Oculopharyngeal muscular dystrophy

Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant neuromuscular disease which appears in early middle age (sixth decade). It is caused by a mutation in the PABPN1 gene.

Signs and symptoms
Progressive ptosis (drooping of eyelids)and weakness of the extraocular muscles is the initial clinical finding which continues until paralysis of all eye movements occurs; however, pupillary reactions remain unaffected. Dysphagia (difficulty swallowing), facial weakness and proximal limb weakness develops later on in the disease.

Diagnosis
A muscle biopsy reveals abnormal vacuoles within muscle fibres. A distinction between OPD and myasthenia gravis or mitochondrial myopathy must be made. The absence of family history and the fluctuation of symptoms in myasthenia gravis usually distinguish the two conditions.

Treatment
Treatment is supportive to the patient with death eventually occurring from infections. Difficulty with swallowing may result in nasogastric feeding.