Université Lille-Nord de France, CHRU de Lille, Neurophysiologie Clinique, Hôpital Roger Salengro, F-59037 Lille Cedex, France.
Neurosci Lett. 2011 Jul 12;498(3):208-12. doi: 10.1016/j.neulet.2011.05.010. Epub 2011 May 11.
Sensorimotor performance declines with normal aging. The present study explored age-related changes in sensorimotor integration by conditioning a supra-threshold transcranial magnetic stimulation pulse with a peripheral nerve shock at different interstimulus intervals. Cortical motor threshold of the abductor pollicis brevis muscle, intracortical inhibition and facilitation were measured. We also assessed the influence of median nerve stimulation on motor cortex excitability at intervals which evoked short- and long-latency afferent inhibition (SAI and LAI, respectively) and afferent-induced facilitation (AIF). We observed a marked decrease of the long latency influence of proprioceptive inputs on M1 excitability in the elderly, with the loss of AIF and LAI. The SAI, motor thresholds and intracortical inhibition and facilitation were not age-related. Decreased sensorimotor performance with aging appears to be associated with a decrease in the influence of proprioceptive inputs on motor cortex excitability at longer intervals (probably via higher order cortical areas).
随着正常衰老，感觉运动表现会下降。本研究通过在不同的刺激间隔下用外周神经冲击条件化超阈值经颅磁刺激脉冲，来探索感觉运动整合的年龄相关性变化。测量了拇短展肌的皮质运动阈值、皮质内抑制和易化。我们还评估了在分别引起短潜伏期传入抑制（SAI）和长潜伏期传入抑制（LAI）以及传入诱导易化（AIF）的间隔刺激正中神经对运动皮层兴奋性的影响。我们观察到老年人对 M1 兴奋性的本体感觉传入的长潜伏期影响明显下降，丧失了 AIF 和 LAI。SAI、运动阈值以及皮质内抑制和易化与年龄无关。随着年龄的增长，感觉运动表现的下降似乎与较长时间间隔上本体感觉传入对运动皮层兴奋性的影响降低有关（可能通过更高阶的皮层区域）。
