HD-tDCS in refractory lateral frontal lobe epilepsy patients.
OBJECTIVE
To evaluate the anticonvulsant effect of the novel high definition transcranial direct current stimulation (HD-tDCS) method on patients with refractory lateral frontal lobe epilepsy. The effects of HD-tDCS on working memory were also examined.


METHODS
10 adult patients with intractable lateral frontal lobe epilepsy were studied. A central cathode electrode was placed on the epileptogenic zone according to LTM, and 20-min sessions of 2mA HD-tDCS were applied for 10 consecutive days. The primary endpoint was to make changes in the epileptiform discharges (EDs) during a 1-h EEG. Moreover, the seizure frequency based on seizure diary and neuropsychiatric parameters was evaluated.


RESULTS
All patients tolerated HD-tDCS stimulation course without any adverse reaction. The frequency of EDs increased immediately and one month after the stimulation course by an average of 6.4% and 1.2%, respectively. However, these changes in the EDs frequency were not statistically significant (p-value >0.05). The mean seizure frequency changes showed decrement by an average of 17.9% immediately, and increment by an average of 38.1% one month after the HD-tDCS. These changes were not significant statistically (p-value >0.05). One patient experienced exacerbation of seizures during the stimulations hence dropped out of the study. Attention and working memory improved significantly immediately and one month after the HD-tDCS in all patients.


CONCLUSIONS
Changes of EDs and mean seizure frequency caused by HD-tDCS were not statistically significant for the whole group; however, this method could improve the patients' working memory scores.
Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Sina Hospital, Tehran University of Medical Science, Tehran, Iran. Electronic address: ahmadik@sina.tums.ac.ir.
Sanaz Ahmadi
SA
Karvigh
Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Sina Hospital, Tehran University of Medical Science, Tehran, Iran. Electronic address: Motamedi@tums.ac.ir.
Mahmoud
M
Motamedi
Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Sina Hospital, Tehran University of Medical Science, Tehran, Iran. Electronic address: mahsaarzani@gmail.com.
Mahsa
M
Arzani
Department of Psychology, Faculty of Education and Psychology, Ferdowsi University of Mashhad, Mashhad, Iran. Electronic address: arman_roshan13@yahoo.com.
Javad Hasan Nia
JH
Roshan
D000328:Adult; D000069279:Drug Resistant Epilepsy / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D004569:Electroencephalography; D017034:Epilepsy, Frontal Lobe / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008499:Medical Records; D008570:Memory, Short-Term; D009483:Neuropsychological Tests; D065908:Transcranial Direct Current Stimulation / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult
HD-tDCS; Intractable epilepsy; Lateral frontal lobe epilepsy; Working memory