Clinical and imaging manifestations of adult mitochondrial encephalomyopathy

Abstract

Objective To investigate clinical manifestations and neuroimaging in the adult patients with mitochondrial encephalomyopathy (ME). Methods Systematic study was performed on the clinical features of six adult patients with ME with observations on electromyogram(EMG), electroencephalogram(EEG), the blood lactic acid level,muscle biopsies results and neuroimaging features of CT and MRI. Results The main clinical features were characterized by seizures, intolerance to exercise, audio-visual dysfunction, mental retardation, and so forth. EMG showed neurogenic damages(4/5 cases); EEG showed extensive mild to severe abnormal activities(3/3 cases)and lactic acidosis was also observed(4/4 cases). Neuroimaging findings included symmetric supratentorial multifoci lesions, located in frontal, temporal, parietal, and occipital lobes, thalami and basal ganglia with widening of ventricles and cerebral atrophy; the neuroimaging findings also included hyperintensity on T_2-weighted images and hypointensity/isointensity on T_1-weighted images; No stenosis and occlusion of main artery was displayed by magnetic resonance angiography(MRA). Muscle biopsies showed red ragged fiber (RRF)(4/6 cases). Conclusions Based on clinical features and neuroimaging, diagnosis of ME in early stage may be made in combination with muscle biopsy.