A neurological complication of inferior petrosal sinus sampling during investigation for Cushing's disease: a case report.

A 45 year old woman with hirsutism was found to have classic biochemical features of ACTH dependent Cushing''s disease, with partial cortisol suppression in response to dexamethasone. As no pituitary adenoma could be visualised by CT or MRI, she proceeded to bilateral simultaneous inferior petrosal sinus sampling before possible surgery. During the course of this procedure she had a stroke affecting the brainstem at the level of the pontocerebellar junction. This complication of petrosal sinus sampling has been previously described but is not widely recognised; the procedure should only be undertaken when results of less invasive tests are equivocal.