SPECT study of visual fixation in schizophrenia and comparison subjects.
BACKGROUND
The consistent association of impaired eye movements and schizophrenia suggests a relationship between the neurobiology of the illness and visual pursuit systems. Visual fixation (VF), an eye "movement" task at zero velocity, is the simplest such abnormality in schizophrenia patients and their relatives.


METHODS
We used a VF task for a functional imaging study. Six neuroleptic-free schizophrenia patients and eight gender and mean age matched comparison subjects had SPECT scans with 20 mCi of Tc99-HMPAO, during VF on a simple blue line intersection. MEDX data saved in ANALYZE format for SPM 95 was used to generate paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores.


RESULTS
Patients, compared to controls, had increased rCBF in both the parahippocampal gyrus (bilaterally) and in the right fusiform gyrus. They had decreased rCBF in the left frontal cortex, including medial and superior frontal gyri and anterior cingulate. Overall, compared to controls, patients had medial temporal lobe hyperperfusion along with left prefrontal hypoperfusion.


CONCLUSIONS
These findings are consistent with the hypothesized imbalance between the medial temporal and frontal lobes that is postulated for schizophrenia. It was of interest that the relative rCBF differences between schizophrenia patients and controls in this small sample were observable with this cognitively non-demanding visual fixation task.
Malaspina
D
D
Department of Clinical Psychobiology, New York State Psychiatric Institute, New York 10032, USA.
Storer
S
S
Furman
V
V
Esser
P
P
Printz
D
D
Berman
A
A
Lignelli
A
A
Gorman
J
J
Van Heertum
R
R
D000328:Adult; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales; D012438:Saccades / Q000502:physiology; D012559:Schizophrenia / Q000175:diagnosis / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon; D014794:Visual Fields / Q000502:physiology