Wolfram's syndrome is defined by the association of diabetes mellitus, diabetes insipidus, optic atrophy and nerve deafness. Other neurological anomalies, such as ataxia, nystagmus, tonic pupil, dizziness, dysarthria, dysphagia and epilepsy are rarely described and tend to appear later than the primary manifestations. We describe a patient with Wolfram's syndrome whose magnetic resonance image (MRI) of the head showed brainstem and cerebellar atrophy years before the appearance of clinical signs of brainstem disfunction. We conclude that alterations in MRI precede neurological symptoms by several years in Wolfram's syndrome.