Levator palpebrae biopsy and diagnosis of progressive external ophthalmoplegia.
BACKGROUND
Progressive external ophthalmoplegia (PEO) is a mitochondrial myopathy of ocular muscles. Diagnostic investigation usually involves limb skeletal muscle biopsy and molecular genetic studies, although diagnostic yield tends to be low. The purpose of this study was to evaluate the diagnostic yield obtained by analysis of levator palpebrae (LP) muscle tissue.


METHODS
This is a clinicopathologic study of 8 patients with a diagnosis of PEO, who had LP muscle biopsies as part of oculoplastic procedures. Six of these patients also had limb muscle biopsies. Histopathology, electron microscopy and genetic studies were performed.


RESULTS
Diagnostic histopathologic findings were present in 4/6 quadriceps biopsies, and 7/8 LP biopsies. Genetic testing on DNA extracted from LP muscle revealed abnormalities in 4 patients.


CONCLUSIONS
In patients whose LP. muscle demonstrate both genetic defects and histopathological abnormalities, the diagnosis of PEO can be confirmed without limb muscle biopsy. Patients having LP resection during oculoplastics procedures for treatment of ptosis may therefore be able to avoid a separate procedure for limb muscle biopsy. Further study is required to determine the specificity of these findings.
Division of Neurology, University of British Columbia, Vancouver, British Columbia, Canada.
Gerald
G
Pfeffer
Paula J
PJ
Waters
John
J
Maguire
Hilary D
HD
Vallance
V A
VA
Wong
Michelle M
MM
Mezei
D000328:Adult; D000368:Aged; D001706:Biopsy; D045304:Cytochromes c / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000378:metabolism; D005121:Extremities / Q000473:pathology; D005260:Female; D005820:Genetic Testing; D006801:Humans; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009801:Oculomotor Muscles / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D017246:Ophthalmoplegia, Chronic Progressive External / Q000175:diagnosis* / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length / Q000235:genetics
D004272:DNA, Mitochondrial; D045304:Cytochromes c; D003576:Electron Transport Complex IV