Reversible cerebral vasoconstriction syndrome (RCVS)is a group of conditions with a common clinical and radiologic presentation. It is characterized by thunderclap headache and reversible vasoconstriction of the cerebral arteries.
On this page:
Article:
- Terminology
- Epidemiology
- Diagnosis
- Clinical presentation
- Radiographic features
- Treatment and prognosis
- History and etymology
- Differential diagnosis
- Practical points
- References
Images:
- Cases and figures
- Imaging differential diagnosis
Terminology
Numerous and varied terms have been used to describe RCVS, sometimes entirely synonymously and at other times one or other subset. These terms include 1,2,4,17:
acute benign cerebral angiopathy
benign angiopathy of the CNS
CNS pseudovasculitis
Call-Fleming syndrome
cerebral vasculopathy
drug-induced cerebral arteritis
isolated benign cerebral vasculitis
migrainous vasospasmor migraine angiitis
postpartum cerebral angiopathy
primary thunderclap headache
sexual headache
thunderclap headache associated vasospasm
vasospasm in fatal migrainous infarction
Epidemiology
RCVS affects women more commonly than men (F:M = 2.4:1) and usually presents between 20-50 years of age (mean 42 years), although it has also been described in children and adolescents 17. The mean age of presentation in men is a decade younger than the mean age of presentation in women.
Associations
pregnancy and puerperium
eclampsia, pre-eclampsia
exposure to drugs and blood products
phenylpropanolamine
pseudoephedrine
ergotamine
tartrate
methysergide
bromocriptine
lisuride
SSRI
sumatriptan
isometheptene
recreational drugs
marijuana, sympathomimetics
tacrolimus
cyclophosphamide
erythropoietin
intravenous immunoglobulin
red blood cell transfusion
miscellaneous
migraine (20-40%)14
hypercalcemia
porphyria
pheochromocytoma
bronchial carcinoid
unruptured cerebral aneurysm
head trauma/neurosurgical procedures
spinal subdural hematoma
post carotid endarterectomy
idiopathic
Diagnosis
In 2016, a study proposed a set of criteria to diagnose RCVS and to distinguish it from primary angiitis of the central nervous system (PACNS) with a specificity of 98-100% and a similarly high PPV 7:
recurrent thunderclap headaches or;
single thunderclap headache with either normal neuroimaging study or watershed infarct/vasogenic edema or;
no thunderclap headache but abnormal angiographic findings with a normal neuroimaging study
this basically rules out primary angiitis of the central nervous system as neuroimaging is always abnormal
Criteria have also been proposed by the International Headache Society.
Clinical presentation
Thunderclap headacheis the usual primary symptom,often occipital but also potentially diffuse. They are usually fairly short in duration (a few hours) and usually, headaches will periodically recur over days or weeks 1,2,17.
Headaches may be associated with photophobia, nausea and vomiting.Focal neurological deficits can occur, secondary to ischemia or convexity subarachnoid hemorrhage. CSF studies are normal or near normal.
Radiographic features
Neuroimaging is often reported as normal at the onset of symptoms but this varies from study to study (21-55%) 2,6.
The findings on imaging consist of either direct visualization of the vascular narrowings and/or complications related to vascular narrowings such as:
convexity subarachnoid hemorrhage (~20%)2,6,17,18
lobar intracerebral hemorrhage (~7%)2,6,18
ischemic stroke (including watershed infarct) (~16%) 6,18
vasogenic edema (38%)6
Ultrasound
Transcranial Doppler may show increased arterial velocities suggesting vasospasm and decreased luminal caliber of ICA, MCA, and ACA 8. Bedside ultrasound has been used for the follow-up of vasospasm 9.
CT
CT is useful to rule out aneurysmal subarachnoid hemorrhage. As previously noted, a CT scan can be entirely normal with RCVS. The following can be seen:
convexity subarachnoid hemorrhage
ischemic stroke, including watershed infarct
lobar intracerebral hemorrhage
vascular narrowings on CTA
MRI
Cortical edema and/or vascular FLAIR hyperintensities may precede vasoconstriction on MRI.
T2/FLAIR
sulcal hyperintensities may reflect convexity subarachnoid hemorrhage or vascular hyperintensities (an early sign)11
cortical hyperintensities related to cortical edema (an early sign)11
vasogenic edema related to vasoconstriction or cytotoxic
T2/FLAIR C+ (Gd)
useful as it does not show normal cortical vessels and meninges (versus T1 C+), and may reflect blood-brain barrier breakdown 12
variable patterns ofsulcal enhancement have been described12
MRA:vascular narrowings can be seen (see DSA)
DWI:watershed infarcts can be seen
Vessel wall MRI (VW-MRI) may be a useful adjunct to conventional MRI, allowing differentiation between RCVS,where there is no or mild contrast enhancement of the affected arterial wall, and other causes of vascular narrowing such as vasculitis,where there is intense contrast enhancement of the affected arterial wall,or intracranial atherosclerotic plaques, which focally demonstrate contrast enhancement 16.
Angiography (DSA)
Smooth, tapered narrowings involving large to medium-sized arteries followed by abnormally dilated segments of second-order and third-order branches is the most characteristic finding 13. This dilatation gives the typical beaded or sausage-shaped appearance of cerebral arteries.Normalization of the angiographic findings is usually seen within 8-12 weeks 6,12.
Vasoconstriction following subarachnoid hemorrhageinvolves longer segments of more proximal branches without alternating areas of narrowing 13.It is worth noting that intracranial atherosclerosis causing vascular narrowings is seen in 8-30% of the asymptomatic population thus potentially complexifying evaluation on DSA 12.
Treatment and prognosis
Spontaneous resolution usually occurs, with improvement in angiographic findings within three months. The natural history of the condition has not however been well characterized. Complete long-term resolution of the symptoms with no neurological deficit is the most common outcome in up to 90% of patients 6.
Although no randomized controlled trials are available, treatment with calcium channel blockers (e.g. nimodipine, verapamil) seems to be efficacious and are thought to be a reasonable first-line therapy 19.
History and etymology
It was first described by Calabrese et al. in 1993 and named “benign angiopathy of the central nervous system”. Afterwards, in 1998,Call and Flemming described a series of patients with severe headaches and reversible cerebral segmental vasoconstriction (see Call-Flemming syndrome)15. The term RCVS was coined later in 2007 by Calabrese 1.
Differential diagnosis
The presentation of RCVS is most commonly a recurrent thunderclap headache, with the following disorders commonly considered in the differential diagnosis:
aneurysmalsubarachnoid hemorrhage.
intracerebral hemorrhage
cervical artery dissection
internal carotid artery dissection
vertebral artery dissection
cerebral venous thrombosis
When vascular imaging has been obtained, the differential narrows to conditions that can cause intracranial arterial beading, namely:
subarachnoid hemorrhage with intracranial vasospasm
primary angiitis of the central nervous system (PACNS)
arterial dissection
RCVS may co-exist with posterior reversible encephalopathy syndrome (PRES).
Practical points
No validated radiological criteria have been defined for diagnosis confirmation. However, the following guidelines are reasonable when applied to the clinical context:
neurovascular imaging demonstrates multifocal narrowings in the circle of Willisand its branches
there is a suggestion of centripetal propagation of the narrowings when comparing initial neurovascular imaging at the onset of thunderclap headache with postremission neurovascular imaging 5
if a subarachnoid hemorrhage is present, it is usually mild and only involves the cerebral convexity
validation of the diagnosis rests on the eventual resolution of neurovascular findings within 8-12 weeks 6-14
