Effects of environmental and weather conditions on myasthenia gravis - in search of the missing link

Abstract

Ambient temperature can modulate neurotransmission in the peripheral nervous system. Transmission at the neuromuscular junction is also influenced by ambient temperature. Myasthenia Gravis (MG) is an autoimmune disease of the neuromuscular junction characterized by impaired transmission of the nerve impulses to the muscle fibers. The aim of the study was to determine if there is in fact a statistically significant correlation between environmental fluctuations and MG exacerbations among myasthenic patients. Also, the authors intended to find candidate variables for validation in a future prospective study. The subjects included in the study were hospitalized in I Neurology Clinic of Prof. Dr. N. Oblu Emergency Clinical Hospital Iasi, Romania during a five years period. The authors performed a binary logistic regression on 195 hospital admissions from which 144 were from Iasi County. P values<0.05 were considered significant. The risk of myasthenic aggravation appeared to be higher when the extremes of temperature from the week before hospitalization were greater with a p < 0.001 and Exp(B) of 1.143 (95%CI: 1.1 -1.187). This statistically significant correlation maintained when a subgroup analysis of 144 admissions from Iasi county was performed. Also, apparently females had a greater risk of exacerbation when ambient temperature fluctuations were higher. These are promising remarks that represent a hypothesis for a prospective study. In addition, further studies are mandatory in order to establish a link between myasthenic aggravations and other environmental parameters such as atmospheric pressure and humidity.