Electrical impedance myography in the diagnosis of radiculopathy

Muscle Nerve. 2013 Nov;48(5):800-5. doi: 10.1002/mus.23833. Epub 2013 Sep 11.


Introduction: We sought to determine whether electrical impedance myography (EIM) could serve as a diagnostic procedure for evaluation of radiculopathy.

Methods: Twenty-seven patients with clinically and radiologically diagnosed cervical or lumbosacral radiculopathy who met a "gold standard" definition underwent EIM and standard needle electromyography (EMG) of multiple upper or lower extremity muscles.

Results: EIM reactance values revealed consistent reductions in the radiculopathy-affected myotomal muscles as compared with those on the unaffected side; the degree of asymmetry was associated strongly with the degree of EMG abnormality (P < 0.001). EIM had a sensitivity of 64.5% and a specificity of 77.0%; in comparison, EMG had a sensitivity of 79.7% but a specificity of 69.7%.

Conclusions: These findings support the potential for EIM to serve as a new non-invasive tool to assist in diagnosis of radiculopathy; however, further refinement of the technique is needed for this specific application.

Keywords: cervical radiculopathy; electrical impedance; electromyography; lumbosacral radiculopathy; muscle; reactance.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Cervical Vertebrae / innervation
  • Electric Impedance
  • Electromyography / instrumentation
  • Electromyography / methods
  • Electromyography / standards*
  • Female
  • Humans
  • Lower Extremity / innervation
  • Lower Extremity / physiopathology*
  • Lumbosacral Region / innervation
  • Male
  • Middle Aged
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / physiopathology*
  • Needles / statistics & numerical data
  • Radiculopathy / diagnosis*
  • Sensitivity and Specificity
  • Severity of Illness Index