[Adrenoleukodystrophy. Diagnosis of a typical case using magnetic resonance].

A case of a two and a half year old boy with unexplained repeated episodes of hyponatremic dehydration and hyperkalemia, as well as noticeable psychomotor retardation and hyperpigmentation is presented. His neurologic development was considered normal until he was two, when he progressively began to regress. Magnetic resonance imaging of the brain showed white matter demyelination and cortical atrophy as well as primary adrenal insufficiency when stimulated with ACTH. Both magnetic resonance imaging and the ACTH stimulation test are useful for the diagnosis of adrenoleukodystrophy. Adrenoleukodystrophy; hyponatremic dehydration; cutaneous hyperpigmentation; white matter degenerative disease; magnetic resonance imaging.