RESUMO
The diagnostic evaluation of chronic low back pain (CLBP) is difficult, as its primary causes are multiple. Clinical, radiological and electrophysiological findings are of limited value in diagnosing radiculopathy as the cause of CLBP in early cases. Current study was undertaken on 50 controls and 50 CLBP patients without clinical neurological deficit to evaluate the potential of nerve conduction studies, particularly H-reflex study for diagnosis of radiculopathy in these cases. We observed that routine nerve conductions in CLBP without clinical neurodeficit showed no significant differences; whereas all the H-reflex parameters, H-threshold, H latency, H amplitude and H/M ratio were significantly different when compared with that of control (P value <0.0001 in each case). We concluded that subclinical cases might not have only partial conduction block but also secondary axonal loss due to compression of nerve roots. We further suggest inclusion of Soleus H-reflex study in evaluation of radiculopathy among early CLBP cases without clinical neurodeficit.