Vitamin A deficiency mimicking CNS demyelination

Abstract

Introduction: Severe vitamin A deficiency causing significant visual impairment is rarely encountered in children. We present a case of optic neuropathy associated with Vitamin A deficiency mimicking central nervous system (CNS) demyelination. Case: A three year old girl with a background of cow’s milk protein intolerance presents with a gradual history of painless visual loss over three weeks. This only became noticeable to her family when she was unable to see close objects. An urgent ophthalmology opinion was sought, which demonstrated evidence of bilateral optic neuropathy. MR imaging of her brain and spine demonstrated multiple areas of subtle high signal changes including the cervical cord and splenium of the corpus callosum. Although imaging was suggestive of demyelination, her ophthalmology findings were more indicative of a long-standing neuropathy. Steroid therapy was therefore held off pending further investigations, which confirmed an undetectable Vitamin A level. This was treated with Vitamin A supplementation, which has resulted in stability of her vision and visual fields. Discussion: Nutritional optic neuropathies are uncommon but need to be thought of in high risk patients. On further review of our patient’s history, she was found to be a very picky eater with limited intake of products rich in Vitamin A. CNS demyelination is not a reported feature of Vitamin A deficiency and the subtle imaging changes seen in our case are likely to be coincidental. Early diagnosis and treatment of Vitamin A deficiency is crucial in preserving vision and preventing further visual deterioration. Conclusion: In children who present with gradual visual loss and optic neuropathy, consideration should be given to nutritional deficiencies such as Vitamin A deficiency. The presence of subtle changes on imaging suggestive of demyelination may sometimes be a red herring and clinical correlation is needed to clinch the correct diagnosis.