Pelosin Elisa, Ogliastro Carla, Lagravinese Giovanna, Bonassi Gaia, Mirelman Anat, Hausdorff Jeffrey M, Abbruzzese Giovanni, Avanzino Laura
Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal Child Health, University of Genoa Genoa, Italy.
Department of Experimental Medicine, Section of Human Physiology and Centro Polifunzionale di Scienze Motorie, University of Genoa Genoa, Italy.
Front Aging Neurosci. 2016 May 9;8:104. doi: 10.3389/fnagi.2016.00104. eCollection 2016.
The aim of this study was to address whether deficits in the central cholinergic activity may contribute to the increased difficulty to allocate attention during gait in the elderly with heightened risk of falls. We recruited 50 participants with a history of two or more falls (33 patients with Parkinson's Disease and 17 older adults) and 14 non-fallers age-matched adults. Cholinergic activity was estimated by means of short latency afferent inhibition (SAI), a transcranial magnetic stimulation (TMS) technique that assesses an inhibitory circuit in the sensorimotor cortex and is regarded as a global marker of cholinergic function in the brain. Increased difficulty to allocate attention during gait was evaluated by measuring gait performance under single and dual-task conditions. Global cognition was also assessed. Results showed that SAI was reduced in patients with PD than in the older adults (fallers and non-fallers) and in older adults fallers with respect to non-fallers. Reduction in SAI indicates less inhibition i.e., less cholinergic activity. Gait speed was reduced in the dual task gait compared to normal gait only in our faller population and changes in gait speed under dual task significantly correlated with the mean value of SAI. This association remained significant after adjusting for cognitive status. These findings suggest that central cholinergic activity may be a predictor of change in gait characteristics under dual tasking in older adults and PD fallers independently of cognitive status.
本研究的目的是探讨中枢胆碱能活性不足是否可能导致跌倒风险较高的老年人在步态过程中分配注意力的难度增加。我们招募了50名有两次或更多次跌倒史的参与者（33例帕金森病患者和17名老年人）以及14名年龄匹配的未跌倒成年人。通过短潜伏期传入抑制（SAI）来估计胆碱能活性，SAI是一种经颅磁刺激（TMS）技术，用于评估感觉运动皮层中的抑制性回路，被视为大脑中胆碱能功能的整体标志物。通过测量单任务和双任务条件下的步态表现来评估步态过程中分配注意力的难度增加情况。还评估了整体认知功能。结果显示，与老年人（跌倒者和未跌倒者）以及未跌倒的老年人相比，帕金森病患者的SAI降低。SAI降低表明抑制作用减弱，即胆碱能活性降低。仅在我们的跌倒者群体中，双任务步态中的步速比正常步态降低，并且双任务下的步速变化与SAI的平均值显著相关。在调整认知状态后，这种关联仍然显著。这些发现表明，中枢胆碱能活性可能是老年人和帕金森病跌倒者在双任务情况下步态特征变化的一个预测指标，且与认知状态无关。
