Diffusion tensor imaging of the superior longitudinal fasciculus and working memory in recent-onset schizophrenia.
BACKGROUND
Structural and functional abnormalities in frontal-parietal circuitry are thought to be associated with working memory (WM) deficits in patients with schizophrenia. This study examines whether recent-onset schizophrenia is associated with anatomical changes in the superior longitudinal fasciculus (SLF), the main frontal-parietal white matter connection, and whether the integrity of the SLF is related to WM performance.


METHODS
We applied a novel registration approach (Tract-Based Spatial Statistics [TBSS]) to diffusion tensor imaging data to examine fractional anisotropy (FA) in the left and right SLF in 12 young adult patients with recent-onset schizophrenia and 17 matched control subjects.


RESULTS
Schizophrenia patients showed lower FA values than control subjects across the entire SLF, with particular deficits on the left SLF. Fractional anisotropy values were correlated with performance on a verbal WM task in both patient and control groups in the left but not right SLF.


CONCLUSIONS
Recent-onset schizophrenia patients show deficits in frontal-parietal connections, key components of WM circuitry. Moreover, the integrity of this physiological connection predicted performance on a verbal WM task, indicating that this structural change may have important functional implications. These findings support the view that schizophrenia is a disorder of brain connectivity and implicate white matter changes detectable in the early phases of the illness as one source of this dysfunction.
Karlsgodt
Katherine H
KH
Department of Psychology, University of California, Los Angeles, California 90095-1563, USA. karlsgodt@psych.ucla.edu
van Erp
Theo G M
TG
Poldrack
Russell A
RA
Bearden
Carrie E
CE
Nuechterlein
Keith H
KH
Cannon
Tyrone D
TD
D000203:Activities of Daily Living / Q000523:psychology*; D000293:Adolescent; D000328:Adult; D001284:Atrophy; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D038524:Diffusion Magnetic Resonance Imaging; D004193:Discrimination Learning / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology / Q000502:physiology; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology*; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010700:Phonetics; D011618:Psychotic Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D014706:Verbal Learning / Q000502:physiology