| Identifier |
Positive_visual_phenomenon_Part_I_Entoptic_Migraine_Occipital_Seizures |
| Title |
Positive Visual Phenomena I: Entopic, Migraine Occipital Seizures |
| Creator |
Andrew G. Lee, MD; Peter Wojcik |
| Affiliation |
(AGL) Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, Texas; Professor of Ophthalmology, Weill Cornell Medicine, New York City, New York; (PW) Class of 2020, Baylor College of Medicine, Houston, Texas |
| Subject |
Pathology; Signs and Symptoms; Migraines; Seizures |
| Description |
Dr. Lee lectures medical students on positive visual phenomena. |
| Transcript |
So we are going to be covering positive visual phenomenon. Positive is different from negative. Positive the patient sees something. Negative they don't see anything. So positive visual phenomenon the patient will say I see something. A flashing light, a jagged line, something like that. And when patients complain about positive visual phenomena it's good to ask them to draw it. We like to know if its one eye or two eyes. Bilateral or unilateral. In general, if its unilateral its in the eye and if its bilateral its in your brain. The most common unilateral visual positive phenomena that we have is called entoptic phenomena. Ent mean in and optic means eye and the most common causes of entoptic phenomena are vitreous traction, posterior vitreous detachment, retinal detachment. So patients with retinal detachments or posterior detachments or floaters might say I see a flashing light. So the retina cannot make a formed visual image, so it either makes flashing lights or nothing, that's pretty much what it can do. So unilateral we've been thinking about entoptic phenomenon, flashing lights. If its bilateral we'd like to know the character of the phenomenon and migraine is a super common bilateral simultaneous and often hemianoptic positive visual phenomenon. The key differentiating features is the geometric nature of the phenomenon which we call a fortification scotoma because it looked like an old fort would look like in the old days and it typically starts small and gets bigger and moves across the visual field. And that we call march and buildup. There might be colors in it and the colors might be flashing off and on and that's what we call a scintillation scotoma. So a bilateral, geometric, fortification, scintillating, colored or flashing scotoma that starts small and gets bigger lasts about 20 minutes and the headache follows that's going to be compatible with migraine. In contrast, occipital seizure is usually not this jagged line It usually lasts seconds at a time and its geometric, small, little circles. So small colored circles seconds at a time, bilateral, simultaneous, that is almost always occipital in origin and occipital seizures is what we're going to be worried about. Lasts seconds at a time they might have mental status changes or generalized. So if you just knew these three main categories, entoptic phenomenon, migraine aura or an occipital seizure, that's most of the positive phenomena that we see. And you got to differentiate it from photopisas which is just, "I see a flashing light" which is almost always a retinal sign. So positive visual phenomenon mostly migraine. |
| Date |
2019-03 |
| Language |
eng |
| Format |
video/mp4 |
| Type |
Image/MovingImage |
| Collection |
Neuro-Ophthalmology Virtual Education Library: Andrew G. Lee Collection: https://novel.utah.edu/Lee/ |
| Publisher |
North American Neuro-Ophthalmology Society |
| Holding Institution |
Spencer S. Eccles Health Sciences Library, University of Utah |
| Rights Management |
Copyright 2019. For further information regarding the rights to this collection, please visit: https://NOVEL.utah.edu/about/copyright |
| ARK |
ark:/87278/s66h8wdq |
| Setname |
ehsl_novel_lee |
| ID |
1403734 |
| Reference URL |
https://collections.lib.utah.edu/ark:/87278/s66h8wdq |
