Repetitive transcranial magnetic stimulation improves consciousness disturbance in stroke patients: A quantitative electroencephalography spectral power analysis

How somatosensory evoked potentials improve the diagnosis of the disturbance of consciousness: A retrospective analysis

The interpeak latency is a crucial characteristic of upper limb somatosensory evoked potentials (USEPs). However, the existing research on the correlation between interpeak latency and consciousness disorders is currently limited. We aimed to investigate how USEPs can contribute to the diagnosis of consciousness disorders. A retrospective analysis was conducted on 10 patients who underwent repetitive transcranial magnetic stimulation (rTMS) for consciousness disorders. The interpeak latency N13-N20, Glasgow coma scale (GCS), and Chinese Nanjing persistent vegetative state scale (CNPVSS) were evaluated before and after rTMS treatment, and the linear correlation between N13-N20, GCS, and CNPVSS was analysed. The scores of CNPVSS and GCS significantly increased in the first, second, and third months after rTMS. The N13-N20 was shorter in the second and third months after rTMS compared to before treatment. rTMS was found to shorten the N13-N20 latency, and there was a negative correlation between N13-N20 and the score of consciousness disorders. N13-N20 can serve as an objective index for evaluating consciousness disorders. This research provides potential insights for doctors in diagnosing patients with consciousness disorders.

Effects of 10 Hz repetitive transcranial magnetic stimulation of the right dorsolateral prefrontal cortex in the vegetative state

The aim of the present study was to investigate the effects of 10 Hz repetitive transcranial magnetic stimulation (rTMS) of the right dorsolateral prefrontal cortex (DLPFC) during vegetative state (VS). Between May 2017 and November 2018, 95 patients were treated in the Coma Recovery Department of the Central Hospital of Jinzhou. According to the inclusion and exclusion criteria, a total of 32 patients in VS caused by brain injury were enrolled. The patients were assigned into rTMS and control groups in a non-randomized manner. All patients received JFK Coma Recovery Scale-Revised (CRS-R) scores and underwent motor evoked potential (MEP) latency and central motor conduction time (CMCT) measurement before the first treatment and after 20 days of treatment, which was the end of the study. Following 20 days of treatment, a significant increase was observed in the CRS-R scores of patients in the rTMS group compared with those obtained at pretreatment (P<0.001). An increase in the CRS-R scores of the control group was also observed compared with the pretreatment scores (P=0.035). The change in CRS-R scores (P<0.001) and improved conscious state rate (P=0.0016) were significantly different between the two groups. A significant decrease in MEP (P<0.001) and CMCT (P<0.001) was observed in the rTMS group compared with measurements obtained at pretreatment, whereas no significant decrease was observed in the control group (P=0.693; P=0.070). The changes in MEP (P<0.001) and CMCT (P<0.001) between the two groups were statistically significant. In conclusion, 10 Hz rTMS of the right DLPFC in early disorders of consciousness is feasible and efficient. rTMS treatment could improve patient state of awareness and accelerate patient recovery in VS.

Differentiating Responders and Non-responders to rTMS Treatment for Disorder of Consciousness Using EEG After-Effects

Background: It is controversial whether repetitive transcranial magnetic stimulation (rTMS) has potential benefits in improving the awareness of patients with disorder of consciousness (DOC). We hypothesized that rTMS could improve consciousness only in DOC patients who have measurable brain responses to rTMS.

Objective: In this study, we aimed to investigate the EEG after-effects induced by rTMS in DOC patients and attempted to propose a prediction algorithm to discriminate between DOC patients who would respond to rTMS treatment from those who would not.

Methods: Twenty-five DOC patients were enrolled in this study. Over 4 weeks, each patient received 20 sessions of 20 Hz rTMS that was applied over the left dorsolateral prefrontal cortex (DLPFC). For each patient, resting-state EEG was recorded before and immediately after one session of rTMS to assess the neurophysiologic modification induced by rTMS. The coma recovery scale revised (CRS-R) was used to define responders with improved consciousness.

Results: Of the 25 DOC patients, 10 patients regained improved consciousness and were classified as responders. The responders were characterized by more preserved alpha power and a significant reduction of delta power induced by rTMS. The analysis of receiver operating characteristic (ROC) curves showed that the algorithm calculated from the relative alpha power and the relative delta power had a high accuracy in identifying DOC patients who were responders.

Conclusions: DOC patients who had more preserved alpha power and a significant reduction in the delta band that was induced by rTMS are likely to regain improved consciousness, which provides a tool to identify DOC patients who may benefit in terms of therapeutic consciousness.