Resting neural activity distinguishes subgroups of schizophrenia patients.
BACKGROUND
Schizophrenia is etiologically heterogeneous. It is anticipated, but unproven, that subgroups will differ in neuropathology and that neuroimaging may reveal these differences. The optimal imaging condition may be at rest, where greater variability is observed than during cognitive tasks, which more consistently reveal hypofrontality. We previously demonstrated symptom and physiologic differences between familial and sporadic schizophrenia patients and hypothesized that the groups would show different resting regional cerebral blood flow (rCBF) patterns.


METHODS
Ten familial and sixteen sporadic schizophrenia patients and nine comparison subjects had single photon emission computed tomography imaging during passive visual fixation. Images were spatially normalized into Talairach coordinates and analyzed for group rCBF differences using SPM with a Z value threshold of 2.80, p < .001.


RESULTS
The subgroups had similar age, gender, illness duration, and medication treatment. Sporadic patients had hypofrontality (anterior cingulate, paracingulate cortices, left dorsolateral and inferior-orbitofrontal), whereas familial patients had left temporoparietal hypoperfusion; all of these regions show resting activity in healthy subjects. Both groups hyperperfused the cerebellum/pons and parahippocampal gyrus; additional hyperperfusion for sporadic patients was observed in the fusiform; familial patients also hyperperfused the hippocampus, dentate, uncus, amygdala, thalamus, and putamen.


CONCLUSIONS
Familial and sporadic schizophrenia patients had different resting rCBF profiles, supporting the hypothesis that certain subgroups have distinct neural underpinnings. Different neuropathologic processes among subgroups of schizophrenia patients may account for the prior contradictory results of resting imaging studies.
Malaspina
Dolores
D
New York State Psychiatric Institute, Columbia University, 1051 Riverside Drive, New York, NY 10032, USA. dm9@columbia.edu
Harkavy-Friedman
Jill
J
Corcoran
Cheryl
C
Mujica-Parodi
Lilianne
L
Printz
David
D
Gorman
Jack M
JM
Van Heertum
Ronald
R
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology; D005192:Family Health; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012039:Regional Blood Flow / Q000502:physiology; D012146:Rest / Q000502:physiology*; D012559:Schizophrenia / Q000145:classification* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods