Efficacy of 128-channel EEG Combined With BESA Dipole Localization and Intervention on Brain Waves for Epilepsy

Background: The prevalence of epilepsy is about 0.5% to 1% worldwide, with high disability and mortality rate. The 128-channel electroencephalograph (EEG), combined with Brain Electrical Source Analysis (BESA) dipole localization method, is able to provide more specific information about the brain activity and find out the epileptogenic focus. Based on this novel EEG recording method, cathode transcranial direct current stimulation (tDCS) targeting the epileptogenic focus can be used to decrease the excitability of the cortex, thus reducing the frequency of seizures.

Methods: A single-center double-blinded randomized controlled and open-label extension trial will be carried out to study the efficacy of 128-channel electroencephalograph combined with BESA dipole localization method and Intervention on brain waves for epilepsy. Adult patients aged 18 to 65 years old with epilepsy will be recruited. The study contains two stages. At the first randomized controlled stage, patients will be randomly assigned to experimental and control group with a 1:1 sqrt allocation and undergo five daily sessions of brain-wave intervention by cathode tDCS （20min, 1mA） targeting the epileptogenic focus, which is confirmed by 128-channel EEG and BESA dipole localization method. Active intervention will be carried out for the experimental group, and sham intervention ( the stimulator will be turned off after 5s) for the control group. The frequency of seizures, the number of epileptiform discharges, the diffusion tensor imaging (DTI) of magnetic resonance imaging (MRI), the cognitive function, the psychology and the life quality will be measured before (baseline), 1 hour, 4 weeks and 12 weeks after the last intervention to evaluate the changes after intervention. At the second open-label extension stage, all the patients will undergo five daily sessions of active intervention (20min, 1mA) and be followed up for 12 weeks similar to the first stage.

Inclusion criteria

• Diagnosed with epilepsy at least 1 year according to the 2010 International League Against Epilepsy (ILAE) criteria.
• Aged 18 to 65 years old.
• The seizure is not well-controlled by antiepileptic drugs, the patient cannot tolerant the side effect of antiepileptic drugs, or the patient is not satisfied with the curative effect.
• The dose of antiepileptic drugs must be stable in the last 4 weeks.
• The patient or his/her family member is able to recording the frequency of seizures and complete the trial.

Exclusion criteria

• History of status epilepticus in the last 12 weeks according to the definition by Neurocritical Care Society (NCS) 2012.
• History of transcranial direct current stimulation, repetitive transcranial magnetic stimulation, vagus nerve stimulation, trigeminal nerve stimulation or deep brain stimulation. History of pacemaker or other metal equipment implantation.
• History of skull defect, brain tumor, encephalitis, progressive encephalopathy and other progressive diseases of central nervous system.
• History of severe cardiac, hepatic, renal, hematologic diseases, or other progressive and systemic diseases, or during pregnancy.
• History of major depression and other mental disturbance, color blindness, hearing or language disorder who is not able to complete the trial.