Call-Fleming syndrome.

Call-Fleming syndrome is a part of reversible cerebral vasoconstriction syndrome (RCVS) group and is thought to be of idiopathic origin. It is classically described to be having multisegmental, focal vasospasms in the cerebral arteries. It is characterized clinically by the sudden onset of severe headache, classically described as thunderclap headache, with or without associated neurological deficits.