ENTOPTIC PHENOMENA EXAMPLES SERIES

Although these are extremely difficult to demonstrate under experimental conditions ( 13, 14), the person affected can try to avoid subjective trigger factors. Possible trigger factors are often mentioned, such as increased physical activity/stress, sensory influences, or a disturbed day/night rhythm ( 12). No controlled trials have been conducted.

ENTOPTIC PHENOMENA EXAMPLES SERIES

Moreover, aspirin 80 mg proved highly effective in a case series of 49 patients with frequent (10.2×/month) migraine aura (reduction in 93%, including 20% with complete resolution) ( 11). In patients who experience auras very frequently and are bothered by them, preventive treatment with flunarizine or lamotrigine can be tried ( 10). To date, there is no reliably effective treatment. Migraine auras are usually self-limiting. Complex auras, e.g., successive visual and somatosensory auras, may last longer, but each individual modality should then last less than an hour. The blood oxygenation level-dependent (BOLD) signal migrated over the extrastriatal cortex at a rate of circa 3.5 mm/min, corresponding approximately to the speed calculated by Lashley in 1941 on the basis of observations of his own visual auras ( 9). Indirect confirmation of this concept was later provided by functional magnetic resonance imaging during spontaneous/triggered visual auras, showing changes in cerebral perfusion parallel to the diffusion of the visual aura in the field of vision ( 8). The neurophysiological correlate is cortical spreading depression (CSD), first described by Leão, in an animal experiment carried out in 1944, as a slow diffusion of stimuli over the cortex ( 7). Much rarer are visual auras in the form of altered object perception, with magnification or diminution (macropsia/micropsia) as in Alice in Wonderland syndrome (lifetime prevalence in patients with migraine: 15–19%) ( 5, 6). Although this form of visual aura is binocular, patients often do not realize it, frequently perceiving their vision as a 50/50 “screen” with the left half supplied by the left eye and the right half by the right eye. By the time the flickering has reached the periphery, it is usually no longer present centrally. Typical is the parallel or successive manifestation of irritative phenomena (“bright blinking lights”) and a visual field defect (“black hole”), as well as migration from central to peripheral. Characteristic of the typical visual aura is that it begins with development of a paracentral scotoma or of fortification figures (blinking diamond/kaleidoscope), followed by extension to the peripheral visual field. Overall, it is estimated that around 30% of migraine patients have auras, meaning that migraine auras can be assumed in about 3.5–8% of the population ( 1, 3, 4). “If I hold the affected eye closed, I see normally” Color desaturation and recovery during remission (e.g., optic neuritis).Persisting blindness, accompanied by, for example, “many dark dots ” (vitreous body hemorrhage preceding retinal detachment).Transient with slow development over 5–60 min (retinal migraine).Relative to absolute scotoma (archlike in migraine beamlike in retinal detachment).Inflammatory cause (e.g., optic neuritis).Malperfusion (e.g., central retinal artery occlusion ).→ NB: Discrepancy between patient’s description and lack of causative stimuli I see fields of roses in bloom at the top right, but I know they’re not really there” Visual perception of simple shapes to complex figures, persons, events “I can’t leave the house without sunglasses” “I see flashes of light that pop up just for a moment” Tracks: “A fast-moving ball has a tail”.After-images: “The picture on the screen goes with me.“After 30 minutes’ walking at night, I have to be led” Night blindness, in mild form disturbed night vision “Things appear larger or smaller than they are” “Street lights are surrounded by a ring of light”Īltered perception of objects, with increase or decrease in size

“Little threads move according to the direction I look in” “When I look up into the sky I see small wriggling dots”įloaters (mouches volantes/vitreous body opacities) Light-colored, erratically moving dots (leukocytes in the capillaries)

Blue field entoptic phenomenon (Scheerer phenomenon)

Entoptic phenomena examples