Dystonia is a heterogeneous group of hyperkinetic movement disorders. The unifying descriptor of dystonia is the motor manifestation, characterized by continuous or intermittent contractions of muscles that cause abnormal movements and postures. Additionally, there are psychiatric, cognitive, and sensory alterations that are possible or putative non-motor manifestations of dystonia. The pathophysiology of dystonia is incompletely understood. A better understanding of dystonia pathophysiology is highly relevant in the amelioration of significant disability associated with motor and non-motor manifestations of dystonia. Recently, diminished olfaction was found to be a potential non-motor manifestation that may worsen the situation of subjects with dystonia. Yet, this finding may also shed light into dystonia pathophysiology and yield novel treatment options. This article aims to provide background information on dystonia and the current understanding of its pathophysiology, including the key structures involved, namely, the basal ganglia, cerebellum, and sensorimotor cortex. Additionally, involvement of these structures in the chemical senses are reviewed to provide an overview on how olfactory (and gustatory) deficits may occur in dystonia. Finally, we describe the present findings on altered chemical senses in dystonia and discuss directions of research on olfactory dysfunction as a marker in dystonia.

中文翻译：

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嗅觉作为肌张力障碍的标志物：背景，现状和方向

肌张力障碍是一组异种运动亢进症。肌张力障碍的统一描述是运动表现，其特征在于肌肉的连续或间歇性收缩，引起异常的运动和姿势。此外，还有精神病，认知和感觉改变，可能是肌张力障碍的可能表现或非运动表现。对肌张力障碍的病理生理尚未完全了解。对肌张力障碍病理生理的更好理解与缓解与肌张力障碍的运动和非运动表现相关的严重残疾高度相关。最近，嗅觉下降是潜在的非运动表现，可能会使肌张力障碍患者的状况恶化。然而，这一发现也可能为肌张力障碍的病理生理学提供启示，并产生新的治疗选择。本文旨在提供有关肌张力障碍的背景信息以及对肌张力障碍的病理生理学的当前了解，包括所涉及的关键结构，即基底神经节，小脑和感觉运动皮层。另外，对这些结构在化学意义上的参与进行了综述，以概述肌张力障碍中嗅觉（和味觉）缺陷的发生方式。最后，我们描述了肌张力障碍中化学感觉改变的当前发现，并讨论了嗅觉功能障碍作为肌张力障碍标记的研究方向。和感觉运动皮层。另外，对这些结构在化学意义上的参与进行了综述，以概述肌张力障碍中嗅觉（和味觉）缺陷的发生方式。最后，我们描述了目前在肌张力障碍中化学感觉改变的发现，并讨论了嗅觉障碍作为肌张力障碍标记的研究方向。和感觉运动皮层。此外，对这些结构在化学意义上的参与进行了综述，以概述肌张力障碍中嗅觉（和味觉）缺陷的发生方式。最后，我们描述了目前在肌张力障碍中化学感觉改变的发现，并讨论了嗅觉障碍作为肌张力障碍标记的研究方向。