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Abstract Details

Use of the Laringeal Adductor Reflex monitoring technique in Posterior Fossa Surgery.

The laryngeal adductor reflex (LAR) monitoring technique, elicited by electrical stimulation of the vocal fold mucosa with endotracheal tube surface based electrodes, has been proved to be a reliable and robust method for intraoperative monitoring of the integrity of the Vagus nerve in thyroid and cervical spine surgery. It is based on the recording of the contralateral R1(cR1) and R2(cR2) motor responses using the endotracheal tube electrode contralateral to the stimulating electrode. Its utility however is still to be validated for posterior fossa surgery, especially when lower cranial nerves, such as the Vagus, are at risk of injury such as in oncological surgery near the cerebello-pontine angle.

We are presenting a case series of 4 patients who underwent cerebello-pontine angle surgery using the aforementioned technique along with a multimodal setting for intraoperative monitoring (IOM) including free run EMG and corticobulbar MEPs for cranial nerves. In all of our patients, the LAR was 100% reliably elicited and could predict changes even before the appearance of alterations in the other more traditional modalities of IOM. No peri-operative complications or adverse outcomes were observed.

We therefore conclude that the LAR is a reliable method to monitor the entire vagus nerve reflex arc and shows a promising utility in posterior fossa surgery.

TitleForenamesSurnameInstitutionLead AuthorPresenter
DrAnaMirallave PescadorQueen´s Hospital
DrNizarMuhammedQueen's Hospital
DrJacquieDeebQueen's Hospital
MrAlirezaShoakazemiQueen's Hospital
MrJonathanPollockQueen's Hospital
Sinclair F, Tellez MJ (2017) 'A novel methodology for assessing laryngeal and vagus nerve integrity in patients under general anesthesia': Clin Neurophysiol, 128(7), pp. 1399-1405.
Sinclair CF, Tellez MJ (2017) 'Contralateral R1 and R2 components of the laryngeal adductor reflex in humans under general anesthesia': Clin Neurophysiol, 127(12), pp.E443-E448.
Yamashita T, Nash EA (1997) 'Effects of stimulus intensity on laryngeal long latency responses in awake humans': Otolaryngol Head Neck Surg, 117, pp. 521–529.
Bhabu P, Poletto C (2003) 'Thyroarytenoid muscle responses to air pressure stimulation of the laryngeal mucosa in humans': Ann Otol Rhinol Laryngol 112:834–840.
Carey B, Sulica L (2013). 'A novel means of clinical assessment of laryngeal nerve conduction': Muscle Nerve 47, pp. 432–436.