Brain damage in the epileptic beagle dog.

Brain lesions associated with seizures in an epilepsy-prone colony of beagle dogs were studied in 68 dogs which died as a result of the disorder. Approximately 48.5% of the dogs had a relatively specific pattern of acute brain damage on microscopic examination. In all affected areas, there was a triad of lesions consisting of perineuronal and perivascular astrocytic swelling, perineuronal basophilic incrustations, and ischemic cell change in neurons. The most common areas of involvement were the cerebral cortex, basal nuclei, claustrum, amygdala, septal nuclei, dorsal thalamic nuclei, isthmus of the pyriform lobe, and hippocampus. The cerebellum was affected only rarely. In addition, intraneuronal inclusions identical to Lafora's bodies found in myoclonus epilepsy of man were detected in thalamic nuclei of six dogs.