• MRI
• NEUROOPHTHALMOLOGY
• NEUROTOXICOLOGY
• STROKE

A 19-year-old woman was referred with poor vision in each eye. Two years previously, while living in Bangladesh, she had woken up feeling very unwell and confused. She vomited several times and her parents took her to a local emergency department. While there she could not see well in either eye and this progressed throughout the day. MR scan of the brain and orbits with contrast showed acute bilateral putaminal infarcts but no white matter lesions; the anterior visual pathway appeared normal and did not enhance with contrast. An extensive stroke work-up was normal, including CT angiogram from aortic arch to the vertex, Holter ECG monitoring and transthoracic echocardiogram. Serum neuromyelitis optica antibody titres were normal. She was presumed to have bilateral optic neuritis and treated with intravenous methylprednisolone (1 g daily for 3 days), followed by a long oral prednisone taper. Her vision subsequently improved only slightly.

On current examination, her visual acuity was 6/60 in each eye and there was no relative pupillary defect. Funduscopy showed that both optic nerve heads were diffusely pale. Humphrey visual fields (24-2 algorithm) showed dense caecocentral scotomas in each eye (figure 1A). Optical coherence tomography of the peripapillary retinal fibre layer showed symmetrical thinning predominantly involving axons of the papillomacular bundle (figure 1B). MR scan of the brain (T2-weighted) showed bilateral putaminal hyperintensities and smaller calibre of both optic nerves, but no pathological enhancement or white matter brain lesions (figure 1C).