Herpes Virus-6 and Epilepsy

Subjects of any race or ethnicity will be included in the study. Any subject who has been diagnosed with medically intractable epilepsy and is eligible for the epilepsy protocol #01-N-0139 will be evaluated for entry into this study. INCLUSION CRITERIA: All patients will have a seizure disorder as documented by EEG and video-EEG. Half of the patients will have radiologically documented mesial temporal sclerosis and the other half will have a brain MRI without mesial temporal sclerosis. The patients can only be on phenytoin, carbamazepine, oxcarbazepine, lamotrigine or levetiracetam, since these anti-epileptic drugs have the least or no effect on the glutamate and GABA levels in the brain. The patients can not take any other medications. Healthy control subjects entering the study must be free of serious disease as determined by a standard physical and neurological examination. The control subjects can not be on any medication. All subjects must be able to give informed consent allowing us to use the cerebrospinal fluid and serum for research. All subjects will have to be able to refrain from chocolate, tea and coffee (low monoamine diet; Wood et al.1979) and alcohol during the one week before the study. Patients must be seizure free for 48 hours prior to the lumbar tap and the MRS. EXCLUSION CRITERIA Subjects will be excluded if: They are under the age of 18 They are female and are pregnant They have a history of medical disorders which can affect the concentration of cerebral metabolites, including diabetes mellitus, renal dysfunction, hepatic dysfunction and electrolyte abnormality They take any medication for the normal control group They take any medication, with the exception of phenytoin, carbamazepine, oxcarbazepine, lamotrigine and levetiracetam for the epilepsy patients They have a history of psychiatric and/or mood disorders They have implanted devices such as pacemakers, medication pumps or defibrillators, or metal in the cranium except for the mouth, intra-cardiac lines, a history of shrapnel injury or any other condition/device that may be contraindicated or prevent the acquisition of MRI They have a coagulopathy that prevents them from having a lumbar puncture performed They have had a seizure 48 hours prior to the MRS and the lumbar tap Subjects who cannot give informed consent allowing us to use the removed fluid for research will also be excluded.