Brain Magnetic Resonance Imaging Findings in Patients With Mitochondrial Cytopathies

Background Mitochondrial cytopathies (MCs) are a heterogeneous group of clinical entities, some of which have classic phenotypes. Magnetic resonance imaging (MRI) has been reported to be helpful in the diagnosis of MC. Objective To correlate the most common brain MRI findings reported in patients with MC with the clinical findings in patients in different MC subgroups. Design Case series. Setting Patients with MCs seen at the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico. Patients Twenty-one patients with MC with the following phenotypes: chronic progressive external ophthalmoplegia (n = 7), Kearns-Sayre syndrome (n = 7), mitochondrial neurogastrointestinal encephalopathy (n = 6), and myoclonic epilepsy with ragged red fiber myopathy (n = 1). Results Brain MRI abnormalities were found in 20 (95%) of 21 patients. The most frequent abnormalities were widespread white matter hyperintensity in 19 patients (90%), supratentorial cortical atrophy in 18 patients (86%), and cerebellar atrophy in 13 patients (62%). Widespread white matter hyperintensity ( P P  = .001) were each correlated significantly with MC. Subsequent subgroup analyses showed that the absence of basal ganglia hyperintensity was correlated with Kearns-Sayre syndrome ( P P  = .005). Conclusions The presence of widespread white matter hyperintensity and/or supratentorial cortical atrophy in brain MRI may help to establish the diagnosis of MC. The radiologist has a role to play in the workup of MC by confirming the diagnosis and possibly distinguishing different subgroups of MC.