Abstract：ObjectiveTo explore the clinical,electrophysiological and imaging characteristics of a case of mitochondrial encephalomyopathy with lactic academia and strokelike episodes (MELAS) syndrome mimicking an autoimmune encephalitis and summarize the treatment process.MethodsThe pathogenesis and clinical data one case of MELAS syndrome mimicking an autoimmune encephalitis was analyzed retrospectively,and relevant literatures were reviewed.ResultsThe patient was admitted to hospital for fever,headache,nausea,vomiting,blurred vision,eye myoclonus,ataxia and other symptoms twice 3 and 6 months ago,and misdiagnosed as viral encephalitis and autoimmune encephalitis.The symptoms gradually improved after treatment and discharged.The patient was transferred to our hospital for the third time,because of blurred vision and difficult walking.Routine examination of cerebrospinal was performed and anti-N-methyl-D-aspartate receptor (NMDAR) antibody was negative.EEG showed the right side of the occipitalia,posterior temporal distributed a large number sporadic-paroxysmal spikes/spike slow wave complex,spike/sharp slow wave complex,which could be spread to the top of the right side.MRI showed temporal gyrus was markedly swollen,sulci was narrower and lighter.DWI showed high signal,local softening in the left temporal occipital cortex,genetic testing showing A3243G mutation,eventually diagnosed as MELAS syndrome.ConclusionChildren whose clinical symptoms resemble autoimmune encephalitis,should be given further examination to rule out or confirm the diagnosis of MELAS syndrome in case of illness instability and recurrent symptoms.
