Introduction

Lafora disease is an uncommon inherited disease that causes the late onset of progressive myoclonic epilepsy in human and animals. Polyglucosan body (also known as Lafora body) formation in the nervous tissues is considered to be the diagnostic criteria for this disease.

Objectives

Histopathological and immunohistochemical features of polyglucosan bodies accumulated in the neural and extraneural tissues of a male miniature wire-haired dachshund with history of blindness and intermittent epilepsy, are described.

Methods

Paraffin embedded tissue sections including the brain, spinal cord and extraneural tissues such as eye, liver and skeletal muscle were routinely stained with hematoxylin and eosin. The periodic acid-Schiff and alcian blue stains were performed in order to demonstrate types of the inclusion bodies deposited. Immunohistochemical stains for EPM2A/laforin, ubiquitin, neurofilament triplet protein and GFAP were also done.

Results

Histological findings revealed the accumulation of abundant PAS-positive inclusion bodies within the perikarya, neurites, neuropils and other extraneural tissues. The inclusions were immunopositive for EPM2A/laforin, ubiquitin and neurofilament triple protein, indicating that the structures of the inclusion bodies comprise not only polysaccharide only but also abundant misfolded proteins.

Conclusions

According to the presence of Lafora-like polyglucosan bodies together with laforin, ubiquitin and neurofilament triplet protein in the nervous tissues and the results of genetic examination, this case is closely related to the characteristic of Lafora disease in human.