ISSN:
1619-7089
Keywords:
Dementia with Lewy bodies
;
Alzheimer's disease
;
D2 receptors
;
Iodine-123 iodobenzamide
;
Single-photon emission tomography
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Dementia with Lewy bodies (DLB) can at present only be diagnosed with certainty by neuropathological examination. Diagnosis during life remains at best probable, based on the presence of symptoms known from autopsy studies to be frequently associated with DLB. The greatest practical clinical problem lies in distinguishing DLB arid Alzheimer's disease (AD). In DLB there is a considerable degeneration of nigral neurones with depletion of striatal dopamine. In contrast, AD is not associated with significant changes in dopamine metabolism. Iodine-123 iodobenzamide single-photon emission tomography (IBZM-SPET) measures post-synaptic dopamine D2 neuroreceptor availability in the corpus striatum, but is nevertheless a method for assessing the integrity of the nigrostriatal dopaminergic pathway. Sixteen clinically diagnosed DLB patients, 15 normal controls arid 13 AD patients underwent IBZM-SPET. All subjects were scanned 1.5–2 h after intravenous injection of 185 MBq of123I-IBZM. Circular regions of iriterest were employed to calculate radioactivity ratios in each hemisphere as follows: caudate nucleus/frontal cortex, putamen/frontal cortex arid caudate nucleus/putamen. The DLB patients had significantly lower left caudate/putamen ratios (95% confidence intervals: DLB 0.893–0.965, AD 0.972–1.175, controls 1.031–1.168) than either controls or AD patients, and significantly lower right caudate/putamen ratios (95% confidence intervals: DLB 0.926–1.019, AD 0.954–1.103, controls 1.027–1.144) chan controls. Our data suggest that patients with DLB diagnosed by clinical criteria have changes in striatal post-synaptic D2 receptors. This may be of value in distinguishing DLB from AD during life.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00841397
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