Atypical forms of Guillain-Barré syndrome and H1N1-influenza vaccination.

Recent epidemiological studies established extremely rare incidence of Guillain-Barre syndrome (GBS) after contemporary H1N1-influenza vaccine. We saw five patients with 'atypical' GBS variants that started within four weeks of 2010/2011 H1N1-influenza vaccine. There was no evidence for other etiologies of GBS. The patients presented with sensory ataxia, areflexia, extremity and oropharyngeal paresthesias, numbness, pain, weakness, sphincteric disturbances, and dysautonomia. One patient had Miller Fisher syndrome. All had elevated cerebrospinal fluid protein, and classic electrodiagnostic finding suggestive of GBS. All received the treatment with intravenous immunoglobulin with variable response. These pilot observations suggest that H1N1-influenza vaccine may be associated with rare and atypical variants of GBS. However, epidemiological studies with large cohorts are necessary to confirm excess cases of atypical GBS after H1N1-influenza vaccination.