P0130 - Grey matter correlates of skin conductance levels in patients with schizophrenia and healthy volunteers: A voxel-based morphometry (vbm) study

Abstract

Electrodermal activity has been considered as a potential source to identify subgroups of schizophrenics. However, the neural mechanisms that are the base of the electrodermal responsiveness in schizophrenia are not well-known. The present study aimed to determine if schizophrenic patients with different skin conductance levels (SCL) show differences in grey matter (GM) volume estimated through VBM. Thirty-four schizophrenic patients paired with healthy volunteers, matched according to sex, age, handedness, socio-economic status and years of education, were selected. All patients were using anti-psychotics, and were included only when their score in the BPRS was lower then “present in mild degree” in all the scale items, except for negative symptoms. The electrodermal activity was measured during five minutes at rest and in comfortable conditions. Three groups were obtained, according to the electrodermal level: control, schizophrenic with normal SCL and schizophrenic with low SCL. MRI was performed with a Siemens Magneton 1.5T imaging system. The optimized VBM protocol was implemented within MATLAB 7.0 (Mathworks Inc.) through Statistical Parametric Mapping 2. Compared to controls, schizophrenic patients presented abnormalities in regional GM volume in superior and medial frontal lobes, paracentral lobule, cingulate, transverse temporal, insula, precuneus and occipital lobe. Regarding the schizophrenia groups, it was observed that the low SCL group presented smaller regional GM density in the right superior frontal lobe and in the right anterior cingulated. Accordingly, these results suggest that these brain areas may be involved in the modulation of SCL in schizophrenia and could be altered in a subgroup of patients.