Clinical and pathological features of chronic progressive external ophthalmoplegia

Objective To investigate the clinical and pathological features of chronic progressive external ophthalmoplegia(CPEO).Methods The clinical data of 7 cases of CPEO were analyzed retrospectively.Results All the patients showed chronic progressive ptosis,6 patients showed dysfunction in eye movements.There was a patient who had dysphagia and limb weakness at 16 years after onset.All the patients were examined by EMG,and the results showed neurogenic changes in 1 case.And the pathological detection showed that 7 patients were all with typical ragged red fibers(RRF),besides 2 cases had incremental lipid in some muscle fiber,and 2 cases showed Type Ⅰ,Ⅱ fiber distribution anomaly with fiber type grouping phenomenon.Two patients in the group were observed by electron microscopy,which showed the accumulation of abnormal mitochondrias beneath the sarcolemma and between the myofibrils.Conclusions CPEO is a kind of mitochondrial encephalomyopathies with the major clinical manifestations like chronic progressive ptosis and dysfunction in eye movements.It is easy to be diagnosed as ocular myasthenia gravis,oculopharyngeal muscular dystrophy or eye diseases in clinical.RRF and accumulation of abnormal mitochondrias are pathologic clues for the diagnosis of CPEO.