[Relationship between SPECT and pathological alterations in Alzheimer's disease--a study of a case with left-hemisphere dominant lesions].
123I-IMP SPECT (SPECT) has been widely used in clinical neuropsychiatry for establishing the clinical diagnosis, and evaluating the course of the disease. However, little is known about the significance of alterations in SPECT. In this paper, we present comparative study between alterations in SPECT and neuropathological findings in the case of Alzheimer's disease (AD). The patient, a 59-year-old female, began to show memory disturbance and the left hemisphere disturbances, non-fluent aphasia, but right hemisphere disturbances, constructional apraxia, visuo-spatial dysfunctions were not notable at the early stage. The neuroimaging also revealed left-side dominant cerebral atrophy in MRI and left-side dominant hypoactive regions in SPECT (especially in parietal lobe). Memory disturbance and non-fluent aphasia gradually progressed after admission. Then, mirror phenomenon and Bálint's syndrome appeared at the age of 63 years. In the advanced stage, hypoactive regions in SPECT were expanded into temporal and frontal areas. The laterality observed at the early stage became unremarkable. The patient died from heart failure at 64 years. Pathological diagnosis was AD. Eleven ROI (region of interests) were determined on each hemisphere in transverse SPECT image. We calculated ROI% (each ROI count/ROI count at central cerebellum). Neuronal cell count (NCC) and amyloid beta protein deposited areas (BDA) were estimated using 3 serial sections stained with Nissl's method and immunostained for amyloid using monoclonal antibody raised against synthetic A beta, mcAb 90/12. Digitized images based on photographs were analyzed with NIH-image 1.45. NCC decreased in number in frontal, temporal, and parietal lobes. Significant asymmetrical reduction of NCC (lt. < rt.) was observed in orbital, superior temporal and angular gyri (p < 0.01). BDA in superior parietal lobule, superior temporal gyrus and superior, middle, inferior frontal gyri were larger than those in precentral gyrus and visual cortex. Asymmetry of BDA (lt. > rt.) was significant in middle temporal gyrus (p < 0.01). ROI% at the early stage was correlated with corresponding NCC (r = 0.49, p < 0.05) and BDA (r = -0.55, p < 0.01), but at the advanced stage was not significantly correlated with corresponding NCC (r = 0.26) and BDA (r = -0.20). It is evident that SPECT shows good correlation with clinical features and pathological alterations during the course of AD. Our observations imply that the changes in SPECT usually precede the appearance of the clinical symptoms. SPECT is very sensitive in detecting the functional decline in certain regions of the CNS. In the case of AD, the hypoactive regions in SPECT at the early stage may indicate functional decline of the neuronal cells, and at the advanced stage, these may indicate the degree of pathological changes, especially neuronal loss and amyloid beta protein deposition.
Department of Neuropsychiatry, School of Medicine, Sapporo Medical University.
N
N
Nakano
R
R
Fukatsu
M
M
Fujii
J
J
Miyazawa
K
K
Utsumi
S
S
Hayashi
Y
Y
Midorikawa
K
K
Tsuzuki
N
N
Takahata
D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology*; D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon