Laser-evoked potentials: prognostic relevance of pain pathway defects in patients with acute radiculopathy

European Spine Journal

Michael Hauck²  Markus Quante¹  Jürgen Lorenz³ 

[1] Specialist Centre for Spinal Surgery, Hospital Neustadt, Am Kiebitzberg 10, 23730 Neustadt in Holstein, Germany;Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany;Department of Biomedical Engineering, Faculty of Life Sciences, Hamburg-University of Applied Sciences, Hamburg, Germany

关键词: Laser-evoked potential;    Sciatica;    Dorsal root impairment;    Prognosis;    Radiculopathy;   

DOI  :  10.1007/s00586-009-1169-4

学科分类：骨科学

来源: Springer

【 摘 要 】

The radicular pain syndrome is a major problem in public health care that can lead to chronic back and leg pain in 30%. Ischalgia and back pain are the most prominent signs of dorsal root affection. Until now, no clinical or neurophysiological test procedure exists that evaluates the function of the dorsal root and predicts the prognosis of patients suffering from RPS. We have recently demonstrated that laser-evoked potentials (LEP) are able to demonstrate dorsal root damage. With this study, we investigated 54 patients with acute radicular symptoms and compared LEP parameters (side to side difference of latency and amplitude, transformed to a z-score) with their state of health after 3 months to calculate their predictive value for outcome prognosis. Most significantly, the latency difference between the LEP of the affected dermatome relative to the contralateral healthy dermatome was able to predict the prognosis. Latency z score above two demonstrates a 91% specificity (33% sensitivity) for a poor outcome at 3 months. A significant relation between amplitude changes and the main outcome measure could not be shown. Only extreme changes (z score >10) in amplitude show a high specificity for the persistence of ischialgia in particular (specificity 0.94; sensitivity 0.35). All other parameters, such as clinical scores or other LEP parameters, were not able to predict the outcome of patients. We propose that clinical testing using LEP with latency analysis is a useful tool for estimating the course of disease, so that patients with poor predictive parameters can be treated more invasively at early disease stages to avoid persistence of radiculopathy.

【 授权许可】

Unknown