Transient global amnesia after cerebral angiography with iohexol.

We describe a patient without a previous history of migraine or epilepsy and with no known vascular risk factors, who suffered subarachnoid haemorrhage. During vertebral angiography using nonionic contrast medium (iohexol), spasm of the basilar artery was seen. The patient suffered transient global amnesia. Angiography 3 months later with the same contrast medium was normal and produced no further deficit. This case lends support to the supposed ischaemic aetiology of transient global amnesia; in patients without other evidence of cerebrovascular disease, arterial spasm may be responsible.