What is the frequency setting for CN VII CMAP?

The frequency setting for the facial nerve (CN VII) compound muscle action potential (CMAP) is typically set between 1 kHz and 1.5 kHz. This range is chosen to optimize the recording of the CMAP, which reflects the electrical activity produced by muscle fibers following stimulation of the facial nerve.

The lower frequency settings may not adequately capture the necessary muscle response, as they can limit the ability to detect rapid changes in CMAP amplitude or latency, which are critical in intraoperative monitoring. Conversely, frequencies higher than 1.5 kHz may filter out important components of the CMAP signal. By using a setting in the range of 1-1.5 kHz, practitioners ensure they capture the most relevant data while minimizing noise and artifacts that could interfere with interpretation. This frequency range effectively balances sensitivity and specificity in monitoring facial nerve function during surgical procedures.