Neural correlates of formal thought disorder in schizophrenia: preliminary findings from a functional magnetic resonance imaging study.
BACKGROUND
Formal thought disorder (FTD) is a core symptom of schizophrenia, but its pathophysiology is little understood. We examined the neural correlates of FTD using functional magnetic resonance imaging.


METHODS
Blood oxygenation level-dependent contrast was measured using functional magnetic resonance imaging while 6 patients with schizophrenia and 6 control subjects spoke about 7 Rorschach inkblots for 3 minutes each. In patients, varying degrees of thought-disordered speech were elicited during each "run." In a within-subject design, the severity of positive FTD was correlated with the level of blood oxygenation level-dependent contrast in the 2 runs that showed the highest variance of FTD in each patient.


RESULTS
The severity of positive FTD in patients was negatively correlated (P<.001) with signal changes in the left superior and middle temporal gyri. Positive correlations were evident in the cerebellar vermis, the right caudate body, and the precentral gyrus.


CONCLUSIONS
The severity of positive FTD was inversely correlated with the level of activity in the Wernicke area, a region implicated in the production of coherent speech. Reduced activity in this area might contribute to the articulation of incoherent speech. Because of the small sample size, these findings should be considered preliminary.
Kircher
T T
TT
Department of Psychiatry, University of Tuebingen, Osianderstr. 24, D-72076 Tuebingen, Germany. tilo.kircher@uni-tuebingen.de
Liddle
P F
PF
Brammer
M J
MJ
Williams
S C
SC
Murray
R M
RM
McGuire
P K
PK
D000328:Adult; D001921:Brain / Q000098:blood supply / Q000502:physiology* / Q000503:physiopathology; D002421:Caudate Nucleus / Q000098:blood supply / Q000502:physiology; D002531:Cerebellum / Q000098:blood supply / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D010100:Oxygen / Q000097:blood; D012039:Regional Blood Flow; D012392:Rorschach Test; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D013060:Speech / Q000502:physiology*; D013702:Temporal Lobe / Q000098:blood supply / Q000502:physiology
D010100:Oxygen