Repetitive transcranial magnetic stimulation improves consciousness in some patients with disorders of consciousness

Abstract

Objective To investigate the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) in patients with disorders of consciousness. Design and Setting We performed a randomized, double-blinded, sham-controlled trial. Participants Patients (N = 40) with disorders of consciousness. Interventions Forty patients with disorders of consciousness (time since onset of the disorder 49.0 ± 24.6 days) were enrolled and randomized to groups receiving either active-rTMS or sham-rTMS. The active-TMS protocol had a frequency of 20 Hz, was delivered over the left dorsolateral prefrontal cortex and had a 100% rest motor threshold. The sham-rTMS protocol was the same as the active protocol without magnetic stimulation over the cortex. Main Outcome Measures Consciousness was evaluated by the Coma Recovery Scale-Revised (CRS-R) before and after the four-week intervention. The ratio of patients that awakened from disorders of consciousness was followed up at discharge. Results Before rTMS sessions, there were no significant differences in consciousness scores between groups. Compared to sham-rTMS (6.25 ± 1.29), patients with disorders of consciousness treated by active rTMS showed strikingly improved consciousness (8.45 ± 3.55). In-depth analysis revealed that only some patients showed obvious increases in consciousness scores induced by active rTMS. Furthermore, rTMS did not significantly enhance the awakening ratio. Conclusions rTMS showed therapeutic efficacy for improving consciousness in some, but not all, patients with disorders of consciousness. It is essential to discern the potential patients whose consciousness can be improved by rTMS.

Effectiveness on level of consciousness of non-invasive neuromodulation therapy in patients with disorders of consciousness: a systematic review and meta-analysis

“…Results from assessment of bias using revised Cochrane risk-of-bias tool for parallel and cross-over studies were presented in Figures 2 , 3 . Only three studies were assessed as “low risks” (Peri et al, 2001 ; Chen et al, 2022 ; Fan et al, 2022 ). In addition, the majority of included studies ( n = 7) were assessed as “some concerns” because of indistinct illustration of randomization process or other relatively rare reasons (Cooper et al, 1999 ; Huang et al, 2017 ; Thibaut et al, 2017 ; Zhang et al, 2017 ; He et al, 2018 ; Martens et al, 2018 ; Wu et al, 2019 ).…”

An update on noninvasive neuromodulation in the treatment of patients with prolonged disorders of consciousness

“…Similar to the choice of target in the protocol of tDCS, bilateral DLPFC and left M1 were also the most common targets in the TMS protocol. Six papers [39][40][41]44,45,49 reported its use in DLPFC, one session in left DLPFC 41 showed positive results only in the MCS group, and the other five (four in left DLPFC, 40,44,45,49 one in right DLPFC 39 ) all showed positive results in the real rTMS group. Two randomized sham-control trials selected M1 as the target.…”

“…Most of them were about 10 or 20 Hz. In the past 5 years, there were four articles about 10 Hz 39–44 and five articles about 20 Hz 45–49 …”

Repetitive transcranial magnetic stimulation over the posterior parietal cortex improves functional recovery in nonresponsive patients: A crossover, randomized, double-blind, sham-controlled study

“…Most studies selected the intervention target of the left dorsal lateral prefrontal cortex (DLPFC). They believed that stimulating the DLPFC can strengthen thalamocortical and cortico-cortical connections and improve behavioral performance, EEG power spectrum, and estradiol levels, particularly in patients in MCS ( 13 – 20 ). However, according to Integrated Information Theory (IIT), consciousness is connected primarily with the posterior cortical areas ( 21 ), of which the posterior parietal cortex (PPC) has been demonstrated as the most critical consciousness-associative cortical region ( 22 ).…”