Evoked Response Monitoring

In neurocritical care, clinical examination is often inconclusive and the information obtained from imaging is insufficient to arrive at an accurate diagnosis or predict prognosis. Monitoring the evoked responses in such situations might add functional information to aid decision-making. Sensory stimulation and tracing the impulses to cortex provide valuable information about the intactness of the pathway tested. By intercepting the pathway at various levels, the location of pathology can be identified. Brain stem auditory and visual evoked responses are used routinely in the operating theatre and neuro ophthalmology, respectively, but their utility is limited in critical care. Somatosensory evoked potential testing is used in critical care routinely for neuroprognostication after cardiac arrest. This chapter discusses the relevant neuroanatomy, technical details of testing, recording, interpretation, indications, and limitations of somatosensory evoked responses in critical care.