TY - JOUR
T1 - Nerve excitability changes in chronic inflammatory demyelinating polyneuropathy
T2 - A new clinical diagnostic biomarker
AU - Tani, Jowy
AU - Chen, Chin I.
AU - Sung, Jia Ying
N1 - Funding Information:
This review was supported by Taipei Medical University—Wan Fang Medical Center Research grant no. 101-wf-eva-10 .
PY - 2014/4
Y1 - 2014/4
N2 - 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 clinical neurophysiologists for early diagnosis and follow-up of CIDP.
AB - 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 clinical neurophysiologists for early diagnosis and follow-up of CIDP.
KW - Chronic inflammatory demyelinating polyneuropathy
KW - Clinical predictor
KW - Immunotherapy
KW - Nerve excitability
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U2 - 10.1016/j.jecm.2014.02.011
DO - 10.1016/j.jecm.2014.02.011
M3 - Review article
AN - SCOPUS:84898007213
SN - 1878-3317
VL - 6
SP - 43
EP - 49
JO - Journal of Experimental and Clinical Medicine(Taiwan)
JF - Journal of Experimental and Clinical Medicine(Taiwan)
IS - 2
ER -