What change in the BAER would be expected when cerebral blood supply to the brainstem is significantly reduced?

When cerebral blood supply to the brainstem is significantly reduced, one would expect to see an increased latency of wave V in the Brainstem Auditory Evoked Response (BAER). This is primarily due to the fact that ischemia or reduced blood flow impacts neuronal function, leading to a delay in the transmission of auditory signals through the auditory pathways, specifically within the brainstem.

Wave V originates from the lateral lemniscus and the inferior colliculus of the brainstem. Under conditions of reduced blood flow, neurons in these structures may become less responsive or take longer to activate, resulting in delayed signal transmission. The increased latency reflects a disruption in the normal processing of auditory signals due to the compromised physiological state of the neural tissue prompted by lack of adequate blood supply.

The impact of such ischemic conditions on the overall function of the auditory pathways is critical in neurophysiological monitoring, as it can indicate potential complications during intraoperative periods, such as decreased cerebral perfusion. Understanding the relationship between blood flow and auditory evoked potentials allows clinicians to better interpret BAER results during surgical procedures.