Brainstem Auditory Evoked Potentials (BAEP) Flashcards

Which surgical procedure most commonly requires intraoperative BAEP monitoring?

Answer: Acoustic neuroma (vestibular schwannoma) resection

BAEP monitoring is most commonly used during acoustic neuroma resection to monitor auditory nerve and brainstem integrity during tumor removal.

Wave V of the BAEP originates from which neural structure?

Answer: Lateral lemniscus and inferior colliculus

Wave V is generated by the lateral lemniscus and inferior colliculus junction and is the most robust and clinically important BAEP component for intraoperative monitoring.

The standard acoustic stimulus used to elicit BAEPs intraoperatively is:

Answer: Broadband click stimulus

Broadband click stimuli are standard for BAEP elicitation because they activate a broad frequency range of cochlear hair cells simultaneously, producing reliable wave patterns.

An increase in Wave V latency of more than 1 ms from baseline during posterior fossa surgery is considered:

Answer: A significant alarm criterion

An increase in Wave V latency of 1 ms or more from baseline is a widely accepted alarm criterion during posterior fossa surgery, indicating auditory pathway compromise.

Which BAEP wave reflects activity at the level of the cochlear nerve (cranial nerve VIII)?

Answer: Wave I

Wave I of the BAEP is generated by the distal portion of cranial nerve VIII (cochlear nerve) near the cochlea and represents peripheral auditory nerve activity.

To prevent masking noise from the non-test ear from affecting BAEP recordings, what is applied to the contralateral ear?

Answer: Contralateral white noise masking

White noise masking is applied to the contralateral (non-stimulated) ear to prevent cross-hearing, where the stimulus is heard by the opposite ear and generates a second BAEP.