Proceedings of the 25th BCTRIMS Annual Meeting

Case Presentation

A 17-year-old male patient presented with 12 months of progressive painless loss of vision in the right eye. After 2 years from the first symptom, he presented to our service with finger count in and a central scotoma in left eye, worsening in the last 2 weeks. He had a previous diagnosis of Autism with important restricted eating.  MRI from neuroaxis showed atrophy of the optic nerves, with a high-intensity signal in the left nerve on the T2-weighted imaging, with no other lesion. He has a bilateral pale disc, with no retinal involvement. MOG and AQP4-IgG (CBA) were negative. A trial of high-dose intravenous methylprednisolone as attempted, with no improvement. Most important hypotheses were nutritional and hereditary neuropathy, with inconclusive tests: four mitochondrial mutations were tested with no positive results, however the FGF-21, was high.  Complex B vitamins were: B12 148, folic acid 5,4 and vitamin A 0,2. Both nutritional replacement and antioxidant therapy were implemented.

Discussion

Leber hereditary optic neuropathy (LHON) is an inherited mitochondrial disease that leads to decreased vision in both eyes. The loss of vision usually consists in bilateral central scotoma, but the entire visual field can be lost.  Nutritional optic neuropathy, especially complex B and vitamin A, also presents a painless bilateral progressive visual loss, with a central scotoma, and time dependent treatment response. Unfortunately, in this case, the time it took from the first symptom to first assistance may have inflicted poorer prognosis.

Final Comments

The differential diagnosis for optic neuropathies is challenging, especially in a public service with limited tools available. Besides demyelinating diseases, infections and systemic auto-immune diseases, genetic and nutritional etiologies should always be reminded.