The Factors Associated with Typical Pattern of Brain SPECT in Alzheimer's Disease

Kwak, Yong Tae; Han, Il Woo; Bang, Oh Young; Park, Chan H; Koo, Min Seong

Abstract

OBJECTIVES
During the past few years, the development of functional brain imaging techniques has allowed to describe brain impairment in cognitive disorders. Among them, based on the observation of bilateral parietotemporal hypoperfusion in Alzheimer's disease(AD), single photon emission computed tomography(SPECT) is advocated by some as powerful diagnostic tool in the evaluation of demented patients. The aim of this study is to investigate the usefulness of SPECT in the diagnosis of AD and to clarify the associated factors of parietotemporal hypoperfusion, the typical SPECT pattern of Alzheimer's disease(AD).
METHODS
We reviewed the SPECT scans of 26 patients fulfilling NINCDS-ADRDA criteria for probable AD, 14 with typical pattern of SPECT and 12 with atypical pattern of SPECT. Dementia severity was assessed by the Mini-Mental State Examination. Image interpretation was done visually by the consensus opinion of 2 experienced nuclear medicine physicians who were blind to clinical information. To estimate the association of typical pattern of SPECT with other variables of interest, discriminant function analysis was done.
RESULTS
Though the overall diagnostic sensitivity of SPECT in AD was 53.8%, it was 76.9%, in early-onset AD patients. Typical pattern of SPECT was more frequent in the patients with early onset of the symptoms. Duration of symptoms, duration of education, sex, severity of disease was not associated with this SPECT pattern.
CONCLUSION
These findings may be useful in the clinical setting and point to heterogeneity of AD according to age at onset.