What is Facioscapulohumeral Muscular Dystrophy?

Facioscapulohumeral muscular dystrophy (FSHMD) is a muscle condition that induces the progressive loss of muscle function. Also known as Landouzy-Dejerine muscular dystrophy, FSHMD is a neuromuscular disorder that initially presents as impaired muscle function central to the upper body, including the shoulders and arms. There is no cure for FSHMD. Due to the disease’s gradual progression, treatment generally involves the use of physical therapy and medication to help prolong one’s ability to remain mobile.

Considered an autosomal dominant disorder, facioscapulohumeral muscular dystrophy is caused by the presence of a dominant protein mutation carried by an autosome, or nonsex chromosome. The passage of the mutated dystrophin protein gene is dependent on one parent being a carrier. A child that inherits the mutated gene possesses a 50/50 chance for developing facioscapulohumeral muscular dystrophy or a related myotonic disorder.

In most cases, familial history plays a pivotal role in a diagnosis of facioscapulohumeral muscular dystrophy. Following an extensive consultation and physical examination, a battery of diagnostic tests are generally ordered to confirm a diagnosis. Blood tests are administered to detect the presence of specific enzymes associated with muscle inflammation and deterioration, as occurs with muscular dystrophy (MD). A muscle biopsy and electromyography may also be performed to determine the presence of markers indicative of MD and evaluate any abnormalities in the electrical activity of one’s muscles.

Symptoms associated with this form of MD generally present in adolescence. Individuals often exhibit poor facial muscle control, such as an inability to blink properly, close one’s eyes, or move one’s lips. Progressive muscle atrophy initially affects the upper torso and, with time, descends to affect one’s hips. Eventually, muscles in the lower limbs begin to atrophy, jeopardizing mobility. Though symptom presentation may be patterned, its severity can vary depending on the rate of disease progression.

In the absence of a cure for facioscapulohumeral muscular dystrophy, treatment is centered on prolonging one’s mobility. Medications, such as corticosteroids, are utilized to control and prevent muscle spasms, known as myotonia, and deterioration. Individuals may be outfitted with braces that offer support and promote flexibility in one’s limbs.

Physical therapy is the cornerstone of nearly all MD therapies and is utilized to stave off the effects of muscle weakness and joint deterioration. As muscles shorten and lose their flexibility, a process known as contracture, one’s ability to move becomes severely compromised. The goal of physical therapy is to nurture one’s range of motion and joint flexibility in an effort to delay contracture onset. Individuals who develop severe contracture may undergo surgery, known as tendon release surgery, to alleviate discomfort in areas such as the spine, hips, and lower limbs.