Retinal Migraine - The Basics Updated
One of the difficulties encountered at times when discussing migraine occurs when a migraineur is given a diagnosis that isn't actually accurate or "official" in diagnostic terms, but is really a descriptive term. Such terms may be used fairly frequently, but they fall short of a diagnosis and may also be used differently from one doctor to another. That's one reason why most doctors diagnose based in the International Headache Society's International Classification of Headache Disorders, 3rd Edition (ICHD-3). A "standard" diagnosis also makes communications and transitions easier when patients need to consult other doctors or change doctors.
There are several terms that are sometimes used, supposedly as migraine diagnoses, that involve visual symptoms. Most of them aren't actually standard migraine diagnoses. Retinal migraine, however, is an actual migraine diagnosis. What becomes confusing about it is that it's sometimes misused, resulting in a misdiagnosis. The term "retinal migraine" is often misused to mean any migraine that involves any visual symptoms or a migraine with visual symptoms but without the headache phase of the attack.
ICHD-3 Criteria for 1.2.4 Retinal Migraine:
Repeated attacks of monocular visual disturbance, including scintillations, scotomata or blindness, associated with migraine headache.
- At least two attacks fulfilling criteria B and C
- Aura consisting of fully reversible monocular (in one eye) positive and/or negative visual phenomena (e.g. scintillations, scotomata or blindness) confirmed during an attack by either or both of the following:
1. clinical visual field examination
2. the patient’s drawing (made after clear instruction) of a monocular field defect
- At least two of the following three characteristics
1. the aura spreads gradually over 5 minutes or longer
2. aura symptoms last 5-60 minutes
3. the aura is accompanied, or followed within 60 minutes, by headache
- Not better accounted for by another ICHD-3 diagnosis, and other causes of amaurosis fugax have been excluded.
Some patients who complain of monocular visual disturbance in fact have hemianopia. Some cases without headache have been reported, but migraine cannot be ascertained as the underlying aetiology.
1.2.4 Retinal migraine is an extremely rare cause of transient monocular visual loss. Cases of permanent monocular visual loss associated with migraine have been described. Appropriate investigations are required to exclude other causes of transient monocular blindness.
As noted above, the headache phase of a retinal migraine begins during or within 60 minutes of the visual symptoms. The headache phase presents symptoms consistent with migraine without aura.
The relevant diagnostic criteria for migraine without aura are:
- Headache attacks lasting 4–72 hours (untreated or unsuccessfully treated)
- Headache has at least two of the following characteristics:
1. unilateral location
2. pulsating quality
3. moderate or severe pain intensity
4. aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs)
- During headache at least one of the following:
1. nausea and/or vomiting
2. photophobia and phonophobia
The primary differentiating factors between retinal migraine and migraine with aura are:
- The visual symptoms of retinal migraine are monocular.
- Total, but temporary, monocular blindness may occur in retinal migraine.
Retinal Migraine Treatment:
For infrequent attacks, medications used for other forms of migraine are often employed to relieve the other symptoms. These medications can include NSAIDs, antinausea medications, Midrin equivalents, ergotamines the triptans. The choice of medications is somewhat affected by the age of the patient. When migraines are frequent, the same preventive therapies used for other migraines can be explored.
More Helpful Articles in Our "Basics" Series:
Migraine with Brainstem Aura – The Basics (formerly called basilar-type migraine)
Headache Classification Committee of the International Headache Society. “The International Classification of Headache Disorders, 3rd edition.” Cephalalgia. July 2013 vol. 33 no. 9 629-808. 10.1177/0333102413485658.