Neurophysiological monitoring of the laryngeal adductor reflex during cerebellar-pontine angle and brainstem surgery. Issue 2 (February 2021)

• Record Type: Journal Article
• Authors: Téllez, Maria J.; Mirallave-Pescador, Ana; Seidel, Kathleen; Urriza, Javier; Shoakazemi, Alireza; Raabe, Andreas; Ghatan, Saadi; Deletis, Vedran; Ulkatan, Sedat
• Is Part Of: Clinical neurophysiology. Volume 132:Issue 2(2021)
• Page Start: 622
• Page End: 631
• Publication Date: 2021-02
• Subjects: Brainstem -- Tumor -- Posterior fossa -- Surgery -- Complications -- Neurophysiological monitoring; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2020.10.021
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Laryngeal adductor reflex (LAR) loss or decrement correlates with laryngeal dysfunction after posterior fossa and brainstem surgery. The LAR provides a functional assessment of the sensory and motor fibers/nuclei of vagus nerve and reflexive medullary pathways. Continuous monitoring of the LAR, together with vocal corticobulbar motor evoked potentials, may enhance safety to resect complex posterior fossa and brainstem lesions. Abstract: Objective: To correlate intraoperative changes of the laryngeal adductor reflex (LAR), alone or in combination with corticobulbar motor evoked potential of vocal muscles (vocal-CoMEPs), with postoperative laryngeal function after posterior fossa and brainstem surgery. Methods: We monitored 53 patients during cerebellar-pontine angle and brainstem surgeries. Vocal-CoMEPs and LAR were recorded from an endotracheal tube with imbedded electrodes or hook-wires electrodes. A LAR significant change (LAR-SC) defined as ≥ 50% amplitude decrement or loss, was classified as either transient or permanent injury to the vagus or medullary pathways by the end of the surgery. Results: All patients with permanent LAR loss (n = 5) or LAR-SC (n = 3), developed postoperative laryngeal dysfunction such as aspiration/pneumonia and permanent swallowing deficits (5.6%). Vocal-CoMEP findings refined postoperative vocal motor dysfunction. All seven patients with transient LAR-SC or loss, reverted by changing the surgical approach, did not present permanent deficits. Conclusions: Permanent LAR-SCs or loss correlated with postoperative laryngeal dysfunction and predicted motor and sensory dysfunction of the vagus nerve and reflexive medullary pathways. In contrast, a LAR-SC or loss, averted by a timely surgical adjustment, prevented irreversible damage. Significance: Monitoring of the LAR, with vocal-CoMEPs, may enhance safety to resect complex posterior fossa and brainstem lesions.