What is new in research on TMS?
In this Research Roundup, we explore new studies on transcranial magnetic stimulation (TMS) and other non-invasive brain stimulation (NIBS) techniques on major depressive disorder (MDD), attention-deficit/hyperactivity disorder (ADHD), and more psychiatric disorders and symptoms.
Can Baseline Pupillary Responses Predict Success of rTMS in MDD Treatment?
This study investigated the relationship between pupillary light reflex (PLR) measurements and clinical outcomes in the context of repetitive transcranial magnetic stimulation (rTMS) treatment for major depressive disorder (MDD). Researchers found a significant positive correlation between the extent of pupillary constriction before treatment and the degree of symptom improvement. This suggests that greater pupillary constriction amplitude at baseline is associated with better treatment outcomes, indicating that PLR measurements may serve as useful biomarkers for predicting the success of rTMS treatment for MDD.
“The current results indicate that PLR holds significant promise as a biomarker for outcomes of rTMS treatment,” the investigators concluded. “These findings emphasize the importance of understanding the [autonomic nervous system] (ANS) in the treatment of depression, including whether normalized ANS function is a prerequisite to (or product of) successful rTMS treatment of MDD.”
Citrenbaum C, Corlier J, Ngo D, et al. Pretreatment pupillary reactivity is associated with outcome of repetitive transcranial magnetic stimulation (rTMS) treatment of major depressive disorder (MDD). J Affect Disord. 2023;339:412-417.
rTMS Shows Promise in Improving Cognitive Function in ADHD
This meta-analysis investigated the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) for cognitive functions in individuals with attention-deficit/hyperactivity disorder (ADHD). Its findings suggest that rTMS treatment can lead to significant improvements in sustained attention and processing speed among individuals with ADHD. However, there was no significant difference in therapeutic efficacy between rTMS targeting the right prefrontal cortex (rPFC) and other brain regions, and the results regarding memory and executive function were less conclusive.
“The limitation of available data warrants further studies to elucidate the correlation between the selection of brain regions for rTMS targeting and its therapeutic efficacy for different sub-categories of cognitive functions,” the investigators concluded.
Chen YH, Liang SC, Sun CK, et al. A meta-analysis on the therapeutic efficacy of repetitive transcranial magnetic stimulation for cognitive functions in attention-deficit/hyperactivity disorders. BMC Psychiatry. 2023;23(1):756.
Exploring the Effects of Non-Invasive Brain Stimulation on Consciousness in Patients With Brain Injury
This study was a systematic review and meta-analysis that examined the effects of non-invasive brain stimulation (NIBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) on disorders of consciousness (DOC) in patients with brain injury. The study results showed that NIBS techniques can improve the level of consciousness in these patients, but further research is needed to determine the optimal parameters and protocols for these interventions.
“NIBS has a significant positive effect in enhancing the symptoms of DOC,” the investigators concluded. “Nevertheless, it is imperative for further investigations comprising high-quality research designs and larger sample sizes in order to comprehensively elucidate the effects of NIBS techniques on diverse targets of stimulation within the population of individuals suffering from DOC.”
Hu Y, Hu L, Wang Y, et al. The effects of non-invasive brain stimulation on disorder of consciousness in patients with brain injury: a systematic review and meta-analysis of randomized controlled trial [published online ahead of print, 2023 Oct 14]. Brain Res. 2023;1822:148633.
Note: Assistance from ChatGPT and ChatPDF was used in the preparation of this research roundup.
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