We are discussing a case of a 35-year-old female with fibromuscular dysplasia involving the craniocervical circulation who presented with an acute ischaemic stroke. The incidence of stroke in adults younger than 45 years ranges from 3.4 to 11.3 per 100,000 people per year (2). Recent studies suggest that the incidence of fibromuscular dysplasia involving the craniocervical vasculature is less than 0.02% (2).
Histology suggests that defective transformation of smooth muscle fibroblasts leads to degradation of elastic laminae, aberrant collagen synthesis, and segmental fibroplasia (4). Unlike in atherosclerotic disease, fibromuscular dysplasia involves middle and distal arterial segments (5). It could lead to arterial stenosis, occlusion, aneurysm, dissection, and arterial tortuosity. Smoking is now considered a potential contributing factor and portends a worse prognosis (2).
Although differential diagnoses for young females with stroke are vast, by the radiological imaging and the physical examination, the probable causes can be narrowed down where vasculopathy (such as arterial dissection), cardiac defects, recent pregnancy, other hypercoagulable states, smoking, illicit drug use, premature atherosclerosis, hypertension, low physical activity, metabolic disorders, migraine, and cases of focal cerebral arteriopathy need to be considered (6).
In this patient, non-contrast CT brain gave the first objective evidence of hemorrhagic infarction. The MRI angiogram of the craniocervical vasculature suggested vasculopathic etiology of fibromuscular dysplasia because of the apparent beading of the left internal carotid, middle cerebral, and anterior cerebral arteries. Fibromuscular dysplasia could be focal or multifocal. About 90% of patients have a multifocal disease, leading to the characteristic ‘string of beads’ appearance, which was seen in our patient. Although catheter-based angiography is considered the gold standard for diagnosis, it is not routinely practiced (3). Digital subtraction angiography is performed with high clinical suspicion and to treat with revascularization for stenosis (6). For FMD, there is no established corrective therapy up to date, but fortunately, it has a more benign course in asymptomatic individuals. Patients presenting with ischemic stroke should be evaluated to determine eligibility for reperfusion therapy with intravenous thrombolysis or mechanical thrombectomy (6). Young stroke evaluation should include cerebral angiography to diagnose fibromuscular dysplasia and arterial dissection, vasculitis, and aneurysms, which are significant aetiologies for stroke in this population (3).
Management of cerebrocortical FMD mainly depends on the presenting symptoms and any associated neurologic complications such as carotid artery dissection, migraine, or aneurysm. Acute stroke in patients with FMD should follow standard stroke guidelines where it is not a contraindication to fibrinolytic therapy or mechanical thrombectomy in otherwise eligible cases. However, antiplatelet therapy may be preferred in carotid artery dissection because of safety and convenience, where studies have shown no benefit of anticoagulation over antiplatelet therapy (7). Based on the clinical experience of the treating physician and other patient factors, comorbid conditions, and tolerance of these agents, the choice between antiplatelet and anticoagulation varies. Considering the risk of bleeding into the previous cerebral infarction with anticoagulation, we commenced antiplatelet therapy for our patient. Although a repeat imaging is suggested in three to six months to assess the status of the arteries affected by dissection, our patient defaulted the follow-up.