Somatosensory Evoked Potentials (SSEP)

Somatosensory evoked potentials (SSEP) are recorded from the central nervous system following stimulation of peripheral nerves.

Introduction

Somatosensory Evoked Potentials (SSEPs) are electric signals recorded from the scalp or spine following stimulation to the peripheral nerves. They are time-locked responses, representing the function of the ascending sensory pathways. Early in the 1960s Larson et al introduced the use of somatosensory evoked potentials to monitor neural structure during neurosurgical procedures. It was utilized as a supplement to the wake-up test during correctional spinal surgeries for spinal deformities such as scoliosis to provide warning of compromised spinal cord function to the spine surgeons, as reported by McCallum et al and Nash et al in the 1970s. Since then SSEP has become one of the earliest and primary tools for intraoperative neurophysiological monitoring.

References

1. Larson SJ, Sances A. Evoked potentials in man: neurosurgical applications. Am J Surg 1966; 111: 857-861.
2. McCallum JE, Bennett MH. Electrophysiologic monitoring of spinal cord function during intraspinal surgery. Surg Forum 1975; 26: 469-471.
3. Nash CL, Long RA, Schatzinger LA, Brown RH. Spinal cord monitoring during operative treatment of the spine. Clin Orthop 1977; 126: 100-105.
4. Powers SK, Bolger CA, Edwards MSB. Spinal cord pathways mediating somatosensory evoked potentials. J Neurosurg 1982; 57: 472-82.
5. Simpson RK JR, Blackburn JG, Martin HF III, Katz S. Peripheral nerve fibers and spinal cord pathway contribution to the somatosensory evoked potentials. Exp Neurol 1981; 73: 700-15.
6. Toleikis JR. Intraoperative monitoring using somatosensory evoked potentials: A position statement by the American Society of Neurophysiological Monitoring. J Clin Monit Comput. 2005; 19(3):241-58.