During thyroidectomy, stimulation of the vagus produces no laryngeal response before dissection begins, but direct stimulation of the recurrent laryngeal nerve produces a response. What is the most likely issue?
A distal nerve response demonstrates an intact laryngeal neuromuscular pathway. Failure only with vagal stimulation points to access, current delivery or anatomy at the proximal stimulation site rather than inevitable RLN injury.
A. Definite recurrent laryngeal nerve transection: The recurrent nerve responds directly.
B. Bilateral vocal-fold fixation: A direct evoked response argues against complete fixed obstruction as the explanation.
C. Superior laryngeal nerve palsy: This does not selectively abolish vagal monitoring while preserving RLN stimulation.
D. Hypocalcaemia: Calcium level does not create this site-specific monitoring discrepancy.
E. A technical problem proximal to the recurrent nerve, such as vagal electrode contact or stimulation setup: A distal nerve response demonstrates an intact laryngeal neuromuscular pathway. Failure only with vagal stimulation points to access, current delivery or anatomy at the proximal stimulation site rather than inevitable RLN injury.
If both vagal and direct recurrent-nerve responses were lost after dissection despite corrected equipment and no blockade, neural injury would be more likely.
Independent Clinora educational preparation material; not official JCIE content, an accredited programme, clinical advice, or a substitute for current guidance, local policy and specialist judgement.
Back to the Section 1 bank