Migraine and the environment.
Migraineurs often describe environmental triggers of their headaches, such as barometric pressure change, bright sunlight, flickering lights, air quality, and odors. Environmental aspects of indoor space and workplaces are also implicated in migraine experience. Comprehensive migraine treatment programs emphasize awareness and avoidance of trigger factors as part of the therapeutic regimen. As migraine has a substantial economic impact, remediation of correctable environmental triggers may benefit employee attendance and productivity among migraineurs. Few controlled studies in the literature, however, confirm environmental influences on migraine and headaches. Although some are controversial, migraineurs worldwide consistently report similar environmental triggers. This article addresses commonly mentioned environmental triggers with a discussion of their pathophysiology and proposed preventive measures.


OBJECTIVE
To examine the epidemiological evidence for commonly-mentioned environmental migraine triggers, discuss their possible role in the pathophysiology of migraine and propose preventive measures to avoid or minimize exposure.


BACKGROUND
Migraineurs often describe environmental triggers of their headaches, such as barometric pressure change, bright sunlight, flickering lights, air quality and odors. Environmental aspects of indoor space and workplaces are also implicated in the migraine experience. As migraine has a substantial economic impact, remediation of correctable environmental triggers may improve attendance and productivity among migraineurs in the workplace.


METHODS
We reviewed the literature addressing indoor and outdoor environmental factors which are commonly implicated as migraine triggers.


RESULTS
Although some factors are controversial, migraineurs worldwide consistently report similar environmental triggers. However, few studies confirm environmental influences on migraine and headaches. Research to date indicates that migraineurs have lower thresholds for light-induced discomfort, sine grating distortion and illusions, noise tolerance and olfactory sensitivity compared to the general population.


CONCLUSIONS
There are conflicting studies supporting the validity of patient-reported environmental migraine triggers. Prospective studies are needed to determine the extent that external stimuli influence the migraine process. Decreased thresholds for light, noise, olfactory and visual stimuli in migraineurs may be minimized by modifying the work, home and classroom settings.
Friedman
Deborah I
DI
Department of Ophthalmology and Neurology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
De ver Dye
Timothy
T
D000397:Air Pollution / Q000009:adverse effects; D000399:Air Pressure; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D008027:Light / Q000009:adverse effects; D008881:Migraine Disorders / Q000453:epidemiology / Q000209:etiology*; D009622:Noise / Q000009:adverse effects; D009812:Odorants; D020795:Photophobia / Q000150:complications / Q000453:epidemiology; D012307:Risk Factors; D012684:Sensory Thresholds; D014887:Weather