Oades, R. D., Wild-Wall, N., Juran, S., Weisbrod, M., Chen; E. Y. H., Röpcke, B., (2004)
Mismatch negativity (MMN) sources in the frontal and temporal lobes of adolescent patients with schizophrenia: an ERP- and MR-imaging study.
Proceedings of the 16th World Congress of the International Association for Child and Adolescent Psychiatry and Allied Professions, 22-26 Aug 2004, Berlin, Germany (p.71 - 72).

Introduction: MMN is an electrophysiological measure of automatic auditory change detection. A smaller MMN in patients with schizophrenia may reflect altered frontal activity (Oades et al. 1995). We sought dipole sources in newly ill adolescent and older residual patients.

Methods: Following our report on
a) the coordinates for frontal and temporal lobe dipole-loci contributing to normal MMN (Jemel et al 2002)
we replicated this result using brain electrical source analysis (BESA) and MR-images of the brain
c) in healthy teenagers (mean age 17y) and adults (mean age 34y) and compared it with adolescent patients with a first episode of schizophrenia, and a group 15 years after the onset of schizophrenia in adolescence..

Results: For MMN associated with a frequency deviant tone asymmetric loci in the superior-temporal and left anterior-cingulate gyri were replicated, while that in the right inferior-frontal gyrus moved to the mid-frontal border (residual variance [RV] <1%).:
Healthy subjects showed maturational changes between the second and fourth decades that included a changed orientation of the left cingulate dipole and a more dorso-medial location of the right frontal dipole in older subjects:
Second: Patients showed a modest MMN reduction, a weaker left temporal lobe source but essentially similar loci (RV~1%). :
Third: Discrete changes in the locus of left temporal and cingulate sources were illustrated by plotting volumes around the group solution for individual’s data to 4% RV, with the radius illustrating the standard deviation of the distance to the solutions for other subjects’ loci;
Fourth: The left temporal lobe source was marginally more medial in patients (5 mm, p<0.01), while the left cingulate was more rostral (10 mm, p<0.0001).

The data show a degree of compensation of function despite altered source locations in the left hemisphere, even at onset in adolescence.
..... Support:
NW-W was supported by the Alfried Krupp von Bohlen u. Halbach Stiftung