Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.
Brain Stimul. 2013 Jul;6(4):582-9. doi: 10.1016/j.brs.2012.12.004. Epub 2013 Jan 4.
Although functional changes in the activation of the cerebellum in Parkinson's disease (PD) patients have been consistently described, it is still debated whether such altered cerebellar activation is a natural consequence of PD pathophysiology or rather it involves compensatory mechanisms.
OBJECTIVE/HYPOTHESIS: We used different forms of cerebellar transcranial magnetic stimulation to evaluate the hypothesis that altered cerebello-cortical interactions can be observed in PD patients and to evaluate the role of dopaminergic treatment.
We studied the effects of a single cerebellar magnetic pulse over the excitability of the contralateral primary motor cortex tested with motor-evoked potentials (MEPs) (cerebellar-brain inhibition-CBI) in a group of 16 PD patients with (ON) and without dopaminergic treatment (OFF), and in 16 age-matched healthy controls. Moreover, we also tested the effects of cerebellar continuous theta-burst stimulation (cTBS) on MEP amplitude, short intracortical inhibition (SICI) and short intracortical facilitation (SICF) tested in the contralateral M1 in 13 PD patients in ON and OFF and in 16 age-matched healthy controls.
CBI was evident in controls but not in PD patients, even when tested in both ON and OFF conditions. Similarly, cerebellar cTBS reduced MEP amplitude and SICI in controls but not in PD patients under any condition.
CONCLUSION(S): These results demonstrate that PD patients have deficient short-latency and long-lasting cerebellar-thalamocortical inhibitory interactions that cannot be promptly restored by standard dopaminergic medication.
尽管帕金森病（PD）患者小脑激活的功能变化已被一致描述，但小脑激活的这种改变是 PD 病理生理学的自然结果，还是涉及代偿机制，仍存在争议。
目的/假设：我们使用了小脑经颅磁刺激的不同形式来评估以下假设，即改变的小脑-皮质相互作用可以在 PD 患者中观察到，并评估多巴胺能治疗的作用。
我们研究了一组 16 名 PD 患者（ON 和 OFF 期）和 16 名年龄匹配的健康对照者，在给予对侧初级运动皮层的运动诱发电位（MEPs）（小脑-脑抑制-CBI）测试时，单个小脑磁脉冲对兴奋性的影响，这些 PD 患者有（ON）和没有（OFF）多巴胺能治疗。此外，我们还测试了小脑连续 theta 爆发刺激（cTBS）对 13 名 ON 和 OFF 期 PD 患者以及 16 名年龄匹配的健康对照者对侧 M1 中 MEPs 振幅、短程内抑制（SICI）和短程内易化（SICF）的影响。
CBI 在对照组中明显，但在 PD 患者中不明显，即使在 ON 和 OFF 两种情况下测试也是如此。同样，小脑 cTBS 在任何情况下都降低了对照组的 MEPs 振幅和 SICI，但对 PD 患者无影响。
这些结果表明，PD 患者存在短暂和长期小脑-丘脑-皮质抑制相互作用的缺陷，而标准的多巴胺能药物治疗不能迅速恢复这种缺陷。
