What is Oculopharyngeal Muscular Dystrophy (OPMD)?
OPMD IS a rare, slowly progressive myopathy characterized by weakness of the eyelids (ocular) and throat (pharyngeal) muscles, resulting in drooping of the eyelids, trouble moving the eyes and/or difficulty swallowing.
Symptoms of OPMD usually do not begin until the mid-40s or 50s, but can occur earlier. The weakness progresses slowly.
Typical symptoms include:
- Droopy eyelids
- Difficulty swallowing
Other associated symptoms include:
- Tongue weakness
- Proximal and distal muscle weakness
- Facial muscle weakness
Causes and Inheritance
OPMD is caused by an abnormal expansion of trinucleotide repeats in the gene PABPN1, which leads to the production of a nonfunctional protein that forms clumps in the muscle cells. OPMD is usually inherited in an autosomal dominant pattern, and in rare cases, may show a recessive pattern of inheritance.
A diagnosis of OPMD may be suspected based upon clinical evaluation, a detailed patient history, and identification of characteristic findings, such as droopy eyelids, difficulty swallowing, and difficulty speaking. However, as the clinical features of OPMD overlap with features of several other neuromuscular diseases, it is challenging to make a diagnosis just based on clinical features. Genetic testing of the PABPN1 gene can confirm the diagnosis.
Treatment of OPMD mainly focuses on the specific symptoms in each individual. Severe drooping of the eyelid may be treated with plastic surgery. Nonsurgical and surgical procedures may help with difficulty swallowing. Assistive devices and occupational therapy may help those with difficulty walking.