Antineuronal antibodies in a group of children with obsessive-compulsive disorder and Tourette syndrome.

An autoimmune hypothesis has been suggested for early onset obsessive-compulsive disorder and Tourette syndrome. The term: Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) has been proposed as an aetiological subtype of OCD and TS, related to a Group A beta haemolytic streptococcal (GABHS) infection that triggers an autoimmune response. Antineural antibodies have been studied and found in the sera of some patients with these disorders, and they are thought to cross-react with streptococcal and basal ganglia antigens. The present study included 32 prepubertal-onset OCD patients, 21 with TS diagnosis (some of them meeting criteria for PANDAS) and 19 normal children, all aged between 9 and 17 years. Antibodies were assayed by immunohistochemistry and immunoblot. Special attention was paid to the methodology and a high serum dilution was used to minimize non-specific binding. No anti-basal ganglia antibodies were detected by immunohistochemistry in any of the samples. Two proteins, with approximate molecular weights of 86 kDa and 55 kDa, were found in sera from 7 patients. Though the study supports the hypothesis of an autoimmune process underlying OCD or TS in some patients, further research is needed.

Volume changes in gray matter in first-episode neuroleptic-naive schizophrenic patients treated with risperidone.

Structural neuroimaging techniques have consistently shown that treatment of schizophrenic patients with conventional antipsychotics causes an increase in basal ganglia volume. However, findings in schizophrenic patients treated with the newer atypical antipsychotic drugs are less consistently reported. To explore this issue, the authors used a whole-brain, unbiased, and automated technique for comparing brain structural features across scans in schizophrenic patients before and after a treatment with the atypical antipsychotic risperidone. T1-weighted images from 11 first-episode neuroleptic-naive schizophrenic patients were processed and analyzed for regions of interest (basal ganglia) by using optimized voxel-based morphometry. Scans were repeated after 3 months of continuous treatment with risperidone. Region of interest-based voxel-based morphometry analyses revealed increases in gray matter volume for the right and left caudate nuclei and for the left accumbens after the treatment with risperidone. Hence, in our sample of schizophrenic patients, treatment with risperidone was associated, in contrast to the findings for other atypical antipsychotics, with an increase in basal ganglia volume. Such discrepancy could be related to the pharmacodynamics of risperidone (the atypical antipsychotic showing the higher affinity for D2 receptors) and the rather high mean doses used in our study (ie, 6.05 mg/d).

Amygdalar atrophy in panic disorder patients detected by volumetric magnetic resonance imaging.

It has been suggested that the pathophysiology of panic disorder (PD) may involve abnormalities in several brain structures, including the amygdala. To date, however, no study has used quantitative structural neuroimaging techniques to examine amygdalar anatomy in this disorder. Volumetric magnetic resonance imaging (MRI) studies of the amygdalas, hippocampi, and temporal lobes were conducted in 12 drug-free, symptomatic PD patients (six females and six males), and 12 case-matched healthy comparison subjects. Volumetric MRI data were normalized for brain size. PD patients were found to have smaller left-sided and right-sided amygdalar volumes than controls. No differences were found in either hippocampi or temporal lobes. These findings provide new evidence of changes in amygdalar structure in PD and warrant further anatomical and MRI brain studies of patients with this disorder.

Parahippocampal gray matter density in panic disorder: a voxel-based morphometric study.

OBJECTIVE: The authors examined possible cerebral gray matter abnormalities in patients with panic disorder. METHOD: Gray matter concentration in 18 panic disorder outpatients and 18 healthy subjects was compared by using a voxel-based morphometry approach. RESULTS: Gray matter density of the left parahippocampal gyrus was significantly lower in patients with panic disorder compared with healthy subjects. CONCLUSIONS: This result provides further support for the involvement of the parahippocampal area in the pathophysiology of panic disorder.

Reduced levels of creatine in the right medial temporal lobe region of panic disorder patients detected with (1)H magnetic resonance spectroscopy.

In vivo proton magnetic resonance spectroscopy ((1)H MRS) was used to study possible neurochemical abnormalities in drug-free, symptomatic panic disorder patients at rest. (1)H MRS was performed in 11 panic disorder patients and 11 healthy age- and sex-matched comparison subjects. Levels of brain metabolites were determined in the right medial temporal lobe region (encompassing the whole amygdala and part of the hippocampus) and in the medial prefrontal cortex on the basis of previous work with both structural and functional neuroimaging techniques. The concentration of creatine and phosphocreatine, metabolites involved in energy-dependent systems in brain, was significantly lower in the right medial temporal lobe region of panic disorder patients compared to healthy subjects. No significant differences between the two groups were observed in the medial prefrontal cortex. These results provide neurochemical evidence suggesting the involvement of the amygdalohippocampal region in the pathogenesis of panic disorder.

Un 'mundo feliz' / A happy world

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Alteraciones inmunológicas asociadas a tics, TOC y PANDAS / Immunological features associated with tics, TOC and PANDAS

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