Scintillating scotoma
From Wikipedia, the free encyclopedia
| Scintillating scotoma | |
| Classification and external resources | |
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|---|---|
| Example of a scintillating scotoma, as may be caused by cortical spreading depression. | |
| ICD-10 | H53.1 |
| ICD-9 | 368.12 |
| eMedicine | neuro/480 |
| MeSH | D012607 |
Scintillating scotoma is the most common visual aura preceding migraine and was first described by 19th century physician Hubert Airy (1838–1903).
Contents |
[edit] Presentation
It may occur as an isolated symptom without headache in acephalgic migraine. Although many variations occur, scintillating scotoma usually begins as a spot of flickering light near or in the center of the visual fields, which prevents vision within the scotoma. The scotoma area flickers, but is not dark. The scotoma then expands into one or more shimmering arcs of white or colored flashing lights. An arc of light may gradually enlarge, become more obvious, and may take the form of a definite zig-zag pattern, sometimes called a fortification spectrum, because of its resemblance to the fortifications of a castle or fort seen from above.[1] The scotoma may be bilateral or unilateral and vision beyond the borders of the expanding scotoma(s) remain normal.
The visual anomaly results from abnormal functioning of portions of the occipital cortex, at the back of the brain, not in the eyes nor any component thereof, such as the retinas.[2] This is a different disease than retinal migraine that is monocular (only one eye).[3]
It may be difficult to read and dangerous to drive a vehicle while the scotoma is present. Normal central vision may return several minutes before the scotoma disappears from peripheral vision.
Sufferers can keep a diary of dates on which the episodes occur to show to their physician, plus a small sketch of the anomaly, which will vary between episodes.
[edit] Prognosis
Symptoms typically appear gradually over 5 to 20 minutes and generally last fewer than 60 minutes, leading to the headache in classic migraine with aura, or resolving without consequence in acephalgic migraine.[4]May also resolve without cephalgia.Many migraine sufferers evolve from scintillating scotoma as a prodrome to migraine; to scintillating scotoma without migraine. The scotoma spontaneously resolves within the stated time frame leaving little or no subsequent symptoms.
[edit] See also
[edit] External links
- AgingEye Times
- Imigraine.Net - includes images of scintillating scotomata
[edit] References
- Notes
- Gardner-Medwin AR (1981). "Possible roles of vertebrate neuroglia in potassium dynamics, spreading depression and migraine". J. Exp. Biol. 95: 111–27. PMID 7334315.
- Hadjikhani N, Sanchez Del Rio M, Wu O, et al. (2001). "Mechanisms of migraine aura revealed by functional MRI in human visual cortex". Proc. Natl. Acad. Sci. U.S.A. 98 (8): 4687–92. doi:. PMID 11287655.
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