Transient Binocular Vision Loss

What is it?

Migraine
- Flickering zigzag (“fortification scotoma”) migrates across the visual hemifield of both eyes for 20 to 30 minutes
- Visual aura often switches sides in successive attacks
- Accompanying features
  - Headache may follow visual symptoms or be absent (“acephalgic migraine,” “migraine equivalent”)
  - Hemibody weakness and/or numbness or language difficulty may uncommonly occur, following each other (never concurrently!)
- First migraine attack usually occurs within the first three decades of life, but…
- Trap: the first migraine attack may occur after age 50 (“late-life migraine”)
- Tip: migraine differs from transient ischemic attack and seizure (see next tabs) in this way: 1) the scintillation travels across the hemifield and disappears after 20- 30 minutes; 2) other symptoms--including especially headache, hemibody numbness, and language difficulty—do not occur at the same time as the visual symptoms, but rather follow them because the aura of migraine is based on a migrating cortical depolarization
Vertebrobasilar transient ischemic attack
- Stationary blank spots or flickering lights (but no zigzags) lasting less than 2 minutes
- Diplopia, dizziness, dysphagia, dysesthesias may occur owing to brainstem/diencephalic ischemia

Occipital lobe seizure
- Stationary and sometimes colored flickers of variable duration
- Head and eye deviation to one side sometimes
- Tonic-clonic movements sometimes
- Loss of consciousness (with secondary generalization of the seizure)
- Structural abnormality is usually evident in the occipital lobe on brain imaging
Systemic hypertension
- No distinctive accompanying features except headache
- Tip: transient vision loss episodes may be monocular or binocular and of variable duration
Systemic hypotension
- Vision dims or disappears for seconds to hours upon standing or sitting up and sometimes spontaneously
- History of vigorously treated hypertension, dehydration, lightheadedness (presyncope) or fainting (syncope)
Papilledema
- Vision dims or disappears for less than 30 seconds upon standing or sitting up and sometimes spontaneously (“transient obscurations of vision”)
- Tip: transient vision loss episodes may be monocular, occurring in the eye where the papilledema is relatively severe

Patient report of “black outs” may mean loss of consciousness rather than loss of vision

Elicit clinical features of migraine
Unless the diagnosis of migraine is secure, further emergent evaluation is needed, as follows
- Ophthalmoscopy to rule out papilledema
- Blood pressure to rule out hypertension or hypotension
- Erythrocyte sedimentation rate and C-reactive protein (for low likelihood of giant cell arteritis)
- Complete blood count, protein electrophoresis (for hypercoagulable state)
- Non-contrast head CT (for brain bleed, other large mass, hydrocephalus)
The following tests can be performed non-emergently
- Echocardiogram (for heart wall or valvular disease)
- Heart rhythm monitoring (for atrial fibrillation)
- MRI and MRA (for occipital mass lesions, recent stroke, and vasculopathy)

Migraine
- Preventive treatment is usually not necessary
- Cessation of smoking reduces risk of stroke
Vertebrobasilar transient ischemic attack
- Diagnosis of atrial fibrillation is critical to reduce stroke risk
- Standard stroke risk reduction measures must be instituted
Occipital lobe seizure
- Brain MRI usually shows a pertinent structural abnormality
- Electroencephalography may show interictal abnormalities
Systemic hypertension
- Blood pressure must be controlled, but not rapidly or excessively
Systemic hypotension
- Anti-hypertensive medication regimen may need modification
- Cardiac output must be optimized
- Hydration may be helpful
Papilledema
- Cause of elevated intracranial pressure must be sought