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

Abstract

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. We retrospectively reviewed the records of 40 patients with AIDP and 40 controls with axonal neuropathy, from Leicester, UK, and Angers, France. 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. 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.