Nardone Raffaele, Höller Yvonne, Thomschewski Aljosha, Kunz Alexander Baden, Lochner Piergiorgio, Golaszewski Stefan, Trinka Eugen, Brigo Francesco
Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University and Center for Cognitive Neuroscience, Salzburg, Austria,
J Neural Transm (Vienna). 2014 Oct;121(10):1313-20. doi: 10.1007/s00702-014-1195-1. Epub 2014 Mar 28.
Short-latency afferent inhibition (SAI) technique gives the opportunity to non-invasively test an inhibitory circuit in the human cerebral motor cortex that depends mainly on central cholinergic activity. Important SAI abnormalities have been reported in both patients with Alzheimer disease (AD) and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a model of "pure" vascular dementia (VD). Interestingly, a normalization of SAI was observed in AD after levo-dopa (L-dopa) administration. We aimed to determine whether the pharmacological manipulation of the dopaminergic system can also interfere with SAI test in CADASIL patients, compared with AD patients and healthy controls. SAI was found to be significantly reduced in both patient groups. L-Dopa significantly increased SAI in the AD patients, while it failed to restore SAI abnormality in CADASIL patients. Therefore, L-dopa-mediated changes on SAI in AD patients seem to be a specific effect. The present study supports the notion that relationship between acetylcholine and dopamine systems may be specifically abnormal in AD. L-Dopa challenge may thus be able to differentiate the patients with AD or a mixed form of dementia from those with "pure" VD.
短潜伏期传入抑制（SAI）技术为非侵入性检测人类大脑运动皮层中主要依赖中枢胆碱能活动的抑制性回路提供了机会。在阿尔茨海默病（AD）患者和伴有皮质下梗死和白质脑病的脑常染色体显性动脉病（CADASIL）患者（一种“纯”血管性痴呆（VD）模型）中均报告了重要的SAI异常。有趣的是，左旋多巴（L-多巴）给药后AD患者的SAI出现了正常化。我们旨在确定与AD患者和健康对照相比，多巴胺能系统的药物操作是否也会干扰CADASIL患者的SAI测试。结果发现两组患者的SAI均显著降低。L-多巴显著增加了AD患者的SAI，但未能恢复CADASIL患者的SAI异常。因此，L-多巴介导的AD患者SAI变化似乎是一种特异性效应。本研究支持了AD中乙酰胆碱和多巴胺系统之间的关系可能存在特异性异常的观点。因此，L-多巴激发试验可能能够将AD患者或混合型痴呆患者与“纯”VD患者区分开来。
