Experimental Neurology Group, Charles Wolfson Clinical Research Facility, Nuffield Department of Clinical Neuroscience, University of Oxford, UK.
Exp Neurol. 2013 Dec;250:104-7. doi: 10.1016/j.expneurol.2013.09.012. Epub 2013 Sep 23.
Tremor represents one of the most prominent examples of aberrant synchronisation within the human motor system, and Essential Tremor (ET) is by far the most common tremor disorder. Yet, even within ET there is considerable variation, and patients may have contrasting amounts of postural and intention tremor. Recently, Pedrosa et al. (2013) challenged tremor circuits in a cohort of patients presenting with ET, by applying low-frequency deep brain stimulation within thalamus. This interventional approach provided strong evidence that distinct (yet possibly overlapping) neural substrates are responsible for postural and intention tremor in ET. Intention tremor, and not postural tremor, was exacerbated by low frequency stimulation, and the effect was localised in the region of the ventrolateral thalamus in such a way as to implicate cerebello-thalamic pathways. These results, taken in conjunction with the contemporary literature, reveal that pathological changes exaggerate oscillatory synchrony in selective components of an extensive and distributed motor network, and that synchronisation within these networks is further regulated according to motor state. Through a combination of pathological and more dynamic physiological factors, activity then spills out into the periphery in the form of tremor. The findings of Pedrosa et al. (2013) are timely as they coincide with an emerging notion that tremor may result through selective dysregulation within a broader tremorgenic network.
震颤是人体运动系统中异常同步的最突出例子之一，而原发性震颤（essential tremor，ET）是迄今为止最常见的震颤障碍。然而，即使在 ET 中，也存在相当大的差异，患者可能有不同程度的姿势性震颤和意向性震颤。最近，Pedrosa 等人（2013 年）通过在丘脑内施加低频深部脑刺激，对表现为 ET 的患者的震颤回路提出了挑战。这种介入方法为 ET 中的姿势性震颤和意向性震颤由不同（但可能重叠）的神经基质负责提供了强有力的证据。意向性震颤而不是姿势性震颤被低频刺激加剧，并且这种效应在丘脑腹外侧区域局部化，从而暗示了小脑-丘脑通路。这些结果与当代文献相结合，表明病理性变化会夸大广泛分布的运动网络中选择性成分的振荡同步性，并且这些网络中的同步性根据运动状态进一步调节。通过病理和更动态的生理因素的结合，活动以震颤的形式溢出到外围。Pedrosa 等人（2013 年）的发现是及时的，因为它们与一种新兴的观点相吻合，即震颤可能是由于更广泛的震颤网络中的选择性失调引起的。
