MRI and evoked potentials in a child with hydranencephaly.

Magnetic resonance imaging and evoked potential studies were performed on an infant with hydranencephaly. Magnetic resonance imaging demonstrated the absence of cortical tissue with a structurally intact mid- and hind-brain. Evoked potentials confirmed the loss of cortical activity with preservation of brainstem function. These diagnostic tests gave efficient and precise information concerning the extent of the intracranial pathology and prognosis.