Subacute Necrotizing Encephalopathy in a Pig-tailed Macaque (Macaca nemestrina) That Resembles Mitochondrial Encephalopathy in Humans

摘要

Amalepig-tailedmacaque(Macacanemestrina),approximately5yearsold,wasfoundtobevision-impairedandtohaveprofoundbehavioralabnormalities,includinghyperactivityandself-injuriousbehaviorthatwasnotamenabletoameliorationbyenvironmentalenrichment.Facialandskeletaldysmorphismsalsowerenoted.Magneticresonanceimaging(MRI)andpositronemissiontomography(PET)scanningrevealedareasofpossibleinfarctionintheoccipitallobesandmegaventriculosis.Atnecropsy,followingeuthanasiaforhumanereasons,severepolio-andleukoencephalomalaciaaccompaniedbymegaventriculosiswereseeninbothoccipitallobesandinseveralsulcioftheparietalandfrontallobes.Lightmicroscopicfindingsincludedlossofneocorticalstructure,withnecrosis,neuronalloss,astrogliosis,vascularproliferation,mildspongiosis,anddemyelination.Theextentandseverityoflesionsweremostpronouncedintheoccipitallobesandweregreaterintheleftthanintherighthemisphere.Otherlesionsincludedmildbilateralatrophyoftheopticnerves,thymicinvolution,necrotizingdermatitisduetotrauma,andaspectrumofspermatozoalabnormalities.Theimagingandgrossandlightmicroscopicchangesfoundinthisanimalresemblethemitochondrialencephalopathiesofhumans;thiswascorroboratedbyresultsofimmunohistochemicalanalysisdemonstratingdecreasedexpressionofenzymesofthemitochondrialoxidativecomplex([OC]-I,-III,and-IV)inbrainandmuscle,anddetectionoffibrinogenimmunoreactivityinneuronsandglialcells.Thespermatozoaldefectsmayrepresentyetanotheraspectofamitochondrialdefect.