Somatosensory Evoked Potentials (SSEP) Flashcards

What is the primary neural pathway monitored by upper extremity SSEP during intraoperative monitoring?

Answer: Dorsal column-medial lemniscal pathway

Upper extremity SSEPs monitor the dorsal column-medial lemniscal pathway, which carries proprioception and fine touch from the periphery to the cortex.

Which SSEP component is considered the most clinically significant cortical response when monitoring median nerve stimulation?

Answer: N20

The N20 is the primary cortical response generated in the contralateral primary somatosensory cortex and is the most clinically significant component for median nerve SSEP monitoring.

A 50% decrease in SSEP amplitude combined with a 10% increase in latency is generally considered:

Answer: A significant alarm criterion requiring intervention

A 50% amplitude decrease with a 10% latency increase meets the standard CNIM alarm criteria and requires immediate notification of the surgical team.

Which electrode placement is used to record the Erb's point potential during median nerve SSEP?

Answer: Ipsilateral to stimulation at the clavicle

Erb's point (N9) is recorded ipsilateral to the stimulation site over the brachial plexus at the clavicle, representing a peripheral nerve potential.

What does the P37 component represent in lower extremity SSEP monitoring via posterior tibial nerve stimulation?

Answer: Cortical response at the vertex

The P37 is a positive cortical potential recorded at the vertex (Cz) representing activation of the primary somatosensory cortex after posterior tibial nerve stimulation.

During SSEP monitoring, the N13 potential recorded at the cervical spine represents activity originating from:

Answer: The dorsal horn of the cervical spinal cord

The N13 is a stationary potential generated in the dorsal horn of the cervical spinal cord and serves as a subcortical reference point in SSEP monitoring.