Thiamine deficiency encephalopathy with concurrent myocardial degeneration and polyradiculoneuropathy in a cat.

Hyaline degeneration, myofiber fragmentation, and mineralization were present in the left ventricle of an aged, female Siamese cat with both clinical and histopathological evidence suggestive of a thiamine deficiency encephalopathy. Both a thiamine related biochemical lesion and neurogenic myocardial degeneration ("Brain-Heart" Syndrome) may have contributed to the development of the heart lesions. A concurrent lumbar polyradiculoneuropathy, characterized by ballooning myelin sheaths with axonal degeneration, was considered an incidental, age-related finding.