A 10-month-old, male, pony foal was examined because of stiff gait, marked contractures of the distal portion of the limbs, flexion deformities of the hooves, and moderate hypotonia that had been present from birth.
The foal had increased creatine kinase (282 U/liter; reference interval 10-135 U/liter), lactate dehydrogenase (1,188 U/liter; reference interval 150-450 U/liter), and aspartate transaminase (377 U/liter; reference interval <290 U/liter) activities, suggesting muscle disease.
Muscle biopsy was performed.
In cytochrome oxidase-, succinate dehydrogenase-, and reduced nicotinamide adenine dinucleotide tetrazolium reductase-reacted sections, the dominant morphologic feature was the absence of oxidative enzyme activity in the cores.
By use of immunohistochemical technique with a monoclonal antibody against desmin, the cores were clearly delineated and a desmin network was present within the cores.
Ultrastructurally, the core areas were characterized by preserved sarcomeres with irregular Z-lines, with some streaming or zigzag appearance and abnormal sarcoplasmic reticulum profiles and T-tubules.
Lack of mitochrondria within central cores was observed. Diagnosis of myopathy with central cores was made.
Source: Paciello O, Pasolini MP, Navas L, Russo V, Papparella S. (2006): Myopathy with central cores in a foal. In: Vet Pathol. 2006 Jul;43(4):579-83.
|
