Electrical Brain Stimulation to Reduce Epileptic Seizures
Electrical Brain Stimulation to Reduce Epileptic Seizures
OBJECTIVES:

 About 15% of patients suffering from focal epilepsy are refractory to available
 pharmacological treatments. Until now, the only hope for such patients has been the
 development of new pharmaceutical treatments or epilepsy surgery. In case of inoperability,
 different types of invasive brain stimulation such as vagus nerve stimulation or deep brain
 stimulation or non-invasive repetitive TMS have been evaluated to determine their
 anticonvulsive potential. For rTMS, weak and short lasting seizure reduction has been
 reported in different epilepsy syndromes.

 A new, non-invasive stimulation technique, transcranial direct current stimulation (tDCS),
 was useful to modulate cortical excitability in many cortical areas (M1, visual cortex,
 frontal cortex). Cathodal tDCS, with a current of 1 mA, induced long-term depression in
 animal models and reportedly decreased the excitability of both human and animal cerebral
 cortex. In epilepsy patients suffering from a malformation of cortical development, a single
 session of cathodal tDCS helped reduce seizures briefly. The purpose of this protocol is to
 study the effects of repeated applications of tDCS on the excitability of the seizure focus
 in patients with poorly controlled pharmacologically refractory temporal lobe epilepsy.

 STUDY POPULATION:

 We plan to study 56 patients between the ages of 18 and 80 suffering from temporal lobe
 epilepsy.

 DESIGN:

 Subjects will be allocated by blocked randomization to one of two groups (parallel design).
 Group A will receive cathodal tDCS and group B will receive Sham-tDCS on five consecutive
 days. Each subject will participate in 9 sessions (1 baseline visit, 5 intervention visits, 3
 follow-up visits). The effect of the intervention relative to the sham stimulation will be
 evaluated by comparing seizure frequency and neuropsychological tests during the 8 weeks
 before and after the intervention.

 OUTCOME MEASURES:

 Primary outcome measure will be the mean seizure frequency per 4 weeks in the tDCS group as
 compared to the Sham-tDCS group. To analyze the effect of the intervention (tDCS), seizures
 will be evaluated during a 2x4 week baseline period before tDCS and 2x4 weeks after the
 intervention. Using these data we will calculate the percentage change of seizures per 4
 weeks.

 Secondary outcome measures will be the scores of the neuropsychological testing (HVLT-R,
 BVMT-R, CTMT, COWAT) and number of epileptiform discharges in the EEG. Furthermore, th...
OBJECTIVES:

 About 15% of patients suffering from focal epilepsy are refractory to available
 pharmacological treatments. Until now, the only hope for such patients has been the
 development of new pharmaceutical treatments or epilepsy surgery. In case of inoperability,
 different types of invasive brain stimulation such as vagus nerve stimulation or deep brain
 stimulation or non-invasive repetitive TMS have been evaluated to determine their
 anticonvulsive potential. For rTMS, weak and short lasting seizure reduction has been
 reported in different epilepsy syndromes.

 A new, non-invasive stimulation technique, transcranial direct current stimulation (tDCS),
 was useful to modulate cortical excitability in many cortical areas (M1, visual cortex,
 frontal cortex). Cathodal tDCS, with a current of 1 mA, induced long-term depression in
 animal models and reportedly decreased the excitability of both human and animal cerebral
 cortex. In epilepsy patients suffering from a malformation of cortical development, a single
 session of cathodal tDCS applied to various cortical areas including frontal and temporal
 cortex helped reduce seizures briefly. The purpose of this protocol is to study the effects
 of repeated applications of tDCS on the excitability of the seizure focus in patients with
 poorly controlled pharmacologically refractory frontal and/or temporal lobe epilepsy.

 STUDY POPULATION:

 We plan to study 56 patients between the ages of 18 and 80 suffering from frontal and/or
 temporal lobe epilepsy.

 DESIGN:

 Subjects will be allocated by blocked randomization to one of two groups (parallel design).
 Group A will receive cathodal tDCS and group B will receive Sham-tDCS on five consecutive
 days. Each subject will participate in 9 sessions (1 baseline visit, 5 intervention visits, 3
 follow-up visits). The effect of the intervention relative to the sham stimulation will be
 evaluated by comparing seizure frequency and neuropsychological tests during the 8 weeks
 before and after the intervention.

 OUTCOME MEASURES:

 Primary outcome measure will be the mean seizure frequency per 4 weeks in the tCDS group as
 compared to the Sham-tDCS group. To analyze the effect of the intervention (tDCS), seizures
 will be evaluated during a 2x4 week baseline period before tDCS and a 2x4 weeks after the
 intervention. Using these data we will calculate the percentage change of seizures/4 weeks.

 Secondary outcome measures will be the scores of the neuropsychological testing (HVLT-R,
 BVMT-R, CTMT, COWAT) and number of epileptiform discharges in the EEG. Furthermore, the
 patients will answer several questionnaires to evaluate quality of life (QOLIE-31-P), seizure
 severity (SSQ), and mood (BDI). To better understand the mechanisms underlying the proposed
 change of seizure frequency, we will use single- and paired- pulse transcranial magnetic
 stimulation (TMS) to identify corticomotor excitability changes.
-  INCLUSION CRITERIA:

 Patients will be included under the following circumstances:

 1. Age between 18 to 80 years.

 2. Written informed consent is given by the patient.

 3. Epileptogenic focus in the temporal lobe or in the frontal lobe (unilateral or
 bilateral with dominant focus).

 4. Seizures are not completely responsive to medical treatment (8 or more seizures per
 month for at least 3 months) and patients have failed at least two anticonvulsant
 regimens in the past. The implantation of a vagus nerve stimulator will also be
 counted as anticonvulsant regimen.

 5. A stable anticonvulsant regimen (not more than three anticonvulsants) defined as
 unchanged dose or dose modifications lower than 20% in the last month (Blood levels of
 anticonvulsants will be measured at the beginning of the study, prior and after
 intervention, and after the study to assure that the type and dose of medication
 remains constant). For the vagus nerve stimulator, the stimulation parameters will
 have to be unchanged for at least one month.

 6. One antidepressant on a stable dose regimen for at least 1 month will be allowed.

 7. Mini-Mental-Status examination greater than or equal to 23 points.

 8. Commitment to participate in the long-term follow-up (up to 5 months).

 EXCLUSION CRITERIA:

 We will exclude patients if one of the following conditions applies:

 1. A history of any neurological illness other than the epilepsy.

 2. Acute symptomatic seizures (caused by brain tumor, acute stroke, intracranial
 hemorrhage, encephalitis) or psychogenic seizures.

 3. Generalized epilepsy or focal epilepsy with the epileptogenic zone outside the
 temporal lobe.

 4. A history of severe alcohol or drug abuse; psychiatric illness such as severe,
 clinically significant depression (as evaluated by BDI); poor motivational capacity;
 or severe language disturbances, particularly of receptive nature or with serious
 cognitive deficits.

 5. More than moderate uncontrolled medical problems (e.g., cardiovascular disease, active
 cancer or renal disease, any kind of end-stage pulmonary or cardiovascular disease,
 hypo/hyperthyroidism, severe diabetes, peripheral arteriopathy, or a deteriorated
 condition due to age, or other medical conditions as determined by the study
 physician, that would interfere with participation in this study).

 6. Increased intracranial pressure as evaluated by clinical means (presence of
 papilledema in eye ground exam, compressed sulci/ventricle on MRI scan).

 7. Previous implantation of metallic material (e.g., vascular clips, cochlear implant) in
 the cranium (except in the mouth), pacemaker, implanted medication pumps, neural
 stimulators. This does not apply for implantation of a vagus nerve stimulator
 (Cyberonics ® (Registered Trademark) [Registered Trademark] 100, 102 or 102R).

 8. Drug treatment acting primarily on the central nervous system (other than the regular
 anticonvulsant treatment and one antidepressant) that lowers the seizure threshold
 such as antipsychotic drugs (chlorpromazine, clozapine) or tricyclic antidepressants.

 9. Diseased or damaged skin over the face or scalp.

 10. Pregnancy.