Value of analyzing deep gray matter and occipital lobe perfusion to differentiate dementia with Lewy bodies from Alzheimer's disease.
OBJECTIVE
Dementia with Lewy bodies (DLB) is generally characterized by a decrease in regional cerebral blood flow (rCBF) in the occipital lobe. However, not all patients with DLB have this feature. We explored characteristics of rCBF pattern changes to improve the identification of DLB, in addition to occipital hypoperfusion.


METHODS
The study population comprised 30 patients with probable DLB and 49 patients with probable Alzheimer's disease (AD) who underwent single-photon emission computed tomography. The data were analyzed using Neurological Statistical Image Analysis Software (NEUROSTAT). We established a template of the region of interest (ROI) presenting the parietal lobe, posterior cingulate, striatum, thalamus, and occipital lobe on the standard brain atlas. We then compared the mean Z scores in each ROI between DLB and AD. Moreover, we investigated the value of analyzing relative rCBF changes in both the deep gray matter and occipital lobe in differentiating DLB from AD.


RESULTS
The DLB group showed a significant relative rCBF increase in the bilateral striatum and thalamus, and a significant relative rCBF decrease in the bilateral occipital lobe when compared with the AD group. Receiver-operating characteristic analysis revealed that determining the hyperperfusion in the thalamus together with the hypoperfusion in the occipital lobe enabled a more accurate differentiation between DLB and AD than studying individual areas.


CONCLUSIONS
Studying the relative increase of rCBF in the deep gray matter, and the relative decrease of that in the occipital lobe achieved a high differentiation between DLB and AD. This suggests that determining both an increase and a decrease in rCBF pattern may be important in differentiating between the two diseases.
Shimizu
Soichiro
S
Department of Radiology, Center for Imaging of Neurodegenerative Diseases, Veterans Affairs Medical Center, University of California, San Francisco, 4150 Clement Street, 114M, San Francisco, CA 94121, USA. soichiro.shimizu@radiology.ucsf.edu
Hanyu
Haruo
H
Hirao
Kentaro
K
Sato
Tomohiko
T
Iwamoto
Toshihiko
T
Koizumi
Kiyoshi
K
D000368:Aged; D000465:Algorithms; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D020961:Lewy Body Disease / Q000000981:diagnostic imaging*; D008297:Male; D009474:Neurons / Q000000981:diagnostic imaging*; D009778:Occipital Lobe / Q000098:blood supply / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*