[1] Univ Penn, Dept Neurol, Sch Med, Philadelphia, PA 19104 USA
[2] Univ Penn, Dept Pharmacol, Sch Med, Philadelphia, PA 19104 USA
[3] David Mahoney Inst Neurol Sci, Philadelphia, PA USA
[4] Penn Epilepsy Ctr, Philadelphia, PA USA
[5] Harvard Univ, Sch Med, Dept Neurol, Massachusetts Gen Hosp,MGH Epilepsy Serv, Boston, MA 02115 USA