The part that connects to the clavicle is less often affected. This muscle wasting pattern can contribute to a prominent horizontal anterior axillary fold. Beyond this point the disease does not progress further in 30% of familial cases. After upper torso weakness, weakness can "descend" to the upper arms (biceps muscle and, particularly, the triceps muscle). The forearms are usually spared, resulting in an appearance some compare to the fictional character Popeye, although when the forearms are affected in advanced disease, the wrist extensors are more often affected. Lower body and trunk
After the upper body, weakness can next appear in either the pelvis, or it "skips" the pelvis and involves the tibialis anterior (shin muscle), causing foot drop. One author considers the pelvic and thigh muscles to be the last group affected. Pelvic muscle weakness can manifest as pelvic tilt, causing the hips to be held in slight flexion. Pelvic weakness can also cause a Trendelenburgs sign. Weakness of the back of the thigh (hamstrings) is more common than weakness of the front of the thigh (quadriceps).Weakness can also occur in the abdominal muscles and paraspinal muscles, which can manifest as a protuberant abdomen and lumbar hyperlordosis. Abdominal weakness can cause inability to do a sit-up or the inability to turn from one side to the other while lying on ones back. Of the rectus abdominis muscle, the lower portion is preferentially affected, manifesting as a positive Beevors sign.
This test is rarely indicated. Muscle MRI is sensitive for detecting muscle damage, even in mild cases. Because of the particular muscle involvement patterns of FSHD, MRI can help differentiate FSHD from other muscle diseases, directing genetic testing. Differential diagnosis
Included in the differential diagnosis of FSHD are limb-girdle muscular dystrophy (especially calpainopathy), scapuloperoneal myopathy, mitochondrial myopathy, Pompe disease, and polymyositis. Calpainopathy and scapuloperoneal myopathy, like FSHD, present with scapular winging. Features that suggest FSHD are facial weakness, asymmetric weakness, and lack of benefit from immunosuppression medications. Features the suggest an alternative diagnosis are contractures, respiratory insufficiency, weakness of muscles controlling eye movement, and weakness of the tongue or throat. Management
No intervention has proven to significantly slow progression of weakness or improve strength. Screening and monitoring of complications
The American Academy of Neurology (AAN) recommends several medical tests to detect complications of FSHD. A dilated eye exam to look for retinal abnormalities is recommended in those newly diagnosed with FSHD; for those with large D4Z4 deletions, an evaluation by a retinal specialist is recommended yearly. A hearing test is recommended for individuals with early-onset FSHD prior to starting school, or for any other FSHD-affected individual with symptoms of hearing loss. Pulmonary function testing (PFT) is recommended in those newly diagnosed to establish baseline pulmonary function, and recurrently for those with pulmonary insufficiency symptoms or risks. Routine screening for heart conditions, such as through an electrocardiogram (EKG) or echocardiogram (echo), is considered unnecessary in those without symptoms of heart disease.