Contemporaneous Evaluation of Intraoperative Ulnar and Median Nerve Somatosensory Evoked Potentials for Patient Positioning: A Review of Four Cases.

Somatosensory evoked potentials (SSEPs) are a valuable tool for assessing changes in peripheral nerve pathways caused by patient positioning during spinal surgeries. These changes, when left undiagnosed, may lead to postoperative neurological sequelae. Why an upper extremity SSEP attenuates due to positioning is not necessarily clear and can be multifactorial, affecting the peripheral nerves or elements of the brachial plexus.