Fibromuscular dysplasia (FMD) is a rare vascular disease characterized by abnormal cell growth in the walls of medium-sized arteries, leading to narrowing, aneurysms, or dissections. It most commonly affects the renal and carotid arteries but can involve other vessels. FMD predominantly occurs in women, typically between ages 20 and 60, though it can affect men and other age groups.

Key Features:

• Types:
• Medial fibroplasia (most common, ~80%): “String of beads” appearance on imaging due to alternating areas of narrowing and dilation.
• Intimal fibroplasia (~10%): Smooth, focal narrowing.
• Adventitial fibroplasia (rare): Affects outer artery layer.
• Symptoms: Depend on affected arteries:
• Renal arteries: Hypertension, kidney dysfunction.
• Carotid/vertebral arteries: Headaches, pulsatile tinnitus, dizziness, stroke, or transient ischemic attack.
• Other sites: Abdominal pain (mesenteric arteries), limb claudication (peripheral arteries).
• Asymptomatic cases are common, detected incidentally.
• Complications: Aneurysms, arterial dissections, stroke, kidney failure.

Diagnosis:

• Imaging:
• Catheter-based angiography (gold standard).
• Non-invasive: CT angiography, MR angiography, or Doppler ultrasound.
• “String of beads” pattern is hallmark for medial FMD.
• Clinical evaluation: History, physical exam, and ruling out other causes (e.g., atherosclerosis, vasculitis).

Treatment:

• Medical:
• Anti-hypertensive drugs (e.g., ACE inhibitors) for renal FMD.
• Antiplatelet therapy (e.g., aspirin) to reduce clot risk.
• Symptom management (e.g., headache relief).
• Interventional:
• Angioplasty (balloon dilation) for significant stenosis.
• Stenting is rarely used.
• Surgery for aneurysms or complex cases.
• Lifestyle: Smoking cessation, blood pressure control, regular follow-up.

Prognosis:

• Varies by severity and location. Many patients live normal lives with proper management.
• Regular imaging follow-up is critical to monitor progression.

Notes:

• Cause is unknown, but genetics, hormonal factors, and environmental triggers may play a role.
• Associated with spontaneous coronary artery dissection (SCAD) in some cases.
• Patient registries (e.g., US Registry for FMD) and organizations like the Fibromuscular Dysplasia Society of America provide support and research updates.

Disclaimer: owerl is not a doctor; please consult one.