Combined evaluation of structural and electrophysiological features in brain

Subject: The aim of this study was to establish an association between the structural features of the brain or its infrastructures, and their underlying functions. The secondary aim was to show how volumetric changes are related to electrophysiological changes in the brain and its infrastructures among schizophrenia (SCH) patients.Methods: The study was comprised of 25 healthy participants and a group of 28 patients diagnosed with schizophrenia according to DSM-IV criteria. We compared Heschl? s gyrus (HG) and prefrontal cortex (PFC) volume in schizophrenia patients and healthy controls, from T1-weighted MR images of the whole brain, using a new manual tracing technique. The HG comprises the primary auditory cortex, and is implicated in auditory and speech processing. The HG measurements were validated with both inter- and intra-rater comparisons. The structural data were correlated with electroencephalographic performance on an auditory evoked potential. The amplitude, latency and global field power (GFP) of N1P2 and P400 components comprised the Electrophysiological (EEG) data which was integrated with MRI images using the Curry program to obtain EEG signal projection.Results: The results showed significant reduction of PFC white matter and HG grey matter volumes in the patients compared to healthy controls. Left HG was larger than right HG in both patient and control group, Patients also displayed reduction in voltage of N1P2 and P400 amplitude. The correlation between volumetric and electrophysiological data was able to differentiate patient population from healthy subjects.Conclusions: Structural and functional changes are found in schizophrenia patients in course of illness. Reduction in GPR values show decreased electrophysiological activity accompanying volume loss. The integration of MRI images with electrophysiological data clearly shows this interaction.