Acute headache as a presenting symptom of tacrolimus encephalopathy.

A 24 year old woman presented with a sudden excruciating headache mimicking an acute vascular event. She had undergone a lung transplantation because of cystic fibrosis and was receiving maintenance treatment with tacrolimus and prednisone. Ancillary investigation excluded vascular causes. Magnetic resonance imaging demonstrated hyperintense lesions in the infratentorial and parieto-occipital regions consistent with posterior leucencephalopathy syndrome. Both her clinical condition improved and the lesions disappeared completely after withdrawal of tacrolimus, suggesting that her condition could be explained by a tacrolimus encephalopathy.