Background. Many studies have separately reported abnormalities
of frontal and temporal lobe
structures in schizophrenia, but little is known of structural
fronto-temporal associations in this
condition. We investigated whether male patients with chronic schizophrenia
would show abnormal patterns of correlation between regional brain volumes.
Methods. Structural magnetic resonance images of the brain
in
42 patients were compared with
43 matched unaffected controls. We explored the pattern of association
between regional brain
volumes by correlational analyses, and non-parametrically tested for
significance of between-group differences by randomization.
Results. The schizophrenics demonstrated significant volume
deficits in
several brain regions (left
temporal lobe and hippocampus, right dorsolateral prefrontal cortex), and
significant volume
increases in the ventricular system (third ventricle and left temporal
horn
of the lateral ventricle). Controls demonstrated large positive correlations
(r>0·4) between prefrontal and
temporal lobe regions. By contrast, inter-regional correlations significantly
reduced in schizophrenics included those between prefrontal, anterior
cingulate and temporal regions, and between
posterior cingulate and hippocampus (P<0·05). The
most salient abnormality in patients was a
dissociation between prefrontal and superior temporal gyrus volumes
(P<0·01).
Conclusions. These results support the existence of a relative
‘fronto-temporal dissociation’ in schizophrenia
which we suggest may be due to lack of mutually trophic influences during
frontal and
temporal lobe development.