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Título

Atypical migraine with transient binocular blindness: case report

RESUMO

Case presentation
A 58 year-old male with systemic arterial hypertension, rheumatoid arthritis and HIV started, 3 years ago, episodes of acute bilateral blindness lasting about 20 minutes, 5 episodes a year, without other symptoms. He also had a previous history of intense pulsating headache, which started 20 years ago, with nauseas, photo and phonophobia, about 3 times a week, independent of the blindness episodes. His neurological examination showed no alterations. Brain MRI, intracranial and cervical CT angiography, 24h holter and transthoracic echocardiogram were within the normal limits. He was started on treatment with valproic acid 250 mg bid, which was suspended due to trunk urticaria. Amitriptyline 50 mg daily was started, with a reduction in intensity and frequency of both headache and blindness episodes. The diagnosis was of migraine with binocular blindness aura.
Discussion
Visual aura is the most frequent type of migraine associated aura, which mechanism is cortical spreading depression in the occipital cortex. However, complete vision loss in both eyes associated with migraine is extremely rare. Recent publications described binocular blindness as migraine aura and its main hypothesis was retinal spreading depression. Studies with chick retinas showed that retinal spreading depression occurs similarly to cortex. Furthermore, migraine with binocular blindness does not appear to be a subform of basilar-type migraine as the blindness occurs in isolation without other symptoms required for ICHD-3 basilar type migraine diagnosis, and retinal migraine is characterized by monocular blindness. A recent case report described two unrelated families with repetitive transient daily blindness in five members that had clinical characteristics of a retinal electrical signal abnormal propagation that may be a retinal spreading depression. One study with many migraine patients showed low incidence of binocular blindness. They were all female, had some abnormality of clotting factors and no history of previous aura. Their episodes were infrequent and may even occur only once in life. The authors suggest classifying episodes of transient blindness as an aura-like event of acute onset. Our patient had no other cause to explain his symptoms. Both episodes of bilateral blindness and headache improved with amitriptyline, contributing to the diagnosis.

Palavras Chave

migraine, binocular blindness