Background: Basal ganglia and thalamus play a central role, via the cortico-basal ganglia-thalamus-cortical loop, in the processing of the neuronal signal from and to the cerebral cortex. Metabolic alterations in the neocortex, causing proportional regional cerebral blood flow (rCBF) changes, affect neuronal signal also in such structures. The aim of this study was to investigate the possibility of using the rCBF of the central structures in discriminating Alzheimer Disease (AD) and Unipolar Depression (UNI) patients from normal controls (CTR). Methods: 47 AD patients, 70 UNI patients and 66 CTR were included in the study. rCBF was assessed by 99m-Tc-HMPAO and using a three-headed gamma camera. A standardised brain atlas was used to define volumes of interest corresponding to nc. caudatus, putamen and thalamus. Analysis of variance (ANOVA) was used to test the significance of the differences in flow and data were covariated for age. Receiver Operating Characteristic (ROC) curves were implemented to evaluate the ability of the rCBF in the different structures to discriminate between the groups. Results: ANOVA showed a significant overall rCBF group difference (p<0.001). As compared to CTR, rCBF in nc. caudatus and thalamus decreased in AD and increased in UNI. The blood flow in putamen was significantly increased only in the CTR/UNI comparison (p<0.001). Thalamus blood flow significantly differed in the CTR/AD (p<0.02) and CTR/UNI (p< 0.001) comparisons. Nc. caudatus blood flow significantly discriminated all three groups (CTR/AD:p<0.001; CTR/UNI: p<0.001; AD/UNI:p<0.01). According to ROC curves, nc. caudatus correctly categorised 74% of the individuals in the CTR-AD group pair and 72% in the CRT-UNI group pair. Conclusions: The blood flow in nc. caudatus and thalamus reflected corresponding changes in cortical regions in both AD and UNI. The decreased perfusion in the temporo-parietal cortex of the AD patients and the increased blood flow in the fronto-temporal cortex of the UNI patients were concomitant in nc. caudatus and thalamus. This is consistent with the anatomical path of the cortico-basal ganglia-thalamus-cortical loop projecting the fronto-temporo-parietal association cortex fibres in a segregated manner to nc. caudatus and thalamus. The putamen receives fibres mainly from motor and pre-motor cortices not involved in AD.
Value of Nucleus Caudatus and Thalamus SPECT rCBF in discriminating among Alzheimer Disease, Unipolar Depression and normal individuals
Pagani M;Salmaso D;
2002
Abstract
Background: Basal ganglia and thalamus play a central role, via the cortico-basal ganglia-thalamus-cortical loop, in the processing of the neuronal signal from and to the cerebral cortex. Metabolic alterations in the neocortex, causing proportional regional cerebral blood flow (rCBF) changes, affect neuronal signal also in such structures. The aim of this study was to investigate the possibility of using the rCBF of the central structures in discriminating Alzheimer Disease (AD) and Unipolar Depression (UNI) patients from normal controls (CTR). Methods: 47 AD patients, 70 UNI patients and 66 CTR were included in the study. rCBF was assessed by 99m-Tc-HMPAO and using a three-headed gamma camera. A standardised brain atlas was used to define volumes of interest corresponding to nc. caudatus, putamen and thalamus. Analysis of variance (ANOVA) was used to test the significance of the differences in flow and data were covariated for age. Receiver Operating Characteristic (ROC) curves were implemented to evaluate the ability of the rCBF in the different structures to discriminate between the groups. Results: ANOVA showed a significant overall rCBF group difference (p<0.001). As compared to CTR, rCBF in nc. caudatus and thalamus decreased in AD and increased in UNI. The blood flow in putamen was significantly increased only in the CTR/UNI comparison (p<0.001). Thalamus blood flow significantly differed in the CTR/AD (p<0.02) and CTR/UNI (p< 0.001) comparisons. Nc. caudatus blood flow significantly discriminated all three groups (CTR/AD:p<0.001; CTR/UNI: p<0.001; AD/UNI:p<0.01). According to ROC curves, nc. caudatus correctly categorised 74% of the individuals in the CTR-AD group pair and 72% in the CRT-UNI group pair. Conclusions: The blood flow in nc. caudatus and thalamus reflected corresponding changes in cortical regions in both AD and UNI. The decreased perfusion in the temporo-parietal cortex of the AD patients and the increased blood flow in the fronto-temporal cortex of the UNI patients were concomitant in nc. caudatus and thalamus. This is consistent with the anatomical path of the cortico-basal ganglia-thalamus-cortical loop projecting the fronto-temporo-parietal association cortex fibres in a segregated manner to nc. caudatus and thalamus. The putamen receives fibres mainly from motor and pre-motor cortices not involved in AD.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
