AANEM Connect

Dear colleagues,

I am seeking clarification on an observation that frequently appears in my daily electrodiagnostic practice: patients with lumbosacral radiculopathies seem to demonstrate EMG evidence of denervation more often than those with cervical radiculopathies.

Clinically, this pattern appears consistent, yet I have not found a clear statement in the literature directly addressing whether lumbosacral radiculopathies are objectively more likely to show needle EMG abnormalities than cervical ones.

While reviewing available studies, I did find data suggesting a difference in detection rates. For example:

• Hassan et al. (Can J Neurol Sci, 2013) reported EMG-confirmed radiculopathy in 62% of lumbosacral cases vs 31% of cervical cases in their cohort.

• Lefkowitz, “Electrodiagnosis of Radiculopathies” (AAPMR/NOW review) summarizes typical sensitivity ranges as approximately 49–86% for lumbosacral radiculopathy and 50–72% for cervical when paraspinal muscles are included.

• Several reviews (e.g., Narayanaswami et al., 2016) note factors that may reduce the likelihood of detecting cervical denervation, including overlapping myotomal innervation, variable motor involvement in cervical root compression, and technical challenges in paraspinal sampling.

These trends seem to align with what many of us observe in practice, but I have not found a paper that explicitly states this comparison as a distinct conclusion.

My question:
Is there a definitive study, review, or consensus source that directly addresses whether lumbosacral radiculopathies produce denervation changes detectable by EMG more frequently than cervical radiculopathies? If so, I would appreciate references or guidance toward the most authoritative literature on this topic.

Thank you in advance for your insights.