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.

Stroke is the third leading cause of death, and vascular dementia the second cause of dementia after Alzheimer's disease. CADASIL (for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) causes a type of stroke and dementia whose key features include recurrent subcortical ischaemic events and vascular dementia and which is associated with diffuse white-matter abnormalities on neuroimaging. Pathological examination reveals multiple small, deep cerebral infarcts, a leukoencephalopathy, and a non-atherosclerotic, non-amyloid angiopathy involving mainly the small cerebral arteries. Severe alterations of vascular smooth-muscle cells are evident on ultrastructural analysis. We have previously mapped the mutant gene to chromosome 19. Here we report the characterization of the human Notch3 gene which we mapped to the CADASIL critical region. We have identified mutations in CADASIL patients that cause serious disruption of this gene, indicating that Notch3 could be the defective protein in CADASIL patients.