How is the median nerve SSEP-N18 potential typically recorded?

The median nerve SSEP (Somatosensory Evoked Potential) N18 potential is typically recorded referentially from scalp electrodes that are ipsilateral to the stimulated nerve. This method allows for the detection of the N18 potential, which reflects the cortical processing of sensory information from the median nerve. The SSEP waveform consists of various peaks, and N18 is identified as one of the early peaks indicating an electrical response in the somatosensory cortex in response to peripheral nerve stimulation.

Using ipsilateral electrodes enables a more direct recording of the neural activity associated with the stimulus. This is important as it maximizes the signal-to-noise ratio, enhancing the clarity of the evoked response. Such placement ensures that the recorded activity is primarily from the area of interest, promoting accurate interpretation and monitoring during surgical procedures involving the upper extremities or the brain.

In contrast, the other options involve different methodological approaches or placements, which are not standard for recording the median nerve SSEP N18 potential. For example, bipolar derivations and cervical spine electrode placements do not align with the typical referential approach used in this context, leading to less effective monitoring of the cortical response. Using an off-site reference does not provide the localized measurement needed for the specific