Value of distal compound muscle action potential duration prolongation in acute inflammatory demyelinating polyneuropathy: A European perspective

The value of distal compound muscle action potential duration (DCMAPD) has not been widely studied in acute inflammatory demyelinating polyneuropathy (AIDP) with electromyography (EMG) equipment at low‐cut filter settings <10 Hz, as used in Europe. Methods: We retrospectively reviewed the records of 40 patients with AIDP and 40 controls with axonal neuropathy, from Leicester, UK, and Angers, France. Results: The best combination of sensitivity/specificity for AIDP using DCMAPD prolongation in any one nerve was offered by cut‐offs from two other studies (sensitivity: 90% and 87.5%, respectively; specificity: 92.5% for both). Independent DCMAPD prolongation in any one nerve was better than, or equivalent to, other criteria. Conclusions: DCMAPD prolongation in any one nerve, at cut‐offs suggested by prior studies, represents a sensitive and specific marker to aid/simplify electrodiagnosis of AIDP in patients studied with EMG equipment with low‐cut filter settings of <10 Hz. Muscle Nerve, 2011