Electrophysiological Classification of Guillain-Barre Syndrome: Sequential Changes in Electrophysiologic Findings

Shin, Jin Hong; Choi, Kwang Dong; Kim, Dae Seong; Jung, Dae Soo; Park, Kyu Hyun

Abstract

BACKGROUND: Guillain-Barre syndrome (GBS) is subclassified into acute inflammatory demyelinating polyneuropathy, acute motor or motor-sensory axonal neuropathy, and the other variants. While most studies from Western countries report demyelinating type as predominant form of GBS, some reports from Asian countries suggest the opposite result. Because they are not easily discriminated clinically, electrophysiological study is the most practical method for their subclassification.
METHODS
Among the patients who had been admitted to our hospital with typical clinical features of GBS over the past 4 years, we analyzed 32 patients, who had undergone at least 2 serial nerve conduction studies (NCS) throughout the course. In each case, conventional NCS in at least 3 limbs were performed and the criteria of Hadden et al., and 2 other criteria were applied.
RESULTS
Using the criteria of Hadden et al., 91% of the patients were classified as primary demyelination, and none as primary axonal pathology. Among the cases of primary demyelination, 21% showed electrophysiological features of axonal GBS at least in one occasion during the serial studies.
CONCLUSIONS
Our study suggests that the primary demyelinating type is by far more predominant in our population. Secondary changes of electrophysiological findings in some of our cases suggest that primary demyelination could be misinterpreted as primary axonal pathology without timely serial studies. For the epidemiologic study of larger scale in conjunction with clinical features and immunologic investigations, the protocol and criteria of consensus is necessary, with the qualified normal limit values of each laboratory.