The complex sulco-gyral pattern results from fetal and early childhood processes that shape the cortex anatomy from a smooth lissencephalic structure to a highly convoluted surface. Abnormal brain maturation has been suggested as risk factor for schizophrenia. Thus, measures of the cortical folding pattern could provide cues for the neurodevelopmental aspects of pathopsychology.

Brain morphometry softwares providing 3D sulci descriptors (e.g. surface) from MRI (Mangin, 2004 ; Cachia, 2007). This automatized method avoids biases inherent to image normalisation and partial volume effect. Therefore, statistics on sulcal measurements should generalize across patients. T1 MRI datasets were studied in at-risk subjects, adolescent onset schizophrenia, and patients with treatment-resistant depression and auditory hallucinations.

Decreased in sulci surface were detected in whole brain sulcal indices and in regional sulcal indices. Decreases in global sulcal indices were detected in most patient groups, except in at risk subjects. Decreases in local sulcal indices were detected in langage-related areas in resistant hallucinators (Cachia 2007), and confined to left temporal regions in adolescent schizophrenia (Pentilla, submitted). In patients with treatment-resistant depression, sulci descriptors differed in right hemisphere sulci adjacent to limbic regions (Pentilla, submitted).

The potential of the gyrification pattern for the inference of neuroimage-based developmental biomarkers will be further examined using multivariate classification approaches (Duchesnay 2006).

[1]. Mangin et al., Neuroimage 2004 - Cachia et al., Neuroimage 2007 – Duchesnay et al., Neuroimage 2006