Open AccessA‐waves increase the risk of developing neuropathy
Author(s) -
Srotova Iva,
Vlckova Eva,
Dusek Ladislav,
Bednarik Josef
Publication year - 2017
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.760
Subject(s) - abnormality , electromyography , medicine , nerve conduction , odds ratio , odds , nerve conduction velocity , f wave , physical medicine and rehabilitation , surgery , anatomy , logistic regression , psychiatry
A‐waves, which are observed following the M‐wave during motor nerve conduction studies ( NCS ), are late responses that are frequently found in many types of neurogenic disorders. However, A‐waves are also common in healthy individuals, where their significance remains unclear. The aim of this study was to examine whether the occurrence of A‐waves does in fact represent an increased risk for the future development of changes upon NCS or needle electromyography ( EMG ) in the corresponding nerve. Methods Nerve conduction studies/needle electromyography findings at control examination were evaluated in relation to the occurrence of initial A‐waves in 327 individuals who had undergone repeated NCS / EMG examination and exhibited normal initial findings, with or without the occurrence of A‐waves as the only acceptable abnormality. Results The odds ratio, which reflects the predictive power of the occurrence of A‐waves at the initial testing for the development of an abnormality (neuropathy or radiculopathy) at the follow‐up examination, ranged from 2.7 ( p = .041) in the tibial nerve and 3.9 ( p = .034) in peroneal one, to 30.0 ( p = .002) in the ulnar nerve. Conclusions A‐waves constitute an initial abnormality in all nerves, and they may be predictive for the future development of broader NCS / EMG abnormalities in the corresponding nerve.