Valls-Solé J, Tolosa E S, Nobbe F, Diéguez E, Muñoz E, Sanz P, Valldeoriola F
Neurology Department, Hospital Clinic, University of Barcelona, Spain.
Mov Disord. 1997 Jul;12(4):576-84. doi: 10.1002/mds.870120415.
We studied 30 patients whose primary complaint was head tremor in an attempt to characterize neurophysiological aspects of their abnormal movement. Based on family medical history and physical examination, 23 patients had definite or probable essential tremor (essential head tremor, EHT). The remaining seven had mild dystonic signs accompanying their head tremor (head tremor plus dystonic signs, HT + DS). We recorded head movement and the electromyographic (EMG) activity of the sternomastoid and splenius capitis muscles, determined the spontaneous blinking rate, and measured the excitability recovery curve of the blink reflex and of the masseteric inhibitory reflex. All patients had tremor bursts at a frequency ranging between 3 and 9 Hz in at least one of the muscles examined. The predominant pattern seen when patients were sitting relaxed and facing forward was that of synchronized EMG bursts in both splenius capitis muscles. Maintenance of extreme head postures demonstrated two types of additional abnormalities: type 1 (enhancement of tremor), which was observed in 11 patients (47.8%) with EHT and in two (28.5%) with HT + DS; and type 2 (activation of neck muscles not required for maintenance of the posture), which was observed in two patients (8.7%) with EHT and in five (71.5%) with HT + DS (chi 2 = 26.4; p < 0.001). Mean blinking rate per minute was 24.9 +/- 14.6 in patients with EHT and 42.3 +/- 10.5 in patients with HT + DS (paired t test, p = 0.001). The blink reflex and masseteric inhibitory reflex excitability recovery curves showed an abnormal interneuronal excitability enhancement in seven (30.4%) of the 23 patients with EHT and in two (28.5%) of the seven with HT + DS (chi 2 = 3.1; p > 0.05). Abnormal patterns of EMG activity of the neck muscles correlated well with the presence of mild dystonic signs. However, the analysis of brainstem interneuronal excitability did not enable recognition of those patients with head tremor who could potentially develop cervical dystonia. The enhancement of brainstem interneuronal excitability found in approximately 30% of patients with head tremor could be related to plastic changes triggered by increased activity of the cranial muscles.
我们研究了30例以头部震颤为主诉的患者，旨在描述其异常运动的神经生理学特征。根据家族病史和体格检查，23例患者患有明确或可能的特发性震颤（特发性头部震颤，EHT）。其余7例患者在头部震颤的同时伴有轻度肌张力障碍体征（头部震颤加肌张力障碍体征，HT + DS）。我们记录了头部运动以及胸锁乳突肌和头夹肌的肌电图（EMG）活动，测定了自发眨眼频率，并测量了眨眼反射和咬肌抑制反射的兴奋性恢复曲线。所有患者在至少一块被检查的肌肉中均出现了频率在3至9 Hz之间的震颤爆发。患者放松地坐着并向前看时，最常见的模式是双侧头夹肌同步EMG爆发。维持极端头部姿势显示出另外两种异常类型：1型（震颤增强），在11例（47.8%）EHT患者和2例（28.5%）HT + DS患者中观察到；2型（维持姿势不需要的颈部肌肉激活），在2例（8.7%）EHT患者和5例（71.5%）HT + DS患者中观察到（χ2 = 26.4；p < 0.001）。EHT患者每分钟平均眨眼频率为24.9±14.6，HT + DS患者为42.3±10.5（配对t检验，p = 0.001）。23例EHT患者中有7例（30.4%）以及7例HT + DS患者中有2例（28.5%）的眨眼反射和咬肌抑制反射兴奋性恢复曲线显示出异常的中间神经元兴奋性增强（χ2 = 3.1；p > 0.05）。颈部肌肉EMG活动的异常模式与轻度肌张力障碍体征的存在密切相关。然而，对脑干中间神经元兴奋性的分析无法识别那些可能发展为颈部肌张力障碍的头部震颤患者。在大约30%的头部震颤患者中发现的脑干中间神经元兴奋性增强可能与颅部肌肉活动增加引发的可塑性变化有关。
