Chronic progressive external ophthalmoplegia vs. myasthenia gravis – case report and review of literature

Abstract

The mitochondrial myopathy consists of a heterogeneous group of conditions characterized by primary disfunction of mitochondrial respiratory chain causing muscle disease. Chronic progressive external ophthalmoplegia is a frequent mitochondrial disorder that shares clinical, enzymatic and genetic features with other mitochondrial diseases. We present a case of a patient who was initially diagnosed with myasthenia gravis, did not respond to specific therapy and was subsequently diagnosed by clinical, biochemical and histopathological criteria with a mitochondrial myopathy. A 37 years old woman, suspected and treated for myasthenia gravis presented with ptosis, marked fatigue, muscle weakness and myalgia, symptoms that progressively got worse despite the anticholinesterase therapy. Knowledge of this entity allows us to avoid unnecessary treatment and deferral of the real diagnosis.

Keywords

• chronic progressive external ophthalmoplegia
• mitochondrial myopathy
• ragged-red fibers
• ragged-blue fibers
• myasthenia gravis