Abstract：
Dysphagia represents the main complication of posterior fossa neurosurgery. Adequate diagnosis of this complication is warranted to prevent untimely extubation with subsequent aspiration. Intraoperative neurophysiologic monitoring (IONM) modalities may be used for this purpose. However, it is not known which IONM modality may be significant for diagnosis. This study aimed to define the most significant IONM modality for dysphagia prognostication after posterior fossa neurosurgery.
The analysis included 46 patients (34 with tumors of the fourth ventricle and 12 with brainstem localization) who underwent surgical excision of the tumor. Neurologic symptoms before and after neurosurgery were noted and magnetic resonance imaging with the subsequent volume estimation of the removed mass was performed, followed by an IONM findings analysis (mapping of the nucleus of the caudal cranial nerves [CN] and corticobulbar motor-evoked potentials [CoMEP]).
Aggravation of dysphagia was noted in 24% of the patients, more often in patients with tumor localization in the fourth ventricle (26%) than in those with brainstem mass lesions (16%). Mapping of the caudal cranial nerve nuclei did not correlate with the dysfunction of these structures. CoMEP was significantly associated with the neurologic state of the CN. The decrease in CoMEP is a significant prognostic factor for postoperative bulbar symptoms appearance or aggravation.
Mapping the CN is an important identification tool. The CoMEP modality should be used intraoperatively to determine the functional state of the CN and predict postoperative dysphagia.
The analysis included 46 patients (34 with tumors of the fourth ventricle and 12 with brainstem localization) who underwent surgical excision of the tumor. Neurologic symptoms before and after neurosurgery were noted and magnetic resonance imaging with the subsequent volume estimation of the removed mass was performed, followed by an IONM findings analysis (mapping of the nucleus of the caudal cranial nerves [CN] and corticobulbar motor-evoked potentials [CoMEP]).
Aggravation of dysphagia was noted in 24% of the patients, more often in patients with tumor localization in the fourth ventricle (26%) than in those with brainstem mass lesions (16%). Mapping of the caudal cranial nerve nuclei did not correlate with the dysfunction of these structures. CoMEP was significantly associated with the neurologic state of the CN. The decrease in CoMEP is a significant prognostic factor for postoperative bulbar symptoms appearance or aggravation.
Mapping the CN is an important identification tool. The CoMEP modality should be used intraoperatively to determine the functional state of the CN and predict postoperative dysphagia.
摘要：
目的：吞咽困难是后颅窝神经外科手术的主要并发症。有必要对这种并发症进行充分的诊断，以防止随后误吸而不及时拔管。术中神经生理监测（IONM）模式可用于此目的。然而,尚不清楚哪种IONM模式可能对诊断有意义.这项研究旨在定义后颅窝神经外科手术后吞咽困难预后的最重要IONM方式。
方法：分析包括46例接受手术切除肿瘤的患者（34例第四脑室肿瘤和12例脑干定位）。记录神经外科手术前后的神经系统症状，并进行磁共振成像，随后对切除的肿块进行体积估计。随后进行IONM结果分析(尾颅神经核[CN]和皮质球运动诱发电位[CoMEP]的标测)。
结果：24%的患者出现吞咽困难加重，肿瘤定位在第四脑室的患者（26％）比脑干肿块病变的患者（16％）更常见。尾颅神经核的定位与这些结构的功能障碍无关。CoMEP与CN的神经状态显着相关。CoMEP的减少是术后延髓症状出现或加重的重要预后因素。
结论：定位CN是一个重要的鉴定工具。术中应该使用CoMEP模式来确定CN的功能状态并预测术后吞咽困难。
方法：分析包括46例接受手术切除肿瘤的患者（34例第四脑室肿瘤和12例脑干定位）。记录神经外科手术前后的神经系统症状，并进行磁共振成像，随后对切除的肿块进行体积估计。随后进行IONM结果分析(尾颅神经核[CN]和皮质球运动诱发电位[CoMEP]的标测)。
结果：24%的患者出现吞咽困难加重，肿瘤定位在第四脑室的患者（26％）比脑干肿块病变的患者（16％）更常见。尾颅神经核的定位与这些结构的功能障碍无关。CoMEP与CN的神经状态显着相关。CoMEP的减少是术后延髓症状出现或加重的重要预后因素。
结论：定位CN是一个重要的鉴定工具。术中应该使用CoMEP模式来确定CN的功能状态并预测术后吞咽困难。
