Is total duration of distal compound muscle action potential better than negative peak duration in the diagnosis of chronic inflammatory demyelinating polyneuropathy?
Copyright © 2013 Wiley Periodicals, Inc., a Wiley company
- Accepted manuscript online: 30 SEP 2013 12:40PM EST
- Manuscript Accepted: 10 SEP 2013
- Manuscript Revised: 3 SEP 2013
- Manuscript Received: 31 MAY 2013
- Cited By
- Distal CMAP duration;
- distal demyelination;
- diagnostic criteria
Introduction: The diagnosis of CIDP is difficult, and the role of electrophysiology is crucial. Distal CMAP duration is a useful tool that is assessed by measuring negative peak duration (NP). The value of total distal CMAP duration (T), which seems more precise from a physiological standpoint, has not been studied.
Methods: We reviewed retrospectively the records of 50 patients with CIDP and 50 controls with chronic axonal neuropathy. We constructed ROC curves for NP and T.
Results: Comparison of AUC for T versus NP showed an advantage for the former (P = 0.026 for the fibular nerve). Using our derived cut-offs offered a sensitivity of 42.3% for T versus 35.3% for NP.
Discussion: This study suggests a slight advantage for T over NP duration of the distal CMAP in the diagnosis of CIDP. However, the clinical relevance of this result must be weighed against the feasibility of this measurement. © 2013 Wiley Periodicals, Inc.