Focal Motor Seizures

To the Editor.—  In their recent article in the Archives (33:536, 1976), Collins et al report that the uptake of carbon 14-labeled 2-deoxyglucose is increased in the thalamus during severe focal seizures with or without bilateral spread; they attribute the changes in their autoradiographs to increased neuronal metabolism associated with seizure spread. A number of years ago, my associates and I¹ reported a study of the influence of 25% CO₂ on the uptake of sulfur 35-labeled sulfate by brain and demonstrated autoradiographic changes that are very similar in appearance to those of Collins and co-workers, that is, a patchy increase in radioactivity in the thalamus of some animals. We referred in that article to still earlier studies by Lee and Olszewski² and Rozdilsky and Olszewski³ who demonstrated a similar pattern in animals subjected to electroshock in studies using radioiodine-labeled albumin. We concluded that the changes in both studies were