We present the case of a 12-year-old boy who developed progressive limbic dysfunction associated with a posterior cord syndrome in conjunction with complex partial seizures and intrathecal synthesis of IgG. Although the cerebral CT scan appeared normal, MR imaging showed signal abnormalities in both temporal lobes. As these clinical features reminded us of the well-known paraneoplastic encephalomyelitis (PNEM) in adults, we looked for a tumour and found a pelvic neuroblastoma. The diagnosis of PNEM was supported by the discovery of the antibody anti-HU in the serum of our patient.