摘要
Objective: To determine the diagnostic value of motor evoked potentials (MEPs ) in the diagnosis of lumbosacral cord disorders. Methods: MEPs in 37 patients with sensory and motor deficits in the lower limbs were studied. MRI demonstrated spinal cord involvement in 10 patients and cauda equina lesions in 27 patients. A double determination of cent ral motor conduction time (CMCT), calculated as the difference between the laten cies of responses evoked by cortical and paravertebral magnetic stimulation and as the difference between the latency of cortical MEP and the total peripheral c onduction time calculated from the F-wave latency, enabled discrimination betw een a delay along the proximal root and a delay along the corticospinal tract. A n abnormality of the CMCT calculated with both techniques is indicative of centr al motor pathway damage, whereas an abnormality of the CMCT calculated from the latency of responses evoked by paravertebral magnetic stimulation associated wit h a normal CMCT calculated from the F-wave latency suggests a cauda equina les ion. Results: Neurophysiologic findings strongly correlated with the lesion site documented by MRI (cauda equina or lumbosacral cord). All patients with MR evid ence of cord involvement had an abnormality of CMCT calculated with both methods , suggesting a lesion of central motor pathways. Clinical examination often fail ed to document a spinal cord lesion, suggesting pure peripheral involvement in 5 of the 10 patients with MR evidence of cord lesion. Conclusion: Motor evoked po tential recording is an accurate and easily applicable test for the diagnosis of lumbosacral spinal cord lesions.
Objective: To determine the diagnostic value of motor evoked potentials (MEPs ) in the diagnosis of lumbosacral cord disorders. Methods: MEPs in 37 patients with sensory and motor deficits in the lower limbs were studied. MRI demonstrated spinal cord involvement in 10 patients and cauda equina lesions in 27 patients. A double determination of cent ral motor conduction time (CMCT), calculated as the difference between the laten cies of responses evoked by cortical and paravertebral magnetic stimulation and as the difference between the latency of cortical MEP and the total peripheral c onduction time calculated from the F-wave latency, enabled discrimination betw een a delay along the proximal root and a delay along the corticospinal tract. A n abnormality of the CMCT calculated with both techniques is indicative of centr al motor pathway damage, whereas an abnormality of the CMCT calculated from the latency of responses evoked by paravertebral magnetic stimulation associated wit h a normal CMCT calculated from the F-wave latency suggests a cauda equina les ion. Results: Neurophysiologic findings strongly correlated with the lesion site documented by MRI (cauda equina or lumbosacral cord). All patients with MR evid ence of cord involvement had an abnormality of CMCT calculated with both methods , suggesting a lesion of central motor pathways. Clinical examination often fail ed to document a spinal cord lesion, suggesting pure peripheral involvement in 5 of the 10 patients with MR evidence of cord lesion. Conclusion: Motor evoked po tential recording is an accurate and easily applicable test for the diagnosis of lumbosacral spinal cord lesions.
出处
《世界核心医学期刊文摘（神经病学分册）》
2005年第5期37-38,共2页
Digest of the World Core Medical Journals:Clinical Neurology
