THE DIAGNOSTIC UTILITY OF H-REFLEX LATENCY IN LUMBOSACRAL RADICULOPATHY
Sachin Pawar, Vinod Shende*, Ramji Singh, AR Chaudhari, Jayashree Pawar
ABSTRACT
Introduction: H-reflex is one of the types of late response in electrodiagnosis which allows evaluation of the functional state of the proximal portions of the peripheral nervous system, which are affected to a greater or lesser extent in the course of lumbosacral radiculopathy. Detection of structural abnormality in this disease by radiological imaging modalities is having high rate of false positivity and occasionally false negativity. Therefore, it is pertinent to study the effectiveness of H latency in diagnosis of lumbosacral radiculopathy. Objectives: The present study was undertaken to evaluate the diagnostic efficacy of H-minimum latency in lumbosacral radiculopathy. Methodology: In this cross- sectional study, a total of 283 subjects(168 males and 115 females) aged 40 years and above who were clinically diagnosed as having lumbosacral radiculopathy were enrolled after getting ethical approval and informed written consent. After doing detailed clinical and neurological examination, all the patients were subjected to electrophysiological evaluation using RMS EMG EP Mark –II machine in Clinical Neurophysiology unit, Department of Physiology through which their H-reflex study was conducted. Electrophysiological parameters studied was H-min latency in milliseconds (ms). Result: No statistically significant difference was observed between right and left sided values for the H-minimum latency tested in posterior tibial nerves (P >0.05). Accuracy of this electrophysiological parameter was observed to be 71.37% as compared to gold standard test and by using kappa statistics fair agreement was found between H-latency and MRI. Sensitivity and specificity of H-latency were found to be 66.67% and 90.91%. Conclusion: H-reflex studies are useful supportive diagnostic tool for lumbosacral radiculopathy.
Keywords: H-minimum latency, lumbosacral radiculopathy, nerve conduction study.
[Full Text Article]