High Definition Transcranial Direct Current Stimulation (HD-tDCS) for Refractory Epilepsy

The Efficacy, Safety and Mechanism of High Definition Transcranial Direct Current Stimulation (HD-tDCS) in the Treatment of Refractory Epilepsy

To observe the clinical effect and safety of transcranial electrical stimulation on patients with refractory epilepsy before and after treatment and analyze its therapeutic mechanism.

All participants underwent a medical evaluation that included physical examination and routine laboratory studies before and after high definition transcranial direct current stimulation (HD-tDCS) treatment.Upon meeting the inclusion criteria and providing informed consent, each participant will complete clinical assessments by a trained investigator and HD-tDCS treatment at Anhui mental health centre.

At least 90 participants were randomized (1:1:1) to receive "bilateral active" ,"Unilateral active" or "Sham" treatment protocol. The left electrical stimulation cathode was placed over CP5 with return electrodes placed at FT7, C1, P03 and P9 . The right electrical stimulation cathode was placed over CP6 with return electrodes placed at FT8, C2, PO4 and P10 .

In the bilateral treatment group, HD-tDCS treatment was placed on the left and right sides of the brain, at least eight hours apart. Twenty 2-mA sessions (ramp-up and ramp-down periods of 30 and 30 seconds, respectively) were applied for 30 minutes,twice a day over 10 consecutive workdays. In the unilateral treatment group, HD-tDCS treatment based on Epileptic discharge is placed on either the left or right side of the brain.Ten 2-mA sessions were applied for 30 minutes,once a day over 10 consecutive workdays.Sham HD-tDCS was delivered using the same protocol and current intensity, but the period of active stimulation was only during the ramp-up and ramp-down periods of 30 and 30 seconds.

Before and after the tDCS treatment, the patients had receiving a battery measure of neuropsychological tests, Magnetic resonance imaging scan in multimodalities, VEEG and Resting motor threshold.

The clinical symptom of participants were followed 4 weeks and 12 weeks after the last treatment.

Inclusion Criteria:

• Clinical diagnosis of refractory epilepsy
• Right-handed and aged 18-50 years old and primary school education or above;
• No major neurological or mental illness, no head injury, alcohol dependence or drug dependence;
• During the experiment, the subjects did not smoke, drink, get sick and take psychotropic drugs, and there were no major life events that caused mood changes.

Exclusion Criteria:

• organic brain injury, neurological diseases or serious physical diseases;
• Have a history of substance abuse and drug dependence, or have used antipsychotic drugs in the past three months, and have serious suicidal tendencies;
• There are contraindications for MRI or EEG or transcranial magnetic stimulation.