Journal: Brain Stimulation, 12(2)-412(2019)
Authors: L Bokovza, U Alyagon, H Shalev, A Zangen
Attention deficit hyperactivity disorder (ADHD) is a highly prevalent neuropsychiatric disorder. The right prefrontal cortex (rPFC) which plays a central role in regulation of behavior and attention is one of the primary areas showing deficits in ADHD. Transcranial magnetic stimulation (TMS) can induce alterations in neural excitability and neural networks. The authors recent study has shown lasting electrophysiological alterations and clinical improvement following 15 daily high-frequency (HF) deep TMS (dTMS) sessions directed to the rPFC. This improvement was highly correlated with an electrophysiological marker measured during the first treatment session. To validate this finding the authors now pre-screen participants and offer HF dTMS treatments only to those who are likely to benefit from it.Patients who are not compatible for HF dTMS may benefit from an alternative treatment strategy of paired associative stimulation (PAS), which aims to balance interhemispheric activity. PAS was recently shown in their lab to modulate both behavior and interhemispheric connectivity in healthy subjects.
Developing individualized brain stimulation treatment for ADHD based on subject’s EEG and TMS-EEG measures.
Participants undergo a preliminary EEG measurement before and during the first HF dTMS session, according to which they are assigned to 15 treatments of either HF dTMS or PAS. Evaluation of changes in ADHD symptoms is performed by standard questionnaires, cognitive tasks and EEGrecordings.
While unblinding for interim analysis of clinical efficacy will soon be performed, independent electrophysiological analysis before and after 15 sessions indicates that active, but not sham, PAS treatment causes significant reduction in mean power of theta band during rest EEG (N=8 for each group). HF dTMS increases laterality of theta and gamma bands, and reverses laterality of alpha activity, during rest EEG (N=9).
Multiple dTMSsessions appear to induce lasting alterations in resting state activity in the brain.