3. Muscimol infusion - Into the seizure focus, patients will be given two infusions-one of saline (salt water) alone and one of muscimol diluted in saline. Each infusion will be given over a period of one-half to 5 1/2 days, infused at the rate of 0.1 ml (1/50th of a teaspoon) per hour. During the infusions video-EEG recordings will continue and patients will be interviewed and examined as described in #2 above).