Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by the 
association of severe headaches with or without additional neurological symptoms 
and a 'string and beads' appearance on cerebral arteries, which resolves 
spontaneously in 1-3 months. We present the clinical, neuroimaging and outcome 
data of 67 consecutive patients prospectively diagnosed over 3 years in our 
institution with an angiographically confirmed RCVS. There were 43 females and 
24 males with a mean age of 42 years (19-70). RCVS was spontaneous in 37% of 
patients and secondary in the 63% others, to postpartum in 5 and to exposure to 
various vasoactive substances in 37, mainly cannabis, selective 
serotonin-recapture inhibitors and nasal decongestants. The main pattern of 
presentation (94% of patients) was multiple thunderclap headaches recurring over 
a mean period of 1 week. In 51 patients (76%), headaches resumed the clinical 
presentation. Various complications were observed, with different time courses. 
Cortical subarachnoid haemorrhage (cSAH) (22%), intracerebral haemorrhage (6%), 
seizures (3%) and reversible posterior leukoencephalopathy (9%) were early 
complications, occurring mainly within the first week. Ischaemic events, 
including TIAs (16%) and cerebral infarction (4%), occurred significantly later 
than haemorrhagic events, mainly during the second week. Significant sex 
differences were observed: women were older, had more frequent single-drug 
exposure and a higher rate of stroke and cSAH. Sixty-one patients were treated 
by nimodipine: 36% had recurrent headaches, 7% TIAs and one multiple infarcts. 
The different time courses of thunderclap headaches, vasoconstriction and 
strokes suggest that the responsible vasospastic disorder starts distally and 
progresses towards medium sized and large arteries. No relapse was observed 
during the 16 +/- 12.4 months of follow-up. Our data suggest that RCVS is more 
frequent than previously thought, is more often secondary particularly to 
vasoactive substances, and should be considered in patients with recurrent 
thunderclap headaches, cSAH or cryptogenic strokes with severe headaches.