P.001 Transient neurapraxic radiculopathy

Abstract

Background: Neurapraxia is considered to be a temporary disorder of peripheral nerve conduction due to trauma that does not cause axonopathy. However, patients with radiculopathy, confirmed by MRI, who may not have active axonal damage with evidence of spontaneous activity may still report transient give-way weaknesss. In the absence of active changes on intramuscular recording a neurophysiologic consultation may fail to substantiate any significant neurologic concern. This report documents and objectifies prone positioning-induced radicular neurapraxic weakness in an elderly man. Methods: An 83-year-old gentleman was referred for neuromuscular evaluation with regards to peripheral neuropathy. He had a history of low back pain and MRI evidence of multilevel DDD and discogenic neuroforaminal narrowing. Strength testing was performed by Biodex evaluation. Routine electrophysiologic assessments were performed. Results: On neurologic examination proximal strength iwas normal with grade 4 dorsiflexion strength. Stocking-glove loss to pinprick was absent. Preliminary objective testing of the right quadriceps revealed a peak torque of 87.1 Nm. Immediately after lying prone for 3 minutes (for paraspinal EMG), his power dropped to 33.7 Nm. Strength fully recovered by 36 hrs. Conclusions: This case documents evidence of a 61% reversible reduction in torque in the right quadriceps after prone lying. Electromyographers need to be cautious with radiculopathy patients during paraspinal testing.