Decrements in volume of anterior ventromedial temporal lobe and olfactory dysfunction in schizophrenia.
BACKGROUND
Patients with schizophrenia exhibit olfactory deficits, but it is unclear whether these represent a specific abnormality. The link between olfactory impairments and regional brain abnormalities has yet to be established.


OBJECTIVE
To determine whether patients with schizophrenia exhibit volumetric deficits in the anterior ventromedial temporal lobe, the target for neuronal inputs from the olfactory bulb, and whether these are related to olfactory performance deficits.


METHODS
A cohort study of patients and healthy control subjects who underwent both 1-mm spoiled-gradient echo magnetic resonance imaging and behavioral tests of olfaction and memory.


METHODS
Schizophrenia Research Center at the University of Pennsylvania, Philadelphia.


METHODS
Fifty-two patients with a DSM-IV diagnosis of schizophrenia and 38 healthy control subjects. Individuals were excluded for history of head trauma, significant substance abuse, and medical conditions affecting brain function or olfactory capacity.


METHODS
Gray matter volumes of the left and right temporal poles and the perirhinal and entorhinal cortexes; olfactory threshold detection sensitivity and identification test scores; composite indexes of verbal and spatial memory ability.


RESULTS
Patients had reduced volumes, relative to cranial size, in left (P =.003) and right (P =.01) perirhinal and left (P =.002) and right (P =.002) entorhinal cortexes, but not in the temporal pole. Perirhinal, but not entorhinal, cortical volume decrement was associated with decreased olfactory threshold sensitivity. Neither region was associated with impaired memory performance.


CONCLUSIONS
Patients with schizophrenia have reduced cortical volumes in brain regions that receive afferents directly from the olfactory bulb. Behavioral olfactory deficits are related to structural brain abnormalities in these regions.
Turetsky
Bruce I
BI
Schizophrenia Research Center, Department of Psychiatry, University of Pennsylvania, Philadelphia 19104, USA. turetsky@bbl.med.upenn.edu
Moberg
Paul J
PJ
Roalf
David R
DR
Arnold
Steven E
SE
Gur
Raquel E
RE
D000293:Adolescent; D000328:Adult; D001284:Atrophy; D004292:Dominance, Cerebral / Q000502:physiology; D018728:Entorhinal Cortex / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D000857:Olfaction Disorders / Q000175:diagnosis* / Q000503:physiopathology; D009830:Olfactory Bulb / Q000473:pathology / Q000503:physiopathology; D009833:Olfactory Pathways / Q000473:pathology / Q000503:physiopathology; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D012684:Sensory Thresholds / Q000502:physiology; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology