Abstract: Bellís Palsy (BP) is a relatively common disease characterized by the sudden onset of unilateral facial paralysis. The facial muscle is paralyzed and patients cannot close the eyes control their saliva. Incidence ratio in world is between 11.5-40.2 patients per 100,000 of population. Factors that affect this disease are not clear. In a cross-sectional study in ARDABIL province and using a centralized system that contains demographic encounter data, the authors estimated rates, trends, and demographic risk of Bellís palsy during a 2-years period. There were 140 incident cases of Bellís palsy among patients referring to private clinic (total 6500 patients). The crude incidence rate was 2.15 . Incidence rates was high in age between 20-30 years and in females and was higher in cold season than warm ones and higher in cold statue and in farmer working in warm month (p< 0.05). The results are consistent with hypotheses regarding viral etiologies (e.g., reactivations of herpes simplex) of Bellís palsy that cold can activate this virus.
Dariush Savadi Oskoyi and Ali Abedi , 2008. Survey of Environmental Factors in Incidence of Bells Palsy in Ardabil . Research Journal of Biological Sciences, 3: 18-20.