Cortical signature of neurological soft signs in recent onset schizophrenia.

Motor symptoms such as neurological soft signs (NSS) are characteristic phenomena of schizophrenia at any stage of the illness. Neuroimaging studies in schizophrenia patients have shown regional thinning of the cortical mantle, but it is unknown at present whether NSS are related to cortical thickness changes. Whole brain high-resolution magnetic resonance imaging at 3 Tesla was used to investigate cortical thickness in 28 patients with recent-onset schizophrenia. Cortical reconstruction was performed with the Freesurfer image analysis suite. NSS were examined on the Heidelberg Scale and related to cortical thickness. Age, education, and medication were considered as potential confounders. Higher NSS scores were associated with morphological changes of cortical thickness in multiple areas comprising paracentral gyrus, postcentral lobule, precuneus, inferior parietal lobule and temporal lobe. Our results confirm the hypothesis of a significant relationship between cortical thickness changes and the extent of NSS in schizophrenia. Investigation of cortical thickness may help to explain subtle motor symptoms such as NSS in schizophrenia.