[Relationship between three neuropsychological tests and cerebral glucose metabolism in Alzheimer's disease].
OBJECTIVE
To study the relationship between the scores of 3 neuropsychological scales: MMSE, extended scale of dementia (ESD) and Blessed dementia scale (BDS) and cerebral glucose metabolism in Alzheimer's disease (AD) indicated by positron emission tomography (PET).


METHODS
Brain scanning was performed with SIEMENS ECAT 47 PET scanner among 21 AD patients, aged 60 - 83 (10 mild, 6 moderate, and 5 severe), and 15 healthy persons, aged 57 - 73. The ratio of mean radioactivity of cerebral lobe to that of cerebellum as semi-quantitative parameters was used to evaluate the cerebral glucose metabolism. Cognitive function was assessed by three neuropsycholigical scales: MMSE, ESD and BDS.


RESULTS
The average MMSE score was 13.3 +/- 6.3 (range 2 - 25), the average ESD score was 120.5 +/- 54.8 (range 28 - 200), and the average BDS score was 4.7 +/- 3.1 (range 0.5 - 10) in the AD patients. The decreases of glucose metabolism in parietal, frontal and temporal lobes were significantly positively correlated with MMSE and ESD scores, and negatively correlated with BDS scores in AD patients (P < 0.05). The correlations between MMSE and ESD (r = 0.886), MMSE and BDS (r = -0.763), and ESD and BDS (r = -0.773) were significant in AD patients (all P < 0.01). Taking the ratio of radioactivity of cerebral lobe to that of cerebellum as an independent variable X, the MMSE, ESD and BDS scorsas dependent variable Y, three regression equations were established as follows: Y = 40.11 * X- 25.32, Y = 309.19 * X- 180.9, Y = 19.97 - 16.53 * X. The independent variable entering the three regression equations was always the ratio of radioactivity of left parietal lobe to that of cerebellum. The ratio of radioactivity of left parietal lobe to that of cerebellum was a significant predictor for cognitive dysfunction measured by MMSE, ESD and BDS in AD patients (P < 0.01).


CONCLUSIONS
MMSE, ESD and BDS scores correlate well with impaired cerebral glucose metabolism in AD. The function of left parietal lobe may play an important role in the progress of the disease. MMSE, ESD and BDS are good measures for cognitive dysfunction.
Zhang
Xin-qing
XQ
Department of Neurology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053, China.
Min
Bao-quan
BQ
Ma
Yun-chuan
YC
Yang
Pei-jie
PJ
Li
De-peng
DP
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism* / Q000523:psychology; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D003071:Cognition; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards; D011569:Psychiatric Status Rating Scales; D014055:Tomography, Emission-Computed
D005947:Glucose