Min Li, Yinbao Hu
This case highlights that FMD should be considered in the differential diagnosis of ischemic stroke in middle-aged patients, including men, even in the presence of traditional vascular risk factors. The coexistence of FMD with multiple metabolic disturbances in this case, while likely coincidental, underscores the complexity of stroke etiology and the importance of a comprehensive diagnostic approach that does not prematurely attribute stroke to common risk factors alone. Carotid FMD, though rare, is a treatable cause of stroke, and early diagnosis via DSA can guide appropriate management to prevent recurrence.
BACKGROUND: Fibromuscular dysplasia (FMD) is a rare, non-atherosclerotic, non-inflammatory vascular disease that predominantly affects women and can lead to stenosis, dissection, aneurysm, or occlusion of medium-sized arteries. Cerebrovascular FMD is an important but underrecognized cause of ischemic stroke, particularly in young to middle-aged adults.
CASE PRESENTATION: A 42-year-old man presented with acute-onset slurred speech and right-sided weakness. Brain magnetic resonance imaging (MRI) was precluded by claustrophobia, but serial non-contrast head CT scans (admission and 48-hour) confirmed an acute ischemic infarct in the left basal ganglia. Intravenous thrombolysis with alteplase was administered within the therapeutic window. Cervicocerebral computed tomography angiography (CTA) revealed a typical "string-of-beads" sign in the left internal carotid artery (L-ICA) C1 segment, suggestive of FMD, which was subsequently confirmed by digital subtraction angiography (DSA). Subsequent laboratory workup revealed multiple metabolic abnormalities: severe hypertriglyceridemia (17.54 mmol/L), hyperuricemia (569 μmol/L), elevated liver enzymes (ALT 152 U/L, AST 128 U/L), and newly diagnosed diabetes mellitus (HbA1c 7.2%). Extensive autoimmune and thrombophilia panels were negative. DSA demonstrated the characteristic "string-of-beads" appearance in the mid-cervical segment of the L-ICA, pathognomonic for the medial fibroplasia subtype of FMD. The patient was managed with dual antiplatelet therapy, high-intensity statin, blood pressure control and risk factor modification. He showed gradual neurological improvement and was discharged on day 14 with a modified Rankin Scale score of 1. At the 3-month follow-up, his neurological function had fully recovered (mRS 0), with no recurrent events. Blood pressure was well-controlled, and laboratory tests showed normalized lipid and glucose profiles. Renal artery duplex ultrasound at 3 months revealed no evidence of FMD.
CONCLUSION: This case highlights that FMD should be considered in the differential diagnosis of ischemic stroke in middle-aged patients, including men, even in the presence of traditional vascular risk factors. The coexistence of FMD with multiple metabolic disturbances in this case, while likely coincidental, underscores the complexity of stroke etiology and the importance of a comprehensive diagnostic approach that does not prematurely attribute stroke to common risk factors alone. Carotid FMD, though rare, is a treatable cause of stroke, and early diagnosis via DSA can guide appropriate management to prevent recurrence.