Effect of conduction block in classification and prognosis of Guillain-Barre syndrome

<b>Aim:</b> The aim was to investigate the electro-physiological characteristics in disease progression of Guillain-Barre syndrome (GBS) and observe the effect of conduction block (CB) in classification and severity of the disease. <b>Methods:</b> Two hundred and ninety-four patients with GBS were divided into acute inflammatory demyelinating poly-neuropathy (AIDP) group, acute motor axonal neuropathy (AMAN) group and equivocal group according to their electro-physiological results and then reclassificated after electro-physiological review. All of the patients were followed for 6 months since their attacks. <b>Results:</b> Bad prognosis is more pronounced in AMAN group than in AIDP group (<i>P</i> &lt; 0.05). Most of the patients classificated as AIDP transformed into AMAN when CB occurred in the early phase of the disease. There is a positive relationship between CB in the early phase of the disease and severity of illness (<i>P</i> &lt; 0.05), but CB showed no correlation with prognosis of the patients (<i>P</i> &gt; 0.05). <b>Conclusion:</b> CB in the early phase of GBS indicates the probability of AIDP transforming into AMAN; it suggests that patients with CB in the early phase of the disease might be in serious conditions in a certain extent