ABNORMAL HEAD MOVEMENTS
ABNORMAL HEAD MOVEMENTS
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DOI：
10.1136/jnnp.42.8.705
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发表时间：
1979-01-01
影响因子：
11
通讯作者：
HALMAGYI, GM
中科院分区：
文献类型：
--
作者：
GRESTY, MA;HALMAGYI, GM
使用客观记录技术研究了各种疾病中的异常头部运动，并对运动频率内容的数据进行了分析。抽动、点头、抽动、舞蹈、肌阵挛抽搐和大多数头部震颤涉及大约2和4赫兹的频率，这与头部的自然基频和二次谐波共振相对应，这是由头颈部系统的机械特性决定的。这些发现为异常头部运动的分类和解释颈部肌肉张力不足引起的异常头部运动的特征提供了基础。震颤频率和自然共振之间的相似性表明，在头部的情况下，震颤是由神经机制的紊乱引起的，神经机制通常负责对头部自主运动的精细控制，以及在姿势紊乱时头部的稳定。先天性眼球震颤的头部运动可分为两种类型。有些波形怪异，没有辅助视力，被认为是主要的病理起源，归类为震颤。另一些是习得的适应性反应，通过打断眼球震颤来辅助视力，比如在痉挛的情况下，或者通过用反波形来补偿眼球震颤，被称为点头。真正代偿性点头的先决条件是前庭-眼反射的改变。
Abnormal head movements were studied in a variety of diseases using objective recording techniques and the data analyzed with respect to the frequency content of the movement. Flopping, nodding, tic, chorea, myoclonic jerks and most head tremors involve frequencies of approximately 2 and 4 Hz which correspond to the natural fundamental and 2nd harmonic resonances of the head as determined by the mechanical properties of the head/neck system. These findings provide a basis for both classification of abnormal head movements and an explanation of the characteristics of those arising from hypotonia of the neck muscles. The similarities between tremor frequencies and natural resonances suggest that in the case of the head, tremor arises from disorders of neural mechanisms normally responsible for the fine control of voluntary head movement and for stabilization of the head during disturbance of posture. Head movements in cases of congenital nystagmus were found to be of 2 types. Some were of bizarre waveform, in no way assisted vision and were taken to be of primarily pathological origin and classified as tremors. Others were learned adaptive responses which assisted vision either by interrupting the nystagmus, as in the case of spasmus nutans, or by compensating for the nystagmus with an inverse waveform and were called nodding. A prerequisite for true compensatory nodding is modified vestibulo-ocular reflex.