A 4.0-T fMRI study of brain connectivity during word fluency in first-episode schizophrenia.
OBJECTIVE
To use functional magnetic resonance imaging (fMRI) to investigate functional connectivity, and hence, underlying neural networks, in never-treated, first-episode patients with schizophrenia using a word fluency paradigm known to activate prefrontal, anterior cingulate, and thalamic regions. Abnormal connectivity between the prefrontal cortex (PFC) and other brain regions has been demonstrated in chronic, medicated patients in previous positron emission tomography (PET) studies, but has not to our knowledge, previously been demonstrated using both first-episode, drug-naïve patients and fMRI technology.


METHODS
A 4.0-Tesla (T) fMRI was used to examine activation and functional connectivity [psychophysiological interactions (PPIs)] during a word fluency task compared to silent reading in 10 never-treated, first-episode patients with schizophrenia and 10 healthy volunteers of comparable age, sex, handedness, and parental education.


RESULTS
Compared to healthy volunteers, the schizophrenia patient group exhibited less activation during the word fluency task, mostly in the right anterior cingulate and prefrontal regions. Psychophysiological interactions between right anterior cingulate and other parts of the brain revealed a localized interaction with the left temporal lobe in healthy volunteers during the task and a widespread unfocussed interaction in patients.


CONCLUSIONS
These findings suggest anterior cingulate involvement in the neuronal circuitry underlying schizophrenia.
Boksman
Kristine
K
University of Western Ontario, 1151 Richmond Street, London, Ontario, Canada N6A 5B8.
Théberge
Jean
J
Williamson
Peter
P
Drost
Dick J
DJ
Malla
Ashok
A
Densmore
Maria
M
Takhar
Jatinder
J
Pavlosky
William
W
Menon
Ravi S
RS
Neufeld
Richard W J
RW
D000328:Adult; D001921:Brain / Q000503:physiopathology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D013788:Thalamus / Q000503:physiopathology; D014705:Verbal Behavior; D014825:Vocabulary