Figure 2.

The Basic laryngeal nerve anatomy/electrophysiology and standard monitoring equipment setup/procedures. (A) The basic equipment included the recording electrodes (RE) connected to the endotracheal tube (ETT) to place in contact with the bilateral vocal fold, the neural stimulating electrodes (SE) to stimulate the external branch of superior laryngeal nerve (SLN)(S), the Vagus nerve (VN)(V), and the recurrent laryngeal nerve (RLN)(R) during thyroid and parathyroid surgery. The standard procedure for performing IONM should include the laryngeal examination (L) before and after surgery(L1-L2), stimulating the SLN(S) before and after upper thyroid pole dissection (S1-S2), and stimulating the VN(V) and RLN(R) before and after the dissection. (B) Standard equipment setup (Recording (RE)/Stimulation (SE) side, ground (G) electrodes, interface connector box and monitor connections. The stimulating electrode (SE) can be used for mapping, localization, and identification of the SLN (S), VN (V), and RLN (R), and the evoked laryngeal EMG waveform can be viewed on the EMG monitor screen, and the amplitude and latency changes can be monitored during surgery.