MRI in a patient with congenital agammaglobulinaemia.

MRI in a 17-year-old boy with known congenital agammaglobulinaemia (CA) demonstrated signs of chronic leptomeningeal inflammation with thickened, enhancing meninges. Furthermore, high signal was found symmetrically on T2-weighted images in the frontal and parietal white matter. The patient presented with severe general brain dysfunction and recent cerebellar ataxia. Extensive investigation did not reveal a causal agent. This case shows that MRI can be helpful in establishing the presence of pathological changes in cases where laboratory results are negative.