A treatable cause of ataxia in children.

An 11-year-old black male presenting with severe subacute sensory ataxia, unusual skin hyperpigmentation, megaloblastic anemia, low serum B12 levels, and an abnormal part I Schilling test was diagnosed with pernicious anemia in the context of a polyglandular syndrome. Intrinsic factor and thyroid microsomal antibodies were positive, and thyroid-stimulating hormone levels were undetectable. There was a strong familial aggregation because the mother, a maternal aunt, the maternal grandfather, and the maternal great-grandmother had been diagnosed with pernicious anemia, albeit of unspecified etiology. Spinal magnetic resonance imaging (MRI) demonstrated extensive demyelination of the posterior columns along the entire length of the cord, as well as areas of contrast enhancement. Treatment with cobalamin produced complete remission of the neurologic deficits and normalization of the MRI findings in the short space of 2 months. Although rare, childhood pernicious anemia is a treatable disease that should be included in the differential diagnosis of the sensory ataxias in children. In this article, we review the causes of pernicious anemia in children and discuss the MRI findings.