Lafora's disease in an epileptic Basset hound

Abstract

A 6-year-old Basset hound developed a progressive central nervous system disease culminating in epileptic seizures. Histologically, Lafora bodies were found in neurones of the middle and deeper cerebral cortex and midbrain, in Purkinje cells and their processes, and in glial cells of the molecular layer of the cerebellum. Many were also observed free in the neuropil. The ultrastructural and histochemical characteristics of the bodies were similar to those described in previous human and canine cases of Lafora's disease.

Polyglucosan Storage Disease in a Dog Resembling Lafora's Disease

“…These intracytoplasmic filamentous masses are not membrane bound and, if large, tend to displace the nucleus and cytoplasmic organelles to the periphery of the cell. 8,9,12,23 Methods for the antemortem diagnosis of Lafora's disease in domestic animals are not well described. Even though cerebral biopsy in domestic animals is theoretically possible, the difficulties in performing this procedure limit its use in a clinical setting.…”

“…Previous reports have described this condition in association with clinical signs in Basset Hounds, [8][9][10] a Miniature Poodle, 8 a Standard Poodle, 7 a Pointer, 11 a Corgi, 12 and Beagle Dogs, 13,14 as well as in a Maine Coon cat. 15 A recent diagnosis of this condition was also made in a group of Miniature Wirehaired Dachshunds in the United Kingdom.…”

“…24 Even though skeletal muscle biopsies led to a likely diagnosis of Lafora's disease in these dogs, uncertainty exists as to whether this diagnosis can be reliably and consistently established on this basis, since several domestic animal cases have been described in which typical Lafora bodies were identified in CNS tissue but were absent in muscle tissues. 9,12,15 False-negative muscle biopsies have also been described with Lafora's disease in humans. 1 It is not certain, however, whether PAS staining or electron microscopy was used for muscle sections in the above cases, since the polyglucosan bodies could theoretically have been present but easily missed if only HE stains were examined.…”

“…Further, they stain positive with methenamine silver, weakly metachromatic with toluidine blue, and negative with Sudan Black and acid-fast stains. 8,9,14,15 On electron microscopy, the Lafora bodies typically present as rounded, oval, or elongated bodies composed of short filaments, electron-dense granules, and electron-dense amorphous material. These components are usually homogeneously distributed, but in some cases, the amorphous material forms an electron-dense core.…”

“…2,10 Until recently, the diagnosis of Lafora's disease in domestic animals primarily relied on a postmortem and lightand electron-microscopic examination of central nervous system (CNS) tissue, in which typical intraneuronal polyglucosan bodies (Lafora bodies) were identified within neuronal perikarya and neuronal processes throughout the brain and spinal cord. 8,9,[11][12][13][14][15] On light microscopy, these intraneuronal polyglucosan bodies typically are round to oval and diastase resistant; they also stain basophilic on HE stains and stain intensely PAS positive. Further, they stain positive with methenamine silver, weakly metachromatic with toluidine blue, and negative with Sudan Black and acid-fast stains.…”