Teaching Case

A 40-year-old woman receiving antidepressant treatment and casual marijuana consumer, who presents in the emergency department with severe headache, vomiting, instability and visual disturbances.

She was afebrile without neurological deficit. Decreased visual acuity was noted but visual field exploration was normal. Systolic blood pressure was elevated (160/70). Lab tests were normal.

Brain CT shows multiple areas of triangular-shaped hypodensities in both parietal and occipital lobes suggestive of acute infarction. There is also noted a subtle amount of subarachnoid haemorrhage (SAH) in one sulcus of the frontal left lobe. MRI confirms the ischemic lesions, with cortical restricted diffusion and also the small amount of convexal SAH. 3D-Time of Flight (TOF) MRI angiography demonstrates a beaded appearance of middle and posterior cerebral arteries, bilaterally, showing multifocal stenosis and post-stenotic dilatations.

Three months follow up, without specific treatment, 3D-TOF MRI angiography shows a normal appearance circle of Willis.

Reversible cerebral vasoconstriction syndrome (RCVS) encompasses a group of entities such as postpartum angiopathy, Call-Fleming syndrome and drug induced angiopathy, historically considered distinct. The diagnostic criteria include acute severe headache, monophasic course, no evidence of aneurysmal SAH, normal CSF and segmental vasoconstriction of cerebral arteries which resolve within 12 weeks [1].

The pathophysiology of this syndrome remains unknown; however, alterations in cerebral vascular tone and consequent vasoconstriction are thought to be a key factor. Although can occur spontaneously, there are known triggers such as vasoactive medications, recreational drugs, pregnancy, trauma and several medical conditions [2].

RCVS most commonly affects patients between 20-50 years old with female predominance [2]. Headache is often the only symptom and it is severe in most patients, thunderclap type, sometimes excruciating. It is often associated with nausea, vomiting, photophobia and phonophobia [3].

The role of imaging includes the demonstration of cerebral vasoconstriction, evaluation of alternative diagnoses, and monitoring potential complications such as intracranial haemorrhage, vasogenic oedema, and ischemic stroke [4].

The initial non-contrast CT can be normal but in some cases, a small amount of convexal SAH or ischemic complications can be detected. At MRI, T2 and FLAIR sequences can be used to evaluate cerebral oedema while DWI is helpful in evaluating for watershed infarcts [4]. T2* can help evaluate the presence of intracranial haemorrhage [3].

CT angiography, MR angiography and catheter angiography can be used to demonstrate segmental stenosis and also exclude cerebral aneurysms or arterial dissection. A “beaded” appearance with multifocal areas of narrowing alternating with normal segments is typical. If vessel wall imaging is performed, it is possible to identify short-segment arteries wall thickening usually without wall enhancement [4].

Symptomatic treatment should be started early if clinical findings are consistent: removal of precipitating factors and management of blood pressure and analgesics for headache, avoiding triptans and indomethacin. Calcium channel blockers have been used against vasospasm. In patients with refractory cerebral vasoconstriction, endovascular treatment may be helpful, including direct intraarterial administration of vasodilator drugs and intracranial angioplasty [5].

RCVS has a good prognosis. It typically follows a self-limiting, monophasic course, with the resolution of symptoms by 3 weeks and no new symptoms after 1 month. Ischemic infarcts will determine the long-term prognosis [2,3].

Written informed patient consent for publication has been obtained.