Abnormal cortical folding in high-risk individuals: a predictor of the development of schizophrenia?
BACKGROUND
A number of studies have found localized differences in the appearance and extent of cortical folding between the brains of schizophrenic patients and healthy control subjects. This study aimed to determine whether, within individuals at genetic high risk for schizophrenia, there are pre-existing differences in gyral folding between those who subsequently develop the disease and those who remain unaffected.


METHODS
Assessment was conducted on baseline magnetic resonance imaging scans of 30 young adults grouped into 14 who remained unaffected and 16 who subsequently developed schizophrenia. The gyrification index (GI), the ratio of the inner and outer cortical surface contours, was measured bilaterally on every second 1.88-mm image slice in four specifically defined lobar regions. Independent t tests and volume and genetic liability correlations were conducted for each region, followed by a post hoc examination.


RESULTS
Right prefrontal lobe GI values were significantly increased in individuals who subsequently developed schizophrenia. Post hoc examination suggested that the areas of greatest increase lay anteriorly and laterally in Brodmann areas 9 and 10. Correlations with volume and analysis of covariance suggested some overlap between GI and volume measures.


CONCLUSIONS
Differences in frontal lobe GI might reflect disturbed or abnormal connectivity predictive of subsequent schizophrenia.
University Department of Psychiatry, Royal Edinburgh Hospital, Edinburgh, UK.
Jonathan M
JM
Harris
Heather
H
Whalley
Shona
S
Yates
Patrick
P
Miller
Eve C
EC
Johnstone
Stephen M
SM
Lawrie
D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000473:pathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011237:Predictive Value of Tests; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology / Q000473:pathology*