Zimmerman M E, Pan J W, Hetherington H P, Katz M J, Verghese J, Buschke H, Derby C A, Lipton R B
Albert Einstein College of Medicine, Saul R. Korey Department of Neurology, 1165 Morris Park Ave., Room 343, Bronx, NY 10461, USA.
Neurology. 2008 Apr 29;70(18):1594-600. doi: 10.1212/01.wnl.0000306314.77311.be. Epub 2008 Mar 26.
Characterization of the behavioral correlates of neuromorphometry and neurochemistry in older adults has important implications for an improved understanding of the aging process. The objective of this study was to test the hypothesis that a measure of hippocampal neuronal metabolism was associated with verbal memory in nondemented older adults after controlling for hippocampal volume.
4-T MRI, proton magnetic resonance spectroscopy ((1)H MRS), and neuropsychological assessment were conducted in 48 older adults (23 women; mean age 81 years). Average hippocampal N-acetyl aspartate/creatine ratios (NAA/Cr) and hippocampal volumes were obtained. Neuropsychological evaluation included tests of verbal memory (Buschke and Grober Free and Cued Selective Reminding Test-Immediate Recall [FCSRT-IR], Wechsler Memory Scale-Revised Logical Memory subtest) and attention and executive function (Trail Making Test Parts A and B).
Linear regression analysis indicated that after adjusting for age, hippocampal NAA/Cr was a significant predictor of FCSRT-IR performance (beta = 0.38, p = 0.01, R (2) = 0.21). Hippocampal volume was also a significant predictor of FCSRT-IR performance after adjusting for age and midsagittal area (beta = 0.47, p = 0.01, R (2) = 0.24). In a combined model, hippocampal NAA/Cr (beta = 0.33, p = 0.03) and volume (beta = 0.35, p = 0.03) were independent predictors of FCSRT-IR performance, accounting for 30% of the variance in memory.
These findings indicate that nondemented older adults with smaller hippocampal volumes and lower levels of hippocampal N-acetyl aspartate/creatine ratio metabolites perform more poorly on a test of verbal memory. The integrity of both the structure and metabolism of the hippocampus may underlie verbal memory function in nondemented elderly.
表征老年人神经形态测量学和神经化学的行为相关性，对于增进对衰老过程的理解具有重要意义。本研究的目的是检验这样一个假设：在控制海马体积后，测量海马神经元代谢与非痴呆老年人的言语记忆相关。
对48名老年人（23名女性；平均年龄81岁）进行了4-T磁共振成像（MRI）、质子磁共振波谱（（1）H MRS）和神经心理学评估。获得了平均海马N-乙酰天门冬氨酸/肌酸比率（NAA/Cr）和海马体积。神经心理学评估包括言语记忆测试（布施克和格罗伯自由及线索选择性回忆测试-即时回忆[FCSRT-IR]、韦氏记忆量表修订版逻辑记忆子测试）以及注意力和执行功能测试（连线测验A和B部分）。
线性回归分析表明，在调整年龄后，海马NAA/Cr是FCSRT-IR表现的显著预测因子（β = 0.38，p = 0.01，R（2） = 0.21）。在调整年龄和正中矢状面面积后，海马体积也是FCSRT-IR表现的显著预测因子（β = 0.47，p = 0.01，R（2） = 0.24）。在一个联合模型中，海马NAA/Cr（β = 0.33，p = 0.03）和体积（β = 0.35，p = 0.03）是FCSRT-IR表现的独立预测因子，占记忆方差的30%。
这些发现表明，海马体积较小且海马N-乙酰天门冬氨酸/肌酸比率代谢物水平较低的非痴呆老年人，在言语记忆测试中的表现更差。海马结构和代谢的完整性可能是非痴呆老年人言语记忆功能的基础。
