Alumina Cream-Induced Focal Motor Epilepsy in Cat. Part 5. Excision and Transplant of the Epileptogenic Granuloma

Abstract

The role of alumina cream (AC) epileptic granulomas in producing clinical convulsions and EEG spikes was evaluated by excising and transplanting such granulomas from donors to recipient cats. In donors, granulomas were produced by single microinjections of AC into the right motor cortex and were subsequently excised during latent premature (P), mature (M), convulsive and remission stages. The excised granulomas from donors were homogenized and injected into the homologous cortices of the recipient cats. The epileptogenic effect of the AC granuloma transplant in the recipients and the antiepileptogenic effect of the AC granuloma excision in the donors were evaluated by the presence or absence of clinical convulsions and the maximal EEG spike density at the right motor cortex (MSD) after lesion excision and transplant. A correlation between MSD (spikes/10 min) of donors and recipients and the aluminum content (.mu.g/ml) in granuloma and perilesional cortex of control epileptic cats (neither excised nor transplanted) was established during latent P, M, convulsive and remission stages. The epileptogenic effect of AC granulomas transplanted into recipients was significantly larger when they were excised from donors in latent P and M than in convulsive, and in convulsive than in remission. The antiepileptogenic effect of AC granuloma excision in donors was significantly larger in latent P than in latent M and convulsive, and in convulsive than in remission. The aluminum content of AC granuloma and perilesional and contralateral cortices in controls was significantly larger in latent P and M than in convulsive and in convulsive than in remission. There was a significant positive correlation between MSD of all recipients and the aluminum content in perilesional cortex of control epileptic cats (r = 0.719, P < 0.001). There was a negative correlation btween MSD of latent P, convulsive and remission donors and the aluminum content in perilesional cortex of control epileptic cats (r = 0.650, P < 0.01). The antiepileptogenic effect of AC granuloma excision in donors during the latent M stage was not larger than in the convulsive stage. MSD of these donors did not correlate with the aluminum content of granulomas in epileptic controls.