Peripheral nerve electrophysiology studies in relation to fatigue in patients with chronic inflammatory demyelinating polyneuropathy. Issue 12 (December 2020)

• Record Type: Journal Article
• Authors: Lawley, Andrew; Abbas, Ahmed; Seri, Stefano; Rajabally, Yusuf A.
• Is Part Of: Clinical neurophysiology. Volume 131:Issue 12(2020:Dec.)
• Page Start: 2926
• Page End: 2931
• Publication Date: 2020-12
• Subjects: Fatigue -- CIDP -- MUNIX -- Nerve conduction studies; Neurophysiology -- Periodicals; Electroencephalography -- Periodicals; Electromyography -- Periodicals; Neurology -- Periodicals; 612.8
• DOI: 10.1016/j.clinph.2020.08.011
• Languages: English
• ISSNs: 1388-2457

Abstract

Highlights: Experienced fatigue does not correlate with MUNIX or MUSIX sum scores in CIDP. Only CMAP area significantly correlated with experienced fatigue level on initial assessment. Change in fatigue level on repeat assessment did not correlate with changes in commonly used electrophysiology parameters. Abstract: Objective: To explore the relationship between fatigue, standard electrophysiological parameters and number and size of functioning motor units in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: Experienced fatigue was assessed using the linearly-weighted, modified Rasch-built fatigue severity scale (R-FSS) and the multidimensional Checklist of Individual Strength (CIS). Averaged electrophysiology values were calculated from multiple nerves. Motor Unit Number Index (MUNIX) technique was utilised to assess motor unit function. Assessments were repeated in 15 patients receiving regular intravenous immunoglobulin therapy, with changes in parameters calculated. Results: R-FSS and CIS scores did not correlate MUNIX or MUSIX sum scores from 3 different muscles. Inverse correlation was observed only between distal CMAP area and R-FSS but not CIS scores. However, changes in distal CMAP area and R-FSS scores on repeat assessment were not correlated. Conclusions: Experienced fatigue does not appear to correlate with loss of functioning motor units in patients with CIDP. Changes in experienced fatigue on repeat assessment did not correlate with changes in any of the electrophysiological parameters, suggesting fatigue experienced in CIDP is not strongly correlated with peripheral nerve dysfunction. Significance: Nerve conduction studies and MUNIX values do not appear to be useful surrogate markers for fatigue in CIDP.