Photosensitivity and Migraines
School holidays are upon us and many of you may have taken the kids along to see Incredibles 2. The movie has a warning for “photosensitive conditions’, migraine is one of these, today we discuss photosensitivity in this condition, as well as other sensory triggers in our blog.
Migraine is associated with altered processing of sensory stimuli.
Migraine attacks typically consist of intense, unilateral, throbbing headaches that are associated with sensitivities to light, sound, odours, and stimulation of the skin, as well as nausea and vomiting with or without accompanying auras.
Several studies have demonstrated that migraines differ in their processing and perception of sensory inputs. During the migraine attack, migraines develop an enhanced perception of painful and non-painful sensory, visual, auditory, and olfactory sensations. Between migraine attacks, atypical sensory perception persists, with migraines often demonstrating low discomfort thresholds to various experimentally applied stimuli.
Migraineurs have hypersensitivity to auditory still, altered perception of sound, an abnormal acuteness of hearing, activation of migraine attacks with auditory triggers and aversion of noise during migraine attacks. Approximately two=thirds of migraines report sensitivity to sound between migraine attacks. Migraineurs report that noise, such as traffic noise, can trigger migraine attacks. Sensitivity to sound increases during a migraine attack. Approximately 70-90% of migraine patients report sensitivity to or aversion to noise during a migraine attack.
Various odours, including pungent odours, perfumes, food smells, cigarette smoke and cleaning detergents, can be irritating to migraines. Migraineurs report sensitivity to odours during and between migraine attacks. Between attacks, migraines can detect the odour of vanillin, a pure olfactory nerve stimulant, at weaker concentrations compared with non-migraine healthy controls. About 50% of migraines report that odours can trigger their migraine attacks.
Migraineurs process and perceive visual information atypically. Most migraines report increased sensitivity to light between migraine attacks (75%) and light-induced aggravation of headache during a migraine attack (60-90%). As with auditory stimuli, migraine’s have reduced visual discomfort thresholds as compared to non-migraineur. Various visual stimuli can trigger a migraine attack, including exposure to sunlight, flashing or flickering lights, television, computer screens, and patterned lights.
Enhanced perceptions of sensory stimuli that are normally painful as well as those that are normally non harmful are displayed by Migraineurs. Approximately 60-70% of migraines develop cutaneous allodynia during the migraine attack. That is, they describe normally non harmful stimulation of the skin as painful. For allodynic migraineurs, shaving, showering, wearing earrings and classes and brushing hair can cause pain.
Migraineurs differ from non-migraineur in their processing of sensory stimuli. Increased sensitivity to sensory stimuli, lower discomfort thresholds to such stimuli, and migraine attack triggering via visual, auditory, and olfactory stimuli serve as evidence for atypical basal functioning of multiple regions in the migraine brain.
Future studies are needed to further define the mechanisms underlying atypical processing of sensory stimuli in migraineurs between and during migraine attacks.
Reference:
Curr pain Headache Rep. Harriott, Schwedt, 2014 Nov:18(11):458
Note: Information on this site is not a substitute for professional medical advice.
