Clinical localization · Core
Build a case for radiculopathy
Cervical & lumbosacral radiculopathy
A myotomal pattern across peripheral nerves supports root localization.
01SNAPs and preganglionic disease
- Typical root lesions are proximal to the dorsal root ganglion, so distal SNAPs are often preserved.
- Ganglion location, coexisting neuropathy and other exceptions prevent this rule from being diagnostic alone.
02Needle strategy
- Seek consistent abnormalities in the same myotome across different peripheral nerves, with appropriate paraspinal sampling.
- Myotomes overlap. Document uncertainty when multiroot disease or pain limits localization.
03Positive and negative findings
- Purely sensory or non-motor-axonal root disease can have a normal needle examination.
- Isolated paraspinal abnormalities require consideration of age, prior surgery and nonspecific changes.
Related nerves
Pause and explain
Explain in your own words: “EDX assesses physiological injury; imaging assesses structure. Both need clinical correlation.” Then think of a situation in which it could be misinterpreted.
Show a review prompt
Normal EMG does not exclude every radicular pain syndrome, and one abnormal muscle cannot precisely identify a root.
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References and further reading
- Electrodiagnosis of Radiculopathies ↗AAPM&R KnowledgeNow · Society educational review · Link accessed 2026-09-08
Educational synthesis; independent neuromuscular specialist review is pending. Publication dates and compilation dates are distinct. This is an original teaching synthesis; consult the source for complete methods and criteria.