Clusters of Bell's palsy

Abstract

The idiopathic facial paralysis or Bell's palsy installs abruptly or within a few hours, without any apparent cause. It corresponds to approximately 75% of all peripheral facial palsies. Three theories try to explain its pathogenecity: vascular-ischemic, viral and auto-immune. We reviewed the records of the EMG Sector, Hospital do Servidor Público Estadual (São Paulo, Brazil), from 1985 to 1995 and found 239 cases of Bell's palsy. Data were analysed according to age, gender, seasonal distribution of cases. There was a predominance of cases in the 31-60 age bracket (40.59%). The female gender was responsible to 70.71% of cases. There was a predominance of cases in winter (31.38%) and autumn (30.13%), which was statistically significant. These findings let us to suppose that Bell's palsy predominates in females, in 41-60 years age bracket, and occurs predominantly in cold months. There are groups of clusters throughout temporal distribution of cases and cases are dependent on one each other or on factors affecting them all, which reinforces the infectious hypothesis (there is a rise in the incidence of viral upper respiratory tract infection during cold months).

Fisioterapia na paralisia facial periférica: estudo retrospectivo

“…In about 50% of the population affected by peripheral facial paralysis, the etiology is unknown. The first and foremost incidence is agnogenic, or Bell's palsy, the second is trauma, among others 2,5 . High blood pressure, diabetes mellitus, viruses, pregnancy and breastfeeding are deemed associated conditions 2,3,6,7 .…”

Aetiology of Acquired Lower Motor Neuron Type of Facial Nerve Paralysis– A Descriptive Study

“…The female gender accounted for 70.71% of cases in the study by Gonçalves-Coêlho TD et al 6 Laura Sánchez-Chapul et al 7 had 63.7% (160) women and 36.3% (91) men in their study.…”

Effects of Wind Chill Factor, Temperature and Other Meteorological Parameters on the Incidence of Bell's Palsy: Results Based on a Retrospective, 7-Year Long, Greek Population Study

“…Supposedly, combination of certain, yet not fully elucidated, ideal climatic conditions may facilitate HSV-1 primary infection or render human tissues more vulnerable to HSV-1 reactivation [11]. First of all, there is a well-established correlation between cold, winter seasons and the observed number of cases [10,11,12,13,14]. An obvious explanation should attribute the effect in the existence of an inverse association between the risk for BP and the absolute values of temperature [2,15].…”