Can patients perform volitional motor acts at the start of a seizure?

A seizure warning device might allow some individuals with partial seizures to protect themselves against consequences of seizures, but a prerequisite is the ability to take volitional action in response to a warning. The aut hors reviewed consecutive seizures in their epilepsy monitoring unit to det ermine whether patients could squeeze an event bulb, as instructed, at the start of their seizure. Only complex partial seizures with EEG changes and with the patient on camera were analyzed. Data were obtained from 77 patien ts, 42 with scalp monitoring and 35 with depth electrodes. Forty-seven perc ent had a left-hemisphere focus, 42% a right-hemisphere focus, and 11% mult ifocal seizures. The seizure focus was temporal in 68%. A magnetic resonanc e imaging consistent with mesial temporal sclerosis was seen in 29% of pati ents. Overall, 44% of the patients made at least one attempt to reach for t he event bulb at the start of their seizures. Among the 72% of patients who gave a history of auras, 53% were able to press the event bulb compared to 20% with no history of auras (P = 0.016). EEG changes occurred a mean of 2 .9 +/- 30.5 seconds after reaching for the bulb for scalp-recorded seizures (n = 20), and 16.2 +/- 13.7 seconds before behavior for depth-recorded sei zures (n = 14, difference significant at P = 0.02). Neither seizure focus n or seizure laterality influenced the ability to press the event bulb. The a uthors conclude that nearly half of individuals with complex partial seizur es can take volitional motor action at the start of their seizure. A method to enhance the intensity and timeliness of a seizure warning would not be wasted.