Hypofrontality and negative symptoms in patients with dementia of Alzheimer type.
OBJECTIVE
The purpose of the current study was to examine the relation between regional cerebral blood flow (rCBF) and negative symptoms (NS) in patients with dementia of Alzheimer type (DAT).


BACKGROUND
Negative symptoms in neuropsychiatric disorders were associated with altered rCBF in frontal cortex.


METHODS
Twenty-five subjects with a diagnosis of DAT were administered the Scale for the Assessment of Negative Symptoms (SANS), the Positive and Negative Symptom Scale, the Hamilton Rating Scale for Depression, and the Mini-Mental State Examination. The subjects were divided into two groups by means of a median split with regard to NS severity (high NS group, N = 12; low NS group, N = 13). Each patient underwent a single photon emission tomography scan using 99mTc-HMPAO at rest. Cortical and subcortical regions of interest were symmetrically defined in each hemisphere. Cortical-to-cerebellar perfusion ratios were established quantitatively using ADAC software.


RESULTS
High NS group subjects had a significantly lower rCBF than low NS group subjects in the frontal cortex and cingulate gyrus (MANOVA: p = 0.022) as a result of differences in the dorsolateral prefrontal cortex bilaterally (right: F = 12.12, p = 0.002; left: F = 6.55, p = 0.02) and in the frontal cortex, mainly in the right hemisphere (right: F = 6.33, p = 0.02; left: F = 3.26, p = 0.08). For all the subjects (N = 25), there were negative correlations between the SANS total score and rCBF, most prominently in the dorsolateral prefrontal cortex bilaterally (right: r = -0.48, p <0.01; left: r = -0.49, p = 0.01). No significant correlation was found between rCBF in any of the regions of interest and either the Mini-Mental State Examination or the Hamilton Rating Scale for Depression scores.


CONCLUSIONS
This study indicates that decreased perfusion in the frontal cortex is associated with NS severity but not with measures of cognitive impairment or depressive symptoms in DAT patients. These results support the hypothesis that the frontal lobes may be involved in the cause of NS in DAT, and they underscore the importance of NS evaluation in neuroimaging studies.
Galynker
I I
II
Department of Psychiatry, Beth Israel Medical Center, Albert Einstein College of Medicine, New York, New York 10003, USA.
Dutta
E
E
Vilkas
N
N
Ongseng
F
F
Finestone
H
H
Gallagher
R
R
Serseni
D
D
Rosenthal
R N
RN
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000503:physiopathology; D001921:Brain / Q000098:blood supply / Q000503:physiopathology; D003863:Depression / Q000175:diagnosis* / Q000503:physiopathology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D010555:Personality Inventory; D012039:Regional Blood Flow / Q000502:physiology; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
D019690:Technetium Tc 99m Exametazime