Bermejo-Pareja Félix, Louis Elan D, Benito-León Julián
Department of Neurology, University Hospital 12 de Octubre, Madrid, Spain.
Mov Disord. 2007 Aug 15;22(11):1573-80. doi: 10.1002/mds.21553.
Essential tremor (ET) is a late-life neurological disease. Mild cognitive deficits as well as an association with prevalent dementia have been reported in recent case-control studies. We determined whether ET was associated with an increased risk of incident dementia. In a population-based study of older people in central Spain (NEDICES), nondemented ET cases and controls were followed prospectively. Incident dementia at follow-up was diagnosed using DSM-IV criteria and the risk of incident dementia was estimated in ET cases versus controls using Cox proportional hazards models. 3,891 participants had a mean duration of follow-up of 3.2 years. Sixteen (7.8%) of 206 ET cases developed incident dementia versus 145 (3.9%) of 3,685 controls (unadjusted relative risk [RR]=2.08, 95% CI=1.24-3.50, P=0.006 and adjusted RR=1.66, 95% CI=0.99-2.80, P=0.054). In an adjusted model, ET cases with tremor onset after age 65 years were twice as likely to develop incident dementia than were controls (RR=1.98, 95% CI=1.14-3.45, P=0.01), whereas ET cases with tremor onset<age 65 years and controls were equally to develop incident dementia (RR=0.74, 95% CI=0.19-3.20, P=0.79). Although ET is often considered a benign condition, in this prospective, population-based study, elderly-onset ET was associated with an increased risk of incident dementia. The basis for this dementia, which is not known, requires additional study.
特发性震颤（ET）是一种老年期神经疾病。近期病例对照研究报告了其存在轻度认知缺陷以及与常见痴呆症的关联。我们确定了ET是否与新发痴呆症风险增加相关。在西班牙中部一项针对老年人的基于人群的研究（NEDICES）中，对未患痴呆症的ET病例和对照进行了前瞻性随访。随访时的新发痴呆症根据《精神疾病诊断与统计手册》第四版（DSM-IV）标准进行诊断，并使用Cox比例风险模型估计ET病例与对照相比新发痴呆症的风险。3891名参与者的平均随访时长为3.2年。206例ET病例中有16例（7.8%）发生了新发痴呆症，而3685例对照中有145例（3.9%）发生了新发痴呆症（未调整相对风险[RR]=2.08，95%置信区间[CI]=1.24 - 3.50，P = 0.006；调整后RR = 1.66，95% CI = 0.99 - 2.80，P = 0.054）。在一个调整模型中，65岁以后出现震颤的ET病例发生新发痴呆症的可能性是对照的两倍（RR = 1.98，95% CI = 1.14 - 3.45，P = 0.01），而65岁之前出现震颤的ET病例和对照发生新发痴呆症的可能性相同（RR = 0.74，95% CI = 0.19 - 3.20，P = 0.79）。尽管ET通常被认为是一种良性疾病，但在这项基于人群的前瞻性研究中，老年期发病的ET与新发痴呆症风险增加相关。这种痴呆症的病因尚不清楚，需要进一步研究。
