Dysfunctional cortico-cerebellar circuits cause 'cognitive dysmetria' in schizophrenia.
We examined regional cerebral blood flow (rCBF) during a long-term recognition memory task for words in schizophrenic patients and in healthy subjects using positron emission tomography (PET). The task was designed so that performance scores were similar in the patient and control subjects. This memory retrieval task did not increase rCBF in the patients' prefrontal cortex, precuneus and cerebellum as much as it did in the control group. These results point to a dysfunctional corticocerebellar circuit leading to poorly coordinated mental activity ('cognitive dysmetria'), which could explain the broad range of schizophrenic symptoms. In addition, other brain areas were more activated by the task in the patient group than in the control group and may form a compensatory network performing the memory retrieval task by assisting or replacing the dysfunctional cortico-cerebellar circuit.
Wiser
A K
AK
Mental Health Clinical Research Center, University of Iowa, College of Medicine, Iowa City 52242-1057, USA.
Andreasen
N C
NC
O'Leary
D S
DS
Watkins
G L
GL
Boles Ponto
L L
LL
Hichwa
R D
RD
D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D002531:Cerebellum / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D011939:Mental Recall / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D012565:Schizophrenic Psychology; D014055:Tomography, Emission-Computed