Guillain-Barré syndrome in Greece: seasonality and other clinico-epidemiological features

The epidemiologic and clinical features of Guillain-Barré syndrome (GBS) during a 13-year period in a region of south-western Greece with an average population of 819 009 inhabitants are described. Clinical records of all patients between 1 January 1989 and 31 December 2001 who were admitted in the two referring hospitals of the above district and fulfilled the criteria for idiopathic GBS were reviewed. Overall 105 patients were identified. The age adjusted to European population incidence rate per 100 000 person-years was 1.02 (95% CI: 0.84-1.24) and a male preponderance was found. The highest number of cases (35; 33.3%) occurred in spring and the lowest (17; 16.2%) in autumn, although this tendency did not reach a significant level. Cases with and without preceding illness were similarly distributed in the seasons. Electrophysiologic abnormalities of axonal type were found in 6.1% of patients. The mortality rate was 2.8% and the long-term outcome 5%. The incidence of GBS was relatively low and the prognosis was close to the best reported. Spring clustering has also been observed in other countries with mild climate.