Regional cerebral metabolism in early Alzheimer's disease with clinically significant apathy or depression.
BACKGROUND
Alzheimer's disease (AD) is clinically characterized by cognitive impairment and behavioral disturbances. The aim of the study was to identify regional alterations in brain function associated with neuropsychiatric symptoms in early AD.


METHODS
Patients underwent measures of cerebral glucose metabolism applying positron emission tomography (PET) and (18)F-fluorodeoxyglucose. Neuropsychiatric symptoms were assessed using the Neuropsychiatric Inventory (NPI). Positron emission tomography images of patients suffering a neuropsychiatric symptom of clinical significance (NPI subscore for a specific item >/=4 points) were compared with the images of patients without the specific symptom under study (NPI subscore for a specific item = 0 points).


RESULTS
A total of 53 patients with AD (Mini-Mental State Examination [MMSE] 22.5 +/- 2.94 points) entered the study. Of all symptoms, apathy and depression were most frequently encountered. The patient group with apathy (n = 17) revealed significant decreases in left orbitofrontal regions when compared with patients free of apathy. Depression of clinical significance (n = 10) was associated with hypometabolism in dorsolateral prefrontal regions.


CONCLUSIONS
These findings support the notion that different functional circuits underlie apathy and depression in early AD.
Holthoff
Vjera A
VA
Department of Psychiatry and Psychotherapy, Dresden University of Technology, Germany.
Beuthien-Baumann
Bettina
B
Kalbe
Elke
E
Lüdecke
Susanne
S
Lenz
Olaf
O
Zündorf
Gerhard
G
Spirling
Sebastian
S
Schierz
Kristin
K
Winiecki
Peter
P
Sorbi
Sandro
S
Herholz
Karl
K
D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003710:Demography; D003863:Depression / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D049292:Leukoaraiosis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D049268:Positron-Emission Tomography / Q000379:methods; D011569:Psychiatric Status Rating Scales