Kamada Chie, Enatsu Rei, Kanno Aya, Ochi Satoko, Yamada Shoto, Sato Ryota, Chiba Ryohei, Mikuni Nobuhiro
Department of Neurosurgery, Sapporo Medical University, Sapporo, Japan.
Department of Neurosurgery, Maronie Street Neurological Clinic, Sapporo, Japan.
Surg Neurol Int. 2023 Sep 1;14:312. doi: 10.25259/SNI_303_2023. eCollection 2023.
Vagal nerve stimulation (VNS) is a palliative treatment for refractory epilepsy and intraoperative nerve stimulation is applied to the vagal and other nerves to prevent electrode misplacement. We evaluated these thresholds to establish intraoperative monitoring procedures for VNS surgery.
Forty-six patients who underwent intraoperative nerve stimulation during VNS placement were enrolled. The vagal nerve and other exposed nerves were electrically stimulated during surgery, and muscle contraction was confirmed by electromyography of the vocal cords and visual recognition of cervical muscle contraction. The nerve thresholds and the most sensitive parts of the vagal nerve were analyzed retrospectively.
The stimulation of vagal nerves induced vocal cord responses in all 46 patients; the median thresholds of the most sensitive parts and all parts were 0.2 mA (range: 0.05-0.75 mA) and 0.25 mA (range: 0.15-1.5 mA), respectively. The medial middle region was identified as the most sensitive part of the vagal nerve in the majority of participants (82.5%). In 11 patients, other cervical nerves were stimulated and sternohyoid muscle contraction was induced with a median threshold of 0.35 mA (range: 0.1-0.7 mA) in eight patients, while sternocleidomastoid muscle contraction was induced with a median threshold of 0.2 mA (range: 0.1-0.2 mA) in three.
Intraoperative stimulation of vagal nerves induces vocal cord responses with locational variations, and the middle part stimulation could minimize the stimulus intensities. The nerves innervating the sternohyoid and sternocleidomastoid muscles may be exposed during the procedure. Knowledge of these characteristics will enhance the effectiveness of this technique in future applications.
迷走神经刺激术（VNS）是一种用于难治性癫痫的姑息治疗方法，术中神经刺激可应用于迷走神经及其他神经以防止电极误置。我们评估了这些阈值，以建立VNS手术的术中监测程序。
纳入46例在VNS植入过程中接受术中神经刺激的患者。手术期间对迷走神经和其他暴露的神经进行电刺激，并通过声带肌电图和颈部肌肉收缩的视觉识别来确认肌肉收缩。回顾性分析神经阈值和迷走神经最敏感部位。
刺激迷走神经在所有46例患者中均诱发了声带反应；最敏感部位和所有部位的中位阈值分别为0.2 mA（范围：0.05 - 0.75 mA）和0.25 mA（范围：0.15 - 1.5 mA）。在大多数参与者（82.5%）中，迷走神经的中内侧区域被确定为最敏感部位。在11例患者中，刺激了其他颈神经，8例患者诱发胸舌骨肌收缩，中位阈值为0.35 mA（范围：0.1 - 0.7 mA），3例患者诱发胸锁乳突肌收缩，中位阈值为0.2 mA（范围：0.1 - 0.2 mA）。
术中刺激迷走神经可诱发声带反应，且存在位置差异，中部刺激可使刺激强度最小化。在此过程中，支配胸舌骨肌和胸锁乳突肌的神经可能会暴露。了解这些特征将提高该技术在未来应用中的有效性。
