Department of Neurology, Karadeniz Technical University School of Medicine, 61080, Trabzon, Turkey.
Outpatient Electromyography Laboratory, Istanbul Training and Research Hospital, 34098, Istanbul, Turkey.
Acta Neurol Belg. 2020 Jun;120(3):609-613. doi: 10.1007/s13760-018-0889-9. Epub 2018 Feb 10.
Repetitive nerve stimulation (RNS) is a highly sensitive electrophysiological test used for diagnosing myasthenia gravis (MG). Here, we evaluated electrodiagnostic value of RNS using facial nerve and occipitalis muscle. Patients with generalized MG were included. Clinical findings were assessed. RNS test was performed on occipitalis, nasalis, trapezius, abductor policis brevis (APB) and abductor digiti minimi (ADM) muscles. Twenty-five (78%) patients had relevant decrement during RNS test of at least one muscle. Nasalis muscle had the highest diagnostic potential (68.8%), followed by trapezius (53.3%), occipitalis (50%), APB (30%) and ADM (16.7%) muscles. There was not a significant relationship between clinical symptoms and facial RNS recorded on occipitalis muscle. In conclusion, we suggest that facial RNS recording over occipitalis muscle can be added in electrodiagnosis of MG because of cranial nerve innervation and proximal location. Facial RNS recording over occipitalis muscle provides a good choice under the conditions such as atrophy, cosmetic surgery, or botulinum toxin application in which nasalis muscle is unavailable for use.
重复神经电刺激（RNS）是一种高度敏感的电生理测试，用于诊断重症肌无力（MG）。在这里，我们评估了面神经和枕肌的 RNS 电诊断价值。纳入了全身性 MG 患者。评估了临床发现。对面神经、鼻肌、斜方肌、拇指外展短肌（APB）和小指外展肌（ADM）进行了 RNS 测试。25 名（78%）患者在至少一种肌肉的 RNS 测试中出现相关递减。鼻肌具有最高的诊断潜力（68.8%），其次是斜方肌（53.3%）、枕肌（50%）、APB（30%）和 ADM（16.7%）肌肉。面神经和枕肌上的 RNS 记录之间的临床症状没有显著关系。总之，我们建议在 MG 的电诊断中增加枕肌上的面神经 RNS 记录，因为面神经支配颅神经和枕肌的近端位置。在鼻肌无法使用的情况下，如肌肉萎缩、整容手术或肉毒毒素应用等情况下，枕肌上的面神经 RNS 记录提供了一个很好的选择。
