Nerve Excitability Changes in Chronic Inflammatory Demyelinating Polyneuropathy: A New Clinical Diagnostic Biomarker

Publication date: April 2014 Source:Journal of Experimental & Clinical Medicine, Volume 6, Issue 2 Author(s): Jowy Tani , Chin-I Chen , Jia-Ying Sung The diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) mainly relies on clinical presentation and traditional nerve conduction studies. However, diagnosing CIDP with an atypical presentation remains a challenge. Availability of an additional diagnostic utility, such as the nerve excitability test (NET), can improve clinicians' ability to diagnose CIDP. In this article, we present a review of published papers on the changes in nerve excitability parameters in CIDP. Among the nerve excitability parameters, a baseline increase of the threshold current in a stimulus–response curve, decreased strength–duration time constant, and “fanning-out” pattern of the threshold electrotonus are consistently noted. The recovery cycle might show increased superexcitability and the current–voltage relationship might show inward rectification, but these changes are less consistently noted. These parameters are compatible with membrane hyperpolarization in CIDP. On longitudinal follow-up, normalization of nerve excitability parameters is noted after intravenous immunoglobulin treatment. We also report a case of acute-onset focal CIDP with a longitudinal nerve excitability study, where nerve excitability changes consistent with previous studies have enabled early diagnosis. NET may be a useful tool for clin...
Source: Journal of Experimental and Clinical Medicine - Category: Journals (General) Source Type: research