Ostergaard L, Fuglsang-Frederiksen A, Sjö O, Werdelin L, Winkel H
Department of Neurology, Hvidovre Hospital, University of Copenhagen, Denmark.
Electromyogr Clin Neurophysiol. 1996 Apr-May;36(3):179-85.
Within the latest years botulinum toxin A (BT) applied locally in affected muscles has gained a superior position in the treatment of cervical dystonia. EMG is often used as a guidance for the injections, which has caused a need for better knowledge about the electromyographic changes in the muscles involved. In the present study we used the turns-amplitude analysis for the quantitative evaluation of the EMG of the sternocleidomastoid muscles and posterior neck muscles in 44 patients with cervical dystonia, not previously treated with BT. Twelve healthy subjects were examined for comparison. At rest 13 patients showed abnormal activity (defined as > 100 turns/s) in the sternocleidomastoid muscle contralateral to the involuntary head rotation (CS) and the ipsi- and contralateral posterior neck muscles (IPN and CPN): 12 patients had abnormal activity in CS and IPN, and seven patients had abnormal activity in all muscles, including the ipsilateral sternocleidomastoid muscle (IS). Other combinations were seen less often. The distribution of muscles with abnormal activity was not always obvious from the clinical examination. CPN and IS, i.e., apparently unaffected muscles, showed reduced EMG activity during attempted maximal voluntary contraction, indicating difficulties in activating all motor units.
近年来，局部注射A型肉毒杆菌毒素（BT）在治疗颈部肌张力障碍方面占据了优势地位。肌电图（EMG）常被用作注射的引导，这就需要更好地了解受累肌肉的肌电变化。在本研究中，我们采用匝数-振幅分析对44例未经BT治疗的颈部肌张力障碍患者的胸锁乳突肌和颈后肌的肌电图进行定量评估。选取12名健康受试者作为对照。静息时，13例患者在与非自主头部旋转对侧的胸锁乳突肌（CS）以及同侧和对侧颈后肌（IPN和CPN）中表现出异常活动（定义为>100转/秒）：12例患者CS和IPN有异常活动，7例患者所有肌肉包括同侧胸锁乳突肌（IS）均有异常活动。其他组合较少见。临床检查时，异常活动肌肉的分布并不总是很明显。CPN和IS，即明显未受累的肌肉，在试图进行最大自主收缩时肌电图活动降低，表明激活所有运动单位存在困难。
