Fibromuscular Dysplasia, commonly called FMD, is a disease that causes one or more arteries in the body to have abnormal cell development in the artery wall. As a result, areas of narrowing (called stenosis), aneurysms, or tears (called dissections) may occur. If narrowing or a tear causes a decrease in blood flow through the artery, symptoms may result. Many people with FMD do not have any symptoms or signs on physical examination and are diagnosed by accident during a radiology scan for another problem.
FMD is most commonly found in the arteries that supply the kidneys with blood (renal arteries) and the arteries called the carotid and vertebral arteries which are found in the neck and supply the brain with blood. Less commonly, FMD affects the arteries in the abdomen (supplying the liver, spleen and intestines) and extremities (legs and arms). In more than one-half of people with this disease, there will be evidence of FMD in more than one artery.
What causes FMD?
The cause of FMD is not yet known, but several theories have been suggested. A number of case reports in the literature have identified the disease in multiple members of the same family including twins. As a result, it is felt that there may be a genetic cause. However, a relative may have different artery involvement, different disease severity, or not develop FMD at all. In fact, most individuals with FMD do not have a family member who also has the disease. Among some individuals with FMD, there is a family history of other vascular problems, such as blood vessel aneurysms.
FMD is far more commonly seen in women than in men, resulting in the theory that hormones may play an important role in disease development. However, in small population studies, one's reproductive history (number of pregnancies and when they occurred) as well as the use of birth control pills did not correlate with the development of FMD.
Other possible causes of FMD include abnormal development of the arteries that supply the vessel wall with blood, resulting in inadequate oxygen supply; the anatomic position or movement of the artery within the body, certain medications, and tobacco use. It is possible that many factors contribute to the development of FMD. This area requires further research and is under investigation by many researchers around the world.
What are the signs and/or symptoms of FMD?
Some people with this disease do not have symptoms or findings on a physical examination. The signs and/or symptoms that a person with FMD may experience depend on the arteries affected and whether there is evidence narrowing, tears, or aneurysms within those affected arteries. Any pain or clinical sign related to FMD typically comes from the organ that is supplied by that artery. For example, FMD in the renal arteries may cause high blood pressure. FMD in the carotid arteries may cause headaches or a swooshing sound in the ears (called pulsatile tinnitus). Some patients with FMD may have no symptoms at all but are diagnosed with this disease when a physician hears a noise over one of the arteries due to disturbed or turbulent blood flow within the vessel. This noise is known as a bruit. Please click here to view an arterial map.
Potential Symptoms and Signs of FMD
FMD of Renal Arteries (Kidney):
High blood pressure [>140/90 mmHg]
Abnormal kidney function as detected on blood tests
Flank pain from dissection or infarction of the kidney
Kidney failure (rare)
Atrophy (shrinkage) of the kidney
FMD of Carotid Arteries:
Bruit (noise) heard in neck with stethoscope
Swooshing sound in ear
Ringing of the ears
Vertigo (room spinning)
Transient ischemic attack
A person with severe carotid FMD causing severe narrowing or a tear in the carotid or vertebral artery may have neurologic symptoms involving the facial nerves (drooping of the eye lid, unequal size of the pupils, for example), stroke, or transient ischemic attack. People with carotid FMD have a higher risk for aneurysms of the arteries in the brain (intracranial aneurysms). Bleeding in the brain (intracranial hemorrhage) may occur if an aneurysm ruptures, and it is important to identify and treat brain aneurysms early to prevent this.
FMD involving the arteries that supply the intestines, liver and spleen with blood (mesenteric arteries) can result in abdominal pain after eating and unintended weight loss. FMD in the arms and legs can cause limb discomfort with exercise or can lead to unequal blood pressure in the arms.
Fibromuscular Dysplasia took our Livia. We didn't have warning signs, we didn't have time for a proper diagnosis. FMD is extremely hard ot diagnose, especially the type that Livia had. It is our goal someday to make diagnosing FMD streamline and accessible to everyone. Due to this unavailability in diagnosis, Mason is not able to be diagnosed with this, or the lack of FMD. It would be peace of mind if there were such a treatment or test for intracranial FMD like Livia had. Please consider donating to FMD in hopes for someday, a better treatment, diagnosis and cure. In loving memory of Livia, we will search for a better tomorrow for all those who suffer with FMD.
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