agonist with prevalence for presynaptic auto receptors, in oro-facial tardive dyskinesia by means of a double-blind, placebo controlled cross-over study. Low-dose pergolide should activate presynaptic auto receptors, decrease dopamintransmission and reduce tardive dyskinesia. METHOD: Assessment of dyskinesia was performed with the computer-assisted technique Digital-Imaging-Processing in addition to the clinical scale AIMS (Abnormal-Involuntary-Movement-Scale). 10 patients with oro-facial dyskinesia were examined for alteration to dyskinesia, psychopathology, vital functions and laborchemical parameter. RESULTS: Dyskinesia decreased 25 % for relax and 17 % for task conditions under pergolide treatment. Low-dose pergolide showed no side effects or worsening of the psychopathological state. Results of the Digital-Imaging-Processing correlated significantly with the results of clinical AIMS scale, but the computer-assisted technique gives more detailed information about degree and type of the movement disorder. CONCLUSION: Results suggest a therapeutic effect of pergolide in tardive dyskinesia, this has to be verified with a larger study population and longer observation. Assessment of dyskinesia is rater independent and more significant with the computer-assisted technique.

Adult↗

PubMed2003

Reduced cortical folding in schizophrenia: an MRI morphometric study.

OBJECTIVE: Although well documented, regional brain structural abnormalities in schizophrenia are nonspecific, and morphometric parameters show significant overlapping between patients and healthy comparison subjects. An increasing number of studies have focused on supraregional models involving abnormalities of the neuronal circuitry between cortical regions in schizophrenia. The aim of the present study was to investigate cortical folding as an index of the neuronal wiring in different subtypes of schizophrenia. METHOD: Magnetic resonance imaging measures of gyrification index in intervals of 3.6 mm along the total cerebral cortex were compared in 40 patients with DSM-IV schizophrenia and 20 healthy subjects. Psychopathology was assessed with the Positive and Negative Syndrome Scale, Brief Psychiatric Rating Scale, and the Negative Symptom Rating Scale. RESULTS: The schizophrenia patients showed significantly reduced bilateral cortical folding relative to healthy comparison subjects. Such reductions were more pronounced in those with the disorganized subtype and showed an inverse correlation with negative symptoms and a positive correlation with positive symptoms. The paranoid subtype showed reduced cortical folding that was restricted to the left hemisphere. CONCLUSIONS: These results from a larger patient group confirm a previous report of reduced cortical folding in schizophrenia patients. They also suggest a distinct pattern of abnormality between schizophrenia subtypes regarding the process of cerebral lateralization and are in agreement with the neurodevelopmental hypothesis of schizophrenia.

Adult↗

PubMed2002

Multifocal slow potential generation revealed by high-resolution EEG and current density reconstruction.

In this work we used high-resolution EEG (123 channels) and current density reconstruction (CDR) to analyze the generators of slow potentials (SPs) in 31 healthy individuals. SPs were obtained during a task-performance feedback anticipation paradigm. The task consisted of a visual paired-associate memory test, with correct performance on single trials indicated by pleasant visual stimuli and incorrect performance by an unpleasant sound. We used realistic models of each subject's head based on their magnetic resonance images (MRIs) to estimate the potentials in the intracranial compartments and to define the source space using individual cortical geometry. Source reconstruction was performed by an Lp-norm minimization algorithm. Results showed a multifocal pattern of current density foci in various association cortices, including prefrontal areas 9 and 10 of Brodmann in all subjects. Posterior cortical areas also contributed importantly to the SP, for instance extrastriate area 19 and parietal area 7, in 90% of the subjects. According to our modeling, we conclude that even the pure stimulus-anticipation SP obtained here, as opposed to traditional motor-task contigent negative variation (CNVs), is not exclusively prefrontal in origin, being generated by multiple association areas. We discuss our results with respect to new possibilities in large-scale cortical physiology and with respect to their application in psychiatry.

Adult↗