Diagnostic Usefulness of Dermatomal Somatosensory Evoked Potentials by Low Intensity Stimulation in Lumbar Radiculopathy.

, Seo, Jeong Hwan; , Kim, Ji Yeon; , Ko, Myoung Hwan; , Eun, Jong Pil

Original Article

Journal of the Korean Academy of Rehabilitation Medicine 2007;31(3):341-345.

Seo, Jeong Hwan , Kim, Ji Yeon , Ko, Myoung Hwan , Eun, Jong Pil

¹Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine, Chonbuk National University Medical School, Korea. happijy@hanmail.net
²Department of Neurosurgery, Chonbuk National University Medical School, Korea.

요수 신경근병증에서 저강도 자극 피부절 체성감각유발전위의 유용성

서정환, 김지연, 고명환, 은종필¹

전북대학교 의과대학 재활의학교실 및 임상의학 연구소, ¹신경외과학교실

Abstract

Objective
To investigate diagnostic usefulness of dermatomal somatosensory evoked potentials (DSEP) in the evaluation of lumbar radiculopathy using stimulation intensity lower than conventional stimulation intensity.
Method
Fifty-seven patients with low back pain were studied with DSEP and needle electromyography (EMG). The radiculopathy was diagnosed by lumbar MRI or operative findings. The DSEP study was performed with stimulation intensity of 1.0×, 1.5×, 2.5× sensory threshold, respectively. We compared the sensitivity and specificity of DSEP and needle EMG in the evaluation of L5 radiculopathy.
Results
Radiological and operative findings revealed unilateral herniated disc and L5 root compression in 38 patients (66.7%). Nineteen patients had no significant L5 root compression. The sensitivity and specificity of abnormality were 68.4% and 78.9% in 1.0× sensory threshold stimulation; 71.1%, 78.9% in 1.5× sensory threshold stimulation; and 44.7%, 84.2% in 2.5× sensory threshold stimulation, respectively. Whereas they were 55.2% and 100% in needle EMG.
Conclusion
DSEP using low stimulus intensity showed higher sensitivity in the diagnosis of L5 radilculopathy, and DSEP might provide additional diagnostic usefulness in the evaluation of patients with suspected L5 radiculopathy. (J Korean Acad Rehab Med 2007; 31: 341-345)

Key Words: Dermatomal somatosensory evoked potentials, Lumbar radiculopathy, Stimulation intensity, Needle electromyography