6/5/2019 10:11:23 PM
Sensory conduction block in ulnar neuropathy at the elbow?
I've had a fair number of patients recently with primarily sensory signs and symptoms of ulnar neuropathy at the elbow but normal nerve conduction studies (ADM, FDI, antidromic D5, DUC) and EMG (typically just FDI). Occasionally I have included proximal sensory stimulation below and above the elbow (recording D5), but I have a hard time trusting the conduction velocities due to variable onset latencies.
My question for this community: While the studies above can exclude motor/sensory axon loss and motor conduction block, I don't know of a reliable way of assessing sensory conduction block at the elbow. Has anyone figured out how to do this? I realize that you can't rely on change in SNAP amplitudes because of physiologic temporal dispersion and phase cancellation, but perhaps with a side to side comparison or an index value?
Would appreciate any insight into this.