Reversible cerebral vasoconstriction syndrome 3 months after blood transfusion.

Reversible cerebral vasoconstriction syndrome is characterized by the prolonged but reversible constriction of cerebral arteries accompanied by a sudden onset of severe headache, and is sometimes complicated by subarachnoid hemorrhage or cerebral infarction. It is associated with various clinical conditions and treatments, although the precise pathophysiology is not understood. In particular, several cases of this syndrome have been described to occur in middle-aged women within 1 week of a blood transfusion.