Boys and girls are affected equally. CPEO and pigmentary retinopathy appear before age 20. Ophthalmoplegia generally precedes the development of cardiac conduction disturbances. Sudden death may occur from these disturbances, and patients should have regular cardiac exams, regardless of age. Weakness of somatic muscles often is noted with progressive facial muscle weakness and neck and shoulder weakness.
Extremities tend to be involved to a lesser degree.
Pallor of the optic disc, attenuation of retinal vessels, visual field defects, and posterior cataract formation common to retinitis pigmentosa rarely, if ever, occur. The table in Picture 1 may be helpful for categorizing physical findings. Increased aldolase Increased protein in CSF Thyroid studies can confirm suspicion of Graves disease. A positive acetylcholine receptor antibody test may establish the diagnosis of myasthenia gravis. A negative acetylcholine receptor antibody assay does not differentiate CPEO from myasthenia gravis.