Somatosensory evoked potentials (SSEPs)

The SSEP is produced by stimulation of a peripheral nerve (arrow). The electrical activity enters via the dorsal nerve root and ascends the spinal cord via the dorsal column pathway, which mediates the senses of proprioception and vibration. It synapses at the cervicomedullary junction and crosses the midline ascending in the medial lemniscus to the ventral posterolateral nucleus of the thalamus, where it has a second synapse. From there it ascends to the sensory cerebral cortex. SSEP recordings can be made along the pathway; shown are responses from the peripheral nerve, spinal cord, cervical spine, and cerebral cortex.