Transcranial Direct Current Stimulation and Cognitive Remediation Therapy for Interictal Dysfunction in Epilepsy

Transcranial Direct Current Stimulation and Cognitive Remediation Therapy for Interictal Dysfunction in Epilepsy

The purpose of this study is to investigate whether tDCS enhances the effect of cognitive remediation therapy on cognition and functional outcome in patients with epilepsy. There has been evidence that working memory performance is enhanced in healthy subjects. Acute tDCS studies have found improvements in working memory performance in subjects with other neurological diseases. To date, there have been no published studies examining whether can enhance learning during multi-session cognitive remediation over 2 weeks in subjects with epilepsy. This study could have potential application as a non-invasive clinical intervention for interictal dysfunction in epilepsy.

Epilepsy is a chronic neurological disorder affecting 50 million people worldwide. Patients suffer not only from recurring seizures, but also from cognitive deficits despite adequate treatment control. Cognitive remediation therapy (CRT) is a therapeutic intervention that has recently shown promise in improving cognitive impairment in many neuropsychological disorders. Transcranial direct current stimulation (tDCS) is a non-invasive method that modulates cortical excitability. It works by applying weak electrical currents to the scalp that induce acute modifications of neuronal membrane potentials, producing long-lasting changes in the bioelectric activity of underlying brain tissue. It is postulated that tDCS enhances benefit gained through cognitive remediation therapy. These interventions have yet to be combined with each other for the treatment of interictal dysfunction in patients with epilepsy. The goal of the study is to investigate whether the introduction of tDCS in addition to CRT is effective in the treatment of cognitive impairment in patients suffering from epilepsy.

Inclusion Criteria:

• Age 18-64
• Epilepsy diagnosis confirmed by the UMN Comprehensive Epilepsy Center
• Complete seizure logs of the type in standard clinic use at the UMN Comprehensive Epilepsy Center for at least 12 weeks prior to study entry
• Stable CNS medications for the 2 weeks prior to the initiation visit and expected to continue with current medication doses for the two weeks of the intervention
• No diagnosis of mental retardation (IQ not less than 70) or pervasive developmental disorder
• At least one subtest of learning and memory less than --1.5 SD
• Sufficient spoken English so as to be able to comprehend testing procedures
• Competent and willing to provide consent

Exclusion Criteria:

• Occurrence of generalized convulsive status epilepticus or of complex partial status epilepticus within 1 year prior to study entry
• Occurrence of more than 1 generalized tonic-clonic (GTC) seizure per month, or more than 4 complex partial (CP) seizures per week, as reported in the subject's seizure logs for 12 weeks prior to study entry
• Occurrence of GTC seizure within 48 hours before testing
• Any anti-epileptic medication changes or hospitalizations in the previous 4 weeks
• Additional neurologic disorder other epilepsy and cognitive dysfunctions
• History of metallic cranial plates, screws, or implanted devices
• History of craniotomy