Checkpoint: Basic NCS and Anomalous Innervations-Test Your Knowledge: Application Cases

Test Your Knowledge: Application Cases

Pdf Summary

The 2025 presentation focuses on electrodiagnostic case studies and testing to understand nerve lesion pathophysiology in clinical scenarios. It includes practice cases and real cases analyzing motor and sensory nerve conduction parameters—latency, amplitude, and conduction velocity—and their interpretation to differentiate conditions such as demyelination, conduction block, axon loss, or mixed pathologies.<br /><br />Practice cases provided radial, peroneal, median, and ulnar nerve conduction data at multiple stimulation points to identify lesion types by comparing latency delays, amplitude reduction, and slowed conduction velocity. For example, radial nerve testing showed progressive latency delays and amplitude drops suggestive of particular nerve injury types, with similar approaches used for peroneal and median nerves.<br /><br />Clinical cases illustrated diagnostic approaches:<br />- Case 1: A 36-year-old female with foot drop post-injury showed conduction block possibly at the fibular head with uncertain axon loss needing EMG confirmation. Ultrasound demonstrated nerve swelling.<br />- Case 2: A 37-year-old male with bilateral hand numbness likely had early carpal tunnel syndrome, exhibiting demyelination as the first electrodiagnostic abnormality.<br />- Case 3: A 55-year-old male with neck pain and right arm symptoms had normal nerve conduction studies consistent with radiculopathy. Electrodiagnostic findings suggested Martin-Gruber anastomosis affecting interpretation.<br />- Case 4: A 73-year-old woman with bilateral burning feet demonstrated findings consistent with a likely axonal polyneuropathy based on absent sural responses and slowed tibial conduction velocities.<br /><br />The session underlined the importance of detailed electrodiagnostic testing and interpretation, use of EMG for mixed or unclear cases, and evaluation of conduction blocks versus axon degeneration. Practical application includes identifying lesion site and type to guide diagnosis and treatment in peripheral nerve disorders.<br /><br />Audience engagement incorporated interactive quizzes via the Slido app and encouraged feedback through the AANEM app, with instructions on claiming continuing medical education credits.

Keywords

electrodiagnostic case studies

nerve lesion pathophysiology

motor nerve conduction

sensory nerve conduction

latency amplitude conduction velocity

demyelination diagnosis

conduction block

axon loss

peripheral nerve disorders

electromyography (EMG)