Diagnostic signs of motor neuropathy in MR neurography: nerve lesions and muscle denervation

Daniel Schwarz, Markus Weiler, Mirko Pham, Sabine Heiland, Martin Bendszus, Philipp Bäumer
European Radiology 2015, 25 (5): 1497-503

OBJECTIVE: To investigate the diagnostic contribution of T2-w nerve lesions and of muscle denervation in peripheral motor neuropathies by magnetic resonance neurography (MRN).

METHODS: Fifty-one patients with peripheral motor neuropathies underwent high-resolution MRN by large coverage axial T2-w sequences of the upper arm, elbow, and forearm. Images were evaluated by two blinded readers for T2-w signal alterations of median, ulnar, and radial nerves, and for denervation in respective target muscle groups.

RESULTS: All 51 patients displayed nerve lesions in at least one of three nerves, and 43 out of 51 patients showed denervation in at least one target muscle group of these nerves. In 21 out of 51 patients, the number of affected nerves matched the number of affected target muscle groups. In the remaining 30 patients, T2-w lesions were encountered more frequently than target muscle group denervation. In 153 nerve-muscle pairs, 72 showed denervation, but only one had increased muscle signal without a lesion in the corresponding nerve.

CONCLUSIONS: MRN-based diagnosis of peripheral motor neuropathies is more likely by visualization of peripheral nerve lesions than by denervation in corresponding target muscles. Increased muscular T2-w signal without concomitant nerve lesions should raise suspicion of an etiology other than peripheral neuropathy.

KEY POINTS: • In peripheral neuropathy, T2-w nerve lesions are more frequent than muscle denervation. • Muscle denervation almost never occurs without detectable lesions in corresponding nerves. • MRN-aided diagnosis of peripheral motor neuropathy should focus primarily on nerve lesions. • Increased muscular T2-w signal intensity without concomitant nerve lesions indicates other aetiology.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"