Evatt Marian L, Freeman Alan, Factor Stewart
Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322, USA.
Handb Clin Neurol. 2011;100:481-511. doi: 10.1016/B978-0-444-52014-2.00037-9.
Dystonia is defined as involuntary sustained muscle contractions producing twisting or squeezing movements and abnormal postures. The movements can be stereotyped and repetitive and they may vary in speed from rapid to slow; sustained contractions can result in fixed postures. Dystonic disorders are classified into primary and secondary forms. Several types of adult-onset primary dystonia have been identified but all share the characteristic that dystonia (including tremor) is the sole neurologic feature. The forms most commonly seen in neurological practice include cranial dystonia (blepharospasm, oromandibular and lingual dystonia and spasmodic dysphonia), cervical dystonia (also known as spasmodic torticollis) and writer's cramp. These are the disorders that benefit most from botulinum toxin injections. A general characteristic of dystonia is that the movements or postures may occur in relation to specific voluntary actions by the involved muscle groups (such as in writer's cramp). Dystonic contractions may occur in one body segment with movement of another (overflow dystonia). With progression, dystonia often becomes present at rest. Dystonic movements typically worsen with anxiety, heightened emotions, and fatigue, decrease with relaxation, and disappear during sleep. There may be diurnal fluctuations in the dystonia, which manifest as little or no involuntary movement in the morning followed by severe disabling dystonia in the afternoon and evening. Morning improvement (or honeymoon) is seen with several types of dystonia. Patients often discover maneuvers that reduce the dystonia and which involve sensory stimuli such as touching the chin lightly in cervical dystonia. These maneuvers are known as sensory tricks, or gestes antagonistes. This chapter focuses on adult-onset focal dystonias including cranial dystonia, cervical dystonia, and writer's cramp. The chapter begins with a review of the epidemiology of focal dystonias, followed by discussions of each major type of focal dystonia, covering clinical phenomenology, differential genetics, and diagnosis. The chapter concludes with discussions of the pathophysiology, the few pathological cases published of adult-onset focal dystonia and management options, and a a brief look at the future.
非自主性的持续性肌肉收缩，产生扭转或挤压动作以及异常姿势。这些动作可以是刻板且重复的，其速度可快可慢；持续性收缩可导致固定姿势。肌张力障碍性疾病分为原发性和继发性。已确定几种成人起病的原发性肌张力障碍类型，但它们都具有肌张力障碍（包括震颤）是唯一神经学特征这一特点。神经科临床最常见的类型包括颅肌张力障碍（睑痉挛、口下颌和舌肌张力障碍以及痉挛性发音障碍）、颈肌张力障碍（也称为痉挛性斜颈）和书写痉挛。这些疾病从肉毒毒素注射中获益最大。肌张力障碍的一个普遍特征是，动作或姿势可能与受累肌肉群的特定自主动作相关（如书写痉挛）。肌张力障碍性收缩可能在一个身体节段出现，而另一个节段运动时也会出现（溢出性肌张力障碍）。随着病情进展，肌张力障碍常出现在静息状态。肌张力障碍性动作通常在焦虑、情绪高涨和疲劳时加重，在放松时减轻，在睡眠中消失。肌张力障碍可能存在日波动，表现为早晨很少或没有非自主性运动，而下午和晚上则出现严重致残性肌张力障碍。几种类型的肌张力障碍都可见早晨病情改善（或蜜月期）。患者常发现一些能减轻肌张力障碍的动作，这些动作涉及感觉刺激，如颈肌张力障碍时轻轻触摸下巴。这些动作被称为感觉技巧或拮抗动作。本章重点关注成人起病的局灶性肌张力障碍，包括颅肌张力障碍、颈肌张力障碍和书写痉挛。本章首先回顾局灶性肌张力障碍的流行病学，随后讨论每种主要类型的局灶性肌张力障碍，涵盖临床现象学、鉴别遗传学和诊断。本章最后讨论病理生理学、已发表的少数成人起病局灶性肌张力障碍的病理病例及治疗选择，并简要展望未来。
