Migrainous infarction of the eye: Two cases of monocular ischemic complications associated with retinal migraine

Background Retinal migraine is defined by fully reversible monocular visual phenomena. We present two cases that were complicated by permanent monocular vision deficits. Cases A 57-year-old man with history of retinal migraine experienced persistent monocular vision loss after one stereotypical retinal migraine, progressing to finger-count vision over 4 days. He developed paracentral acute middle maculopathy that progressed to central retinal artery occlusion. A 27-year-old man with history of retinal migraine presented with persistent right eye superotemporal scotoma after a retinal migraine. Relative afferent pupillary defect and superotemporal visual field defect were noted, consistent with ischemic optic neuropathy. Conclusion Retinal migraine can complicate with permanent monocular visual loss, suggesting potential migrainous infarction of the retina or optic nerve. A thorough cerebrovascular evaluation must be completed, which was unrevealing in our cases. Acute and preventive migraine therapy may be considered in retinal migraine patients, to mitigate rare but potentially permanent visual loss.

Occipital ischaemic stroke after visual snow phenomenon – a case report

Background Persistent migraine with aura and neuroimaging examinations revealing ischaemia in the contralateral cortex may be associated with migrainous infarction. Despite being a neurological symptom that is distinct from migraine with aura, the visual snow phenomenon may also be associated with cerebral ischaemia. Here we describe a patient who reported short-lasting daily symptoms of visual snow that affected his entire visual field before becoming continuous and left-sided following acute occipital brain ischaemia. Case report In February 2017, a 74-year-old retired male was referred to our headache outpatient clinic with a diagnosis of recent right occipital cerebral ischaemia and migraine with aura. The patient reported visual snow symptoms that had changed from being bilateral and temporary to left-sided and permanent one day upon awakening; after being admitted to hospital a few hours later, he discovered he had had a stroke. He said he had never had any symptoms of migraine with aura. The visual snow phenomenon disappeared completely after about 1 year. Conclusions In our patient, a temporary daily visual snow phenomenon reversed to a persistent one. This phenomenon occurred in the part of his visual field that had been affected by the ischaemic occipital stroke, as typically happens in migrainous infarction. We hypothesise that the occipital lesion disrupted the inhibitory circuits, leading to a quadrantopic persistent visual snow. Since the mechanism may be the same as that observed in migrainous infarction, though with a different pathophysiology, it is possible to speculate that the aura in this case is the result, as opposed to the cause, of stroke in most patients.