目的:有症状的ChiariI畸形的手术治疗包括颅颈交界处的手术减压。鉴于关键脑干结构的接近,术中神经监测(IONM)在某些机构中用于安全减压。然而,IONM增加了操作的时间和成本,对患者的益处尚未确定。鉴于外科手术的多样性,关于何时使用IONM以及哪种方式最有用,目前尚无循证护理标准.这项研究的目的是回顾一个单一的外科医生与IONM的经验,以确定的敏感性,特异性,以及儿科ChiariI减压中常规使用的各种IONM模式的预测价值;检查患者之间的关联,临床,和影像学特征和IONM警报;并在手术过程中获取有关这些方式的有用性的数据,以改善患者的预后。
方法:对300例连续的儿科患者进行回顾性分析,这些患者接受了枕下颅骨切除术和C1椎板切除术,由一名外科医生进行Chiari减压,为期15年。临床,射线照相,并收集IONM数据。颅底形态异常的射线照相测量,包括斜角,张伯伦的台词,和Grabb-Oakes生产线,在有和没有真正的IONM信号变化的患者之间进行比较。
结果:共291例,年龄范围为6个月至19岁。在291例病例中,291监测体感诱发电位(SSEP),209监测运动诱发电位(MEP),290监测颅神经自发肌电图(sEMG),110监测脑干听觉诱发电位(BAEP)。灵敏度,特异性,正预测值,和阴性预测值,分别,如下:SSEP的1.00、1.00、1.00和1.00;MEP的1.00、0.99、0.67和1.00;sEMG的0.00、0.88、0.00和1.00;不可应用,1.00,不适用,BAEP为1.00。6例患者有真正的IONM信号变化。这些患者有放射学证据表明更严重的合并颅颈不稳定和基底内陷,具有更陡的斜角(124°对146°,p=0.02)和更大的Grabb-Oakes线(10.1mm对6.7mm,p=0.02),与没有任何真实IONM变化的患者相比。
结论:术中神经监测可能最好用于显示颅底形态异常的影像学特征的患者,定义为平角<135°或Grabb-Oakes线>9mm。当使用IONM时,SSEP和MEP监测是最有用的方式。
Surgical treatment for symptomatic Chiari I malformation involves surgical decompression of the craniovertebral junction. Given the proximity of critical brainstem structures, intraoperative neuromonitoring (IONM) is employed for safe decompression in some institutions. However, IONM adds time and cost to the operation, and the benefit to the patient has not been defined. Given the diversity in surgical practices, there is no evidence-based standard of care regarding when to use IONM and which modalities are most helpful. The purpose of this study was to review a single-surgeon experience with IONM in order to determine the sensitivity, specificity, and predictive values of various IONM modalities routinely used in pediatric Chiari I decompression; to examine the associations between patient, clinical, and radiographic characteristics and IONM alerts; and to obtain data regarding the usefulness of these modalities during the surgical process to improve patient outcomes.
A retrospective review was performed for 300 consecutive pediatric patients who underwent suboccipital craniectomy and C1 laminectomy for Chiari decompression performed by a single surgeon over a 15-year period. Clinical, radiographic, and IONM data were collected. Radiographic measurements of the skull base morphological abnormalities, including clival angle, Chamberlain\'s line, and Grabb-Oakes line, were compared between patients with and without true IONM signal changes.
A total of 291 cases were included, with an age range of 6 months to 19 years. Among 291 cases, somatosensory evoked potentials (SSEPs) were monitored in 291, motor evoked potentials (MEPs) in 209, cranial nerve spontaneous electromyography (sEMG) in 290, and brainstem auditory evoked potentials (BAEPs) in 110. Sensitivity, specificity, positive predictive value, and negative predictive value, respectively, were as follows: 1.00, 1.00, 1.00, and 1.00 for SSEPs; 1.00, 0.99, 0.67, and 1.00 for MEPs; 0.00, 0.88, 0.00, and 1.00 for sEMG; and not appliable, 1.00, not applicable, and 1.00 for BAEPs. Six patients had true IONM signal changes. These patients had radiographic evidence of more severe concomitant craniocervical instability and basilar invagination, with steeper clival angles (124° vs 146°, p = 0.02) and larger Grabb-Oakes lines (10.1 mm vs 6.7 mm, p = 0.02), when compared with the patients without any true IONM changes.
Intraoperative neuromonitoring may be best utilized for patients who show radiographic features of abnormal skull base morphology, defined as a clival angle < 135° or Grabb-Oakes line > 9 mm. When IONM is employed, SSEP and MEP monitoring are the most useful modalities.