SPECT in dementia: clinical and pathological correlation.
BACKGROUND
The clinical diagnosis of dementia continues to be flawed. Although the diagnosis of Alzheimer's disease (AD) is better than 90% at research centers in highly selected patients, the diagnosis of patients with non-AD dementias and atypical AD patients is poor. Single photon emission computed tomography (SPECT) is a functional imaging technique touted as a diagnostic technique for the degenerative disorders. However there have been few clinicopathological studies using SPECT.


METHODS
Twenty-seven consecutive dementia patients were evaluated clinically at a University-based specialty dementia clinic, and a diagnosis of a specific dementia was made. SPECT imaging was used in helping to select a clinical diagnosis. The correlations between clinical, SPECT and autopsy diagnoses were analyzed.


RESULTS
Single photon emission computed tomography predicted pathologic diagnosis in 25 of 27 patients with dementia (92.6%), compared with clinical diagnosis, which was confirmed in 20/27 (74.1%). Distinct patterns were associated with dementia caused by AD, Fronto-Temporal Dementia (FTD), and Jakob-Creutzfeldt Disease (JCD). Vascular insults not seen with computerized tomography (CT) or magnetic resonance imaging (MRI) were found with SPECT. Three different pathologies were found in patients with Parkinsonian-Dementias (PD): Lewy-Body Variant of AD, Diffuse Lewy-bodies without plaques, and substantia nigra neuronal loss without plaques or Lewy-bodies. All showed a temporal-parietal pattern with SPECT that was similar to AD.


CONCLUSIONS
SPECT provides useful positive information in dementia, particularly the differentiation of AD, FTD, and JCD. However, it does not distinguish PD from AD.
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SL
Department of Psychiatry, VA Medical Center, West Los Angeles UCLA School of Medicine 90073, USA.
Miller
B L
BL
Mena
I
I
Kim
R
R
Itabashi
H
H
Darby
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D007562:Creutzfeldt-Jakob Syndrome / Q000000981:diagnostic imaging / Q000473:pathology; D003704:Dementia / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015899:Tomography, Emission-Computed, Single-Photon