title: Low and High Frequency Hippocampal Stimulation for Drug-Resistant Mesial Temporal Lobe Epilepsy.
abstract: OBJECTIVE
  Electrical stimulation of the hippocampus offers the possibility to treat patients with mesial temporal lobe epilepsy (MTLE) who are not surgical candidates. We report long-term follow-up results in five patients receiving low or high frequency hippocampal stimulation for drug-resistant MTLE.
  
  
  METHODS
  The patients underwent stereotactic implantation of quadripolar stimulating electrodes in the hippocampus. Two of the patients received unilateral electrode implantation, while the other three received bilateral implantation. Stimulation of the hippocampal electrodes was turned ON immediately after the implantation of an implantable pulse generator, with initial stimulation parameters: 1 V, 90-150 μs, 5 or 145 Hz. The frequency of seizures was monitored and compared with preimplantation baseline data.
  
  
  RESULTS
  Two men and three women, aged 27-61 years were studied, with a mean follow-up period of 38.4 months (range, 30-42 months). The baseline seizure frequency was 2.0-15.3/month. The five patients had an average 45% (range 22-72%) reduction in the frequency of seizures after hippocampal stimulation over the study period. Low frequency hippocampal stimulation decreased the frequency of seizures in two patients (by 54% and 72%, respectively). No implantation- or stimulation-related side effects were reported.
  
  
  CONCLUSIONS
  Electrical stimulation of the hippocampus is a minimally invasive and reversible method that can improve seizure outcomes in patients with drug-resistant MTLE. The optimal frequency of stimulation varied from patient to patient and therefore required individual setting. These experimental results warrant further controlled studies with a large patient population to evaluate the long-term effect of hippocampal stimulation with different stimulation parameters.
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Siew-Na
authors.initials: SN
authors.lastname: Lim
authors.affiliation: Department of Neurosurgery, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Ching-Yi
authors.initials: CY
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Shih-Tseng
authors.initials: ST
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Po-Hsun
authors.initials: PH
authors.lastname: Tu
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Bao-Luen
authors.initials: BL
authors.lastname: Chang
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Chih-Hong
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Mei-Yun
authors.initials: MY
authors.lastname: Cheng
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Chun-Wei
authors.initials: CW
authors.lastname: Chang
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Wei-En Johnny
authors.initials: WE
authors.lastname: Tseng
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Hsiang-Yao
authors.initials: HY
authors.lastname: Hsieh
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Hsing-I
authors.initials: HI
authors.lastname: Chiang
authors.affiliation: Department of Neurology, Section of Epilepsy, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Tony
authors.initials: T
authors.lastname: Wu
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D001703:Biophysics; D046690:Deep Brain Stimulation / Q000379:methods*; D000069279:Drug Resistant Epilepsy / Q000628:therapy; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000628:therapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome; D014741:Video Recording
chemical_list: D000927:Anticonvulsants; D019788:Fluorodeoxyglucose F18
keywords: deep brain stimulation; epilepsy; high frequency electrical stimulation; low frequency electrical stimulation; outcomes