A diffusion tensor imaging study of fasciculi in schizophrenia.
OBJECTIVE
Cognitive models propose that the symptoms and psychological impairments associated with schizophrenia arise as a consequence of impaired communication between brain regions, especially the prefrontal cortex and the temporal and parietal lobes. Functional imaging and electrophysiological data have provided evidence of functional dysconnectivity, but it is unclear whether this reflects an underlying problem with anatomical connectivity. This study used diffusion tensor imaging to examine the integrity of the major white matter fasciculi, which connects the frontal and temporal-parietal cortices, and the corpus callosum in patients with schizophrenia.


METHODS
A 1.5-T magnetic resonance scanner was used to acquire diffusion tensor images giving whole brain coverage at an isotropic 2.5-mm voxel size. Fractional anisotropy was measured in 33 patients with schizophrenia and 40 healthy comparison subjects with an automated voxel-based method of analysis.


RESULTS
There was reduced fractional anisotropy in patients with schizophrenia in regions corresponding to the superior longitudinal fasciculi bilaterally and in the genu of the corpus callosum. However, within the patient group, the propensity to experience auditory hallucinations was associated with relatively increased fractional anisotropy in superior longitudinal fasciculi and in the anterior cingulum.


CONCLUSIONS
Schizophrenia is associated with altered white matter integrity in the tracts connecting the frontal cortex with the temporal and parietal cortices and with the contralateral frontal and temporal lobes. The severity of these changes may vary with the pattern of symptoms associated with the disorder.
Shergill
Sukhwinder S
SS
Institute of Psychiatry, Kings College London, De Crespigny Park, UK. s.shergill@iop.kcl.ac.uk
Kanaan
Richard A
RA
Chitnis
Xavier A
XA
O'Daly
Owen
O
Jones
Derek K
DK
Frangou
Sophia
S
Williams
Steven C R
SC
Howard
Robert J
RJ
Barker
Gareth J
GJ
Murray
Robin M
RM
McGuire
Philip
P
D000328:Adult; D016880:Anisotropy; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000378:metabolism / Q000503:physiopathology*; D003337:Corpus Callosum / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006212:Hallucinations / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D009434:Neural Pathways / Q000378:metabolism / Q000473:pathology*; D010296:Parietal Lobe / Q000473:pathology; D017397:Prefrontal Cortex / Q000378:metabolism / Q000473:pathology*; D012559:Schizophrenia / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000378:metabolism / Q000473:pathology