S29. rTMS application in disorders of consciousness

Abstract

Introduction There is an unmet need in effective neurorehabilitation methods in chronic disorders of consciousness (DOC). Non-invasive brain stimulation, such as navigated rTMS, is a perspective tool for modulation of the cerebral networks activity in such patients, and resting FMRI, that allows estimating the neural networks activation and interactions, may indicate the target for precise stimulation. Patients with severe brain damage after anoxia or trauma who survived coma, show selective activation of the default mode network (DMN), particularly, gyrus angularis, as the level of consciousness increases. Here, we studied effects of high-frequency navigated rTMS on gyrus angularis as a new approach for the chronic DOC rehabilitation. Methods We included 10 patients with post-anoxic VS (median age 39.3, mean CRS-R score 5.1); 8 patients with post-anoxic MCS (median age 45.8, mean CRS-R score 14.4); 4 patients with traumatic VS (median age 22.3, mean CRS-R 5.8), and 5 traumatic MCS patients (median age 45.8, mean CRS-R 14.4). EEG revealed no seizure-like electric activity. Individual activation assessed by resting fMRI represented DMN activation including left gyrus angularis area in MCS patients, with no activation of DMN in VS patients. Against the background of standard rehabilitation program (motomed letto II-assisted mechanical therapy, massage, passive joints movements) we provided high-frequency rTMS on the gyrus angularis (10 sessions of stimulation with 20 Hz, 2400 stimulus 90% MT). Consciousness level was assessed with CRS-R scale by the same independent rater before and after stimulation course. Results CRS-R score increased in the patients with the residual signs of consciousness behavior (MCS). Median increase in CRS-R score after neurorehabilitation course was 2 points. However, we found no change in clinical assessment in the VS cases. No side effects of the rTMS were observed. Correlation of CRS-r score in permanent disorders of consciousness before and after rTMS course on gyrus angularis. Conclusion The course of the high-frequency TMS with navigation on gyrus angularis is a potentially effective method of rehabilitation in permanent disorders of consciousness. We obtained clinical effect in states of the minimal signs of consciousness, but not in VS. These results are advisable to continue researches in studies of this new protocol’s effectiveness. The study is supported by Russian Science Foundation grant No. 16-15-00274 .