Zimmerman M E, Pan J W, Hetherington H P, Lipton M L, Baigi K, Lipton R B
Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Neurology. 2009 Nov 10;73(19):1567-70. doi: 10.1212/WNL.0b013e3181c0d454.
Few neuroimaging investigations of pain in elderly adults have focused on the hippocampus, a brain structure involved in nociceptive processing that is also subject to involution associated with dementing disorders. The goal of this pilot study was to examine MRI- and magnetic resonance spectroscopy (MRS)-derived hippocampal correlates of pain in older adults.
A subset of 20 nondemented older adults was drawn from the Einstein Aging Study, a community-based sample from the Bronx, NY. Pain was measured on 3 time scales: 1) acute pain right now (pain severity); 2) pain over the past 4 weeks (Short Form-36 Bodily Pain); 3) chronic pain over the past 3 months (Total Pain Index). Hippocampal data included volume data normalized to midsagittal area and N-acetylaspartate to creatine ratios (NAA/Cr).
Smaller hippocampal volume was associated with higher ratings on the Short Form-36 Bodily Pain (r(s) = 0.52, p = 0.02) and a nonsignificant trend was noted for higher ratings of acute pain severity (r(s) = -0.44, p = 0.06). Lower levels of hippocampal NAA/Cr were associated with higher acute pain severity (r(s) = -0.45, p = 0.05). Individuals with chronic pain had a nonsignificant trend for smaller hippocampal volumes (t = 2.00, p = 0.06) and lower levels of hippocampal NAA/Cr (t = 1.71, p = 0.10).
Older adults who report more severe acute or chronic pain have smaller hippocampal volumes and lower levels of hippocampal N-acetylaspartate/creatine, a marker of neuronal integrity. Future studies should consider the role of the hippocampus and other brain structures in the development and experience of pain in healthy elderly and individuals with Alzheimer disease.
针对老年人疼痛的神经影像学研究很少关注海马体，海马体是参与伤害性处理的脑结构，同时也会因痴呆症而发生退化。这项初步研究的目的是检查通过磁共振成像（MRI）和磁共振波谱（MRS）得出的老年人疼痛与海马体的相关性。
从爱因斯坦衰老研究中选取了20名未患痴呆症的老年人作为样本，该研究以纽约布朗克斯区的社区样本为基础。在三个时间尺度上测量疼痛：1）当下的急性疼痛（疼痛严重程度）；2）过去4周的疼痛（简明健康状况调查量表躯体疼痛项）；3）过去3个月的慢性疼痛（总疼痛指数）。海马体数据包括归一化到中矢状面面积的体积数据以及N - 乙酰天门冬氨酸与肌酸的比率（NAA/Cr）。
较小的海马体体积与简明健康状况调查量表躯体疼痛项的较高评分相关（斯皮尔曼等级相关系数r(s) = 0.52，p = 0.02），并且急性疼痛严重程度较高评分存在不显著的趋势（r(s) = -0.44，p = 0.06）。较低的海马体NAA/Cr水平与较高的急性疼痛严重程度相关（r(s) = -0.45，p = 0.05）。患有慢性疼痛的个体海马体体积较小（t = 2.00，p = 0.06）以及海马体NAA/Cr水平较低（t = 1.71，p = 0.10），但均无显著趋势。
报告更严重急性或慢性疼痛的老年人海马体体积较小，且海马体N - 乙酰天门冬氨酸/肌酸水平较低，后者是神经元完整性的标志物。未来的研究应考虑海马体和其他脑结构在健康老年人及阿尔茨海默病患者疼痛发生和体验中的作用。
