Seasonal variation in the clinical recovery of patients with Guillain Barré syndrome requiring mechanical ventilation.

BACKGROUND: Guillain Barré Syndrome (GBS) has a variable clinical course. The influence of season on the rate of recovery has not been evaluated previously, despite documentation of seasonal variation in the occurrence of GBS. This study evaluated the influence of season on the rate of recovery from GBS.

MATERIALS AND METHODS: Records of 184 patients with GBS over a 10-year period were reviewed. Patients were divided into four groups depending on the date of admission: Q1 (March-May), Q2 (June-August), Q3 (September-November), and Q4 (December-February). Demographic characteristics and recovery characteristics (duration of mechanical ventilation, ICU and hospital stay, and time for recovery from the time of initiation of definitive therapy) were compared across the four quarters.

RESULTS: There was no significant difference in age, antecedent illnesses, treatment received, electrophysiological findings, and muscle power at admission across the four groups. Significant differences among various seasons were found with respect to duration of mechanical ventilation (23 ± 20, 36 ± 34, 27 ± 22, and 38 ± 28 days for Q1-Q4, respectively; P = 0.05), ICU stay (27 ± 22, 40 ± 37, 31 ± 23, and 43 ± 30 days for Q1-Q4, respectively; P = 0.05), hospital stay (42 ± 28, 55 ± 44, 47 ± 34, and 72 ± 54 days for Q1-Q4, respectively; P = 0.02), and time for recovery from treatment (15 ± 14, 29 ± 34, 18 ± 14, and 29 ± 20 days for Q1-Q4, respectively; P = 0.02).

CONCLUSIONS: This study demonstrates a seasonal variation in the recovery of patients with GBS requiring mechanical ventilation. Patients admitted in Q1 have the fastest recovery and those in Q4 have the slowest recovery.