Objective: To identify features in cognitive functioning and regional cerebral blood flow (rCBF) in newly diagnosed Parkinson’ s disease (PD) patients and to determine whether these factors are able to predict the pr...Objective: To identify features in cognitive functioning and regional cerebral blood flow (rCBF) in newly diagnosed Parkinson’ s disease (PD) patients and to determine whether these factors are able to predict the progression of the disease in general and the development of cognitive decline in particular. Methods: 50 previously treatment- naive PD patients participated in the study. Cognitive assessment and SPECT were performed twice: at the time of diagnosis and then 3 years later. Six patients died or refused to continue. The Mattis dementia rating scale, the WAIS- R digit span test, a word list learning/recall test, a word fluency task and the Stroop word- colour test were used to assess cognitive function. rCBF was measured in 10 pairs of regions of interest. Principal component analysis of the data from the final examination was used to determine which variables allowed the formation of patient subgroups. Thereafter, factorial discriminant analysis (FDA) was performed in order to obtain a predictive model of these final classes. Results: A stepwise procedure enabled the identification of 3 clusters (26, 16 and 2 patients). As the patients in the smallest cluster met the criteria for dementia at the final examination, they were discarded from further analyses. All the cognitive variables contributed to the constitution of the two other clusters. Age, educational level and all the rCBF parameters also contributed but to a lesser extent. Comparison of these groups showed reduced overall cognitive efficiency and an exacerbated subcorticofrontal syndrome in the 16- patient cluster. FDA showed that the best predictive model for the final classes was based on 7 variables: educational level, semantic and alternating word fluency, Stroop interference index and the right medial frontal, left parietal and left lenticular nucleus rCBF findings. Conclusion: Even though both cognitive and rCBF parameters help predict the progression of newly diagnosed PD patients and bearing in mind the limitations of the SPECT method used here, it appears that the contribution of cognitive assessment is greater than that of rCBF measurement.展开更多
We investigated whether brain SPECT findings show any differences between pat ients with mild and moderate Alzheimer’ s disease (AD) and to compare results w ith event related potentials (ERPs). Twenty- two patients ...We investigated whether brain SPECT findings show any differences between pat ients with mild and moderate Alzheimer’ s disease (AD) and to compare results w ith event related potentials (ERPs). Twenty- two patients with mild to moderate AD diagnosed according to NINCDS- ADRDA criteria and 10 age- matched control subjects were included in this prospective study. All subjects underwent ERP rec ordings and Tc- 99m HMPAO brain SPECT study. Cortical perfusion index (CPI)- w as calculated as the ratio of cortical activity to the cerebellum activity. CPI was found to be statistically lower in bilaterally posterolateral temporal corte x and precuneus in the moderate AD compared to the control group. There was no s tatistically significant difference between the mild AD and control groups for C PI in any cortical areas. The mean P300 latency was statistically prolonged in t he mild and moderate AD compared to the control group. In addition, in moderate AD P300 latency was longer than in mild AD. While the mean P300 amplitude was st atistically reduced in moderate AD compared to the control and mild AD, there wa s no statistically significant difference between the mild AD and control groups . There was a strong negative correlation between P300 latency and CPI in the ri ght and left precuneus in the moderate AD group. The present study suggested tha t Tc- 99m HMPAO SPECT study is the more appropriate technique for patients with moderate AD rather than mild AD. Our results indicated that alterations in ERPs , especially prolongation of P300 latency could be a finding that occurred earli er than the deterioration in cerebral blood flow. We thought that precuneus is c losely related to cognitive function and may have an important role in the patho physiology of AD.展开更多
文摘Objective: To identify features in cognitive functioning and regional cerebral blood flow (rCBF) in newly diagnosed Parkinson’ s disease (PD) patients and to determine whether these factors are able to predict the progression of the disease in general and the development of cognitive decline in particular. Methods: 50 previously treatment- naive PD patients participated in the study. Cognitive assessment and SPECT were performed twice: at the time of diagnosis and then 3 years later. Six patients died or refused to continue. The Mattis dementia rating scale, the WAIS- R digit span test, a word list learning/recall test, a word fluency task and the Stroop word- colour test were used to assess cognitive function. rCBF was measured in 10 pairs of regions of interest. Principal component analysis of the data from the final examination was used to determine which variables allowed the formation of patient subgroups. Thereafter, factorial discriminant analysis (FDA) was performed in order to obtain a predictive model of these final classes. Results: A stepwise procedure enabled the identification of 3 clusters (26, 16 and 2 patients). As the patients in the smallest cluster met the criteria for dementia at the final examination, they were discarded from further analyses. All the cognitive variables contributed to the constitution of the two other clusters. Age, educational level and all the rCBF parameters also contributed but to a lesser extent. Comparison of these groups showed reduced overall cognitive efficiency and an exacerbated subcorticofrontal syndrome in the 16- patient cluster. FDA showed that the best predictive model for the final classes was based on 7 variables: educational level, semantic and alternating word fluency, Stroop interference index and the right medial frontal, left parietal and left lenticular nucleus rCBF findings. Conclusion: Even though both cognitive and rCBF parameters help predict the progression of newly diagnosed PD patients and bearing in mind the limitations of the SPECT method used here, it appears that the contribution of cognitive assessment is greater than that of rCBF measurement.
文摘We investigated whether brain SPECT findings show any differences between pat ients with mild and moderate Alzheimer’ s disease (AD) and to compare results w ith event related potentials (ERPs). Twenty- two patients with mild to moderate AD diagnosed according to NINCDS- ADRDA criteria and 10 age- matched control subjects were included in this prospective study. All subjects underwent ERP rec ordings and Tc- 99m HMPAO brain SPECT study. Cortical perfusion index (CPI)- w as calculated as the ratio of cortical activity to the cerebellum activity. CPI was found to be statistically lower in bilaterally posterolateral temporal corte x and precuneus in the moderate AD compared to the control group. There was no s tatistically significant difference between the mild AD and control groups for C PI in any cortical areas. The mean P300 latency was statistically prolonged in t he mild and moderate AD compared to the control group. In addition, in moderate AD P300 latency was longer than in mild AD. While the mean P300 amplitude was st atistically reduced in moderate AD compared to the control and mild AD, there wa s no statistically significant difference between the mild AD and control groups . There was a strong negative correlation between P300 latency and CPI in the ri ght and left precuneus in the moderate AD group. The present study suggested tha t Tc- 99m HMPAO SPECT study is the more appropriate technique for patients with moderate AD rather than mild AD. Our results indicated that alterations in ERPs , especially prolongation of P300 latency could be a finding that occurred earli er than the deterioration in cerebral blood flow. We thought that precuneus is c losely related to cognitive function and may have an important role in the patho physiology of AD.
