Medial temporal hypoperfusion and aggression in Alzheimer disease.
BACKGROUND
It is not understood why some patients with Alzheimer disease (AD) display aggression and others do not.


OBJECTIVE
To examine the relation between regional brain perfusion and aggression in AD.


METHODS
Single-photon emission computed tomographic scans were coregistered to a standardized template in Talairach space, generating mean ratios of uptake referenced to the cerebellum.


METHODS
Forty-nine outpatients (25 men and 24 women; mean +/- SD age, 74 +/- 11 years) with probable AD (Mini-Mental State Examination score, 17.7 +/- 5.0; 30 aggressive and 19 nonaggressive), comparable in age, sex, and severity of cognitive impairment.


METHODS
Regional perfusion ratios were determined for 5 bilateral regions of interest: orbitofrontal, middle medial temporal, inferior medial temporal, hypothalamus/thalamus, and anterior cingulate.


RESULTS
Compared with nonaggressive patients, aggressive ones displayed hypoperfusion in the right and left middle medial temporal regions of interest (P = .02 for both), but not the others (all (t tests, unpaired, 2-tailed). On regression analyses, right middle temporal hypoperfusion (P = .001), younger age (P = .002), greater activity disturbances (P = .004), and higher Mini-Mental State Examination scores (P = .04) independently predicted aggression, accounting for 44% of the total variance (F = 8.7; P<.001). Statistical parametric mapping analyses supported right middle medial temporal hypoperfusion in the aggressive group (P = .008).


CONCLUSIONS
In this sample of patients with AD, the right middle medial temporal region emerged as an important neural correlate of aggression.
Lanctôt
Krista L
KL
Neuropharmacology Research, Department of Psychiatry, Cognitive Neurology Unit, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Ontario, Canada. Krista.Lanctot@sw.ca
Herrmann
Nathan
N
Nadkarni
Neelesh K
NK
Leibovitch
Farrell S
FS
Caldwell
Curtis B
CB
Black
Sandra E
SE
D000368:Aged; D000369:Aged, 80 and over; D000374:Aggression; D000544:Alzheimer Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D013702:Temporal Lobe / Q000000981:diagnostic imaging* / Q000473:pathology*; D015899:Tomography, Emission-Computed, Single-Photon