Caviness John N
Department of Neurology, Parkinson's Disease and Movement Disorders Center, Mayo Clinic Scottsdale, 13400 East Shea Blvd, Scottsdale, AZ 85259, USA.
Parkinsonism Relat Disord. 2003 Mar;9(4):185-92. doi: 10.1016/s1353-8020(02)00054-8.
Myoclonus is a clinical symptom (or sign) defined as sudden, brief, shock-like, involuntary movements caused by muscular contractions or inhibitions. It may be classified by examination findings, etiology, or physiological characteristics. The main physiological categories for myocolonus are cortical, cortical-subcortical, subcortical, segmental, and peripheral. Neurodegenerative syndromes are potential causes of symptomatic myoclonus. Such syndromes include multiple system atrophy, corticobasal degeneration, progressive supranuclear palsy, frontotemporal dementia and parkinsonism linked to chromosome 17, Huntington's disease, dentato-rubro-pallido-luysian atrophy, Alzheimer's disease, and Parkinson's disease, and other Lewy body disorders. Each neurodegenerative syndrome can have overlapping as well as distinctive clinical neurophysiological properties. However, claims of differentiating between neurodegenerative disorders by using the presence or absence of small amplitude distal action myclonus appear unwarranted. When the myoclonus is small and repetitive, it may not be possible to distinguish it from tremor by phenotypic appearance alone. In this case, clinical neurophysiological offers an opportunity to provide greater differentiation of the phenomenon. More study of the myoclonus in neurodegenerative disease will lead to a better understanding of the processes that cause phenotypic variability among these disorders.
肌阵挛是一种临床症状（或体征），定义为由肌肉收缩或抑制引起的突发、短暂、电击样、不自主运动。它可根据检查结果、病因或生理特征进行分类。肌阵挛主要的生理分类包括皮质性、皮质 - 皮质下性、皮质下性、节段性和周围性。神经退行性综合征是症状性肌阵挛的潜在病因。此类综合征包括多系统萎缩、皮质基底节变性、进行性核上性麻痹、与17号染色体相关的额颞叶痴呆和帕金森综合征、亨廷顿舞蹈病、齿状核 - 红核 - 苍白球 - 路易体萎缩、阿尔茨海默病、帕金森病以及其他路易体疾病。每种神经退行性综合征都可能具有重叠以及独特的临床神经生理特性。然而，通过存在或不存在小幅度远端动作性肌阵挛来区分神经退行性疾病的说法似乎没有依据。当肌阵挛幅度小且重复时，仅通过表型外观可能无法将其与震颤区分开来。在这种情况下，临床神经生理学为更精确地区分这一现象提供了机会。对神经退行性疾病中肌阵挛的更多研究将有助于更好地理解这些疾病中导致表型变异的过程。
