Somatosensory evoked response evaluation of cervical spondylytic myelopathy

Abstract

There were 13 patients with cervical spondylytic myelopathy (CSM) evaluated. All had extradural defects with distortion of the cervical cord and partial or complete obstruction of myelographic dye. Posterior tibial scalp (SSEPs) were absent or delayed in all 13, whereas median SSEPs were abnormal in 9. Median SSEP abnormalties were limited to those with cord lesions at C5-C6 or above. There were eight patients with associated radiculopathies confirmed by electromyography. No meaningful differences in SSEPs were noted between those with or without root injury. Surgery confirmed the level of cord injury in 10. CSM is common with a high morbidity. The results indicate SSEPs using leg stimulation can be a sensitive indicator of cord injury in these patients and that the more commonly used arm stimulation is of value primarily for localizing the level of the myelopathy.

Evaluation of cervical spondylotic myelopathy using somatosensory-evoked potentials

“…There have been many reports regarding the utility of SSEPs in CSM patients. Several authors have reported tibial SSEPs to be the most sensitive test for CSM [10,16]; others claim that ulnar potentials are more sensitive than tibial SSEPs [15] or found no difference between the arm and the leg [4,7]. Although many studies have shown evoked potentials to be useful in detecting myelopathy in CSM, the prognostic value of these tests has so far rarely been examined in detail.…”

Superior sensitivity of motor over somatosensory evoked potentials in the diagnosis of cervical spondylotic myelopathy

“…Di found abnormal MEPs of the thenar in all of his patients with proven spondylotic myelopathy. Others reported that all patients with cervical spondylotic myelopathy had abnormal lower limb SEPs (Perlik and Fisher, 1987;Restuccia et al, 1992). In fact in these patients electrophysiological evaluation adds little to the diagnosis.…”

Intra-operative spinal cord monitoring in orthopaedics

“…However, some studies have shown that in patients with cervical myelopathy, median nerve SEPs show abnormalities only if there is cord compromise at the C5 ± C6 level or above, and less in patients in whom myelopathy extends to the C7 ± T1 level. 15 This ®nding indicates the need for monitoring of median and ulnar SEPs in cervical cord surgery. Spinal cord surgery involving levels below the eighth cervical segment requires monitoring of SEPs for stimulation of the posterior tibial nerve or common peroneal nerve.…”