Generality
The scintillating scotoma is a visual manifestation very often associated with migraine with aura.
This symptom consists in the perception of a dark speck surrounded by small colored stripes with intermittent brightness, in a visual hemifield. In practice, the subject experiencing a scintillating scotoma sees an "area of lesser visual efficiency, while the details present in the rest of the visual field are perceived normally.
The scintillating scotoma occurs for reasons not yet fully known, but, in most cases, this symptom can be favored by the narrowing of the blood vessels associated with the eyes. This (usually transient) vasoconstriction reduces the sensitivity of the retina, hence the efficiency of vision.
What's this
The scintillating scotoma consists in the perception of luminous traces that circumscribe a dark spot in a visual hemifield. This sort of patch surrounded by flashes or colored stripes corresponds to an "area of reduced or absent sensitivity of the retina, which manifests itself as an" altered response to the light stimulus.
Regardless of the observed object, this spot does not undergo displacements in relation to the rest of the visual field.
The scintillating scotoma has a rather variable frequency, while the duration of the manifestation is correlated to the pathological event. This symptom can manifest itself in the visual field of one or both eyes.
Causes
The scintillating scotoma is a visual manifestation that is found more frequently in migraine with aura, in the context of which it represents a prodromal symptom.
There are, however, other situations in which they can arise. For example, scintillating scotomas can occur in relation to vision problems and various diseases related to the functionality of the eye, including:
- Glaucoma;
- Detachment of the retina;
- Opacity of the lens (cataract);
- Pathologies of the macula;
- Alterations of the optic nerve (eg neuritis) and / or localized lesions at the level of the optic pathways (from the retina to the visual cortical centers).
In other cases, scintillating scotomas may be secondary to:
- Poisoning;
- Vascular problems (eg circulatory spasms of the retinal artery or ocular haemorrhages);
- Ischemia, injury or brain tumors.
More rarely, scintillate scotoma is due to the undesirable effect of certain medications.
Symptoms and complications
The scintillating scotoma is a manifestation that consists in the appearance in the visual field of a dark spot, from which broken lines or wavy stripes of various colors (yellow, red, blue and green) develop. The flashing area can also have the appearance of a flashing circle or curl.
These manifestations, in most of the occasions, occur together with many other very annoying symptoms. For example, the patient may also suffer from headaches, overall fatigue, dizziness, nausea, and vomiting.
This particular type of scotoma is characteristic of migraine with aura and frequently precedes the actual attack. In this case, this prodromal symptom is temporary and lasts a few minutes (usually no more than half an hour), before disappearing to give way to the typical intense headache.
Diagnosis
Upon examination of the visual field, the scintillating scotoma is graphically represented as a dark area circumscribed by a spot with intermittent brightness and variable color, which is projected on the fixed objects and can have various localizations (peripheral or central).
