| Disorders of consciousness(DOC)are the most severe impairment in patients with brain injury and has a higher incidence in recent years due to improved critical care.Recovery of consciousness is the primary task for DOC patients.Arousal therapy includes drug and surgical therapy,musical therapy,Peripheral and central stimulation,and so on.Nevertheless,there are still no highly effective treatments that can improve consciousness in all DOC patients.Repetitive transcranial magnetic stimulation(rTMS),a non-invasive brain stimulation technique,is widely used in neurological dysfunctions and has been considered a great promising in treating DOC patients.However,it is still no a clinical study with high quality to verify the promising efficacy.Therefore,this study focuses on the therapeutic efficacy of rTMS in DOC patients.A retrospective analysis was made to know the present situation of DOC patients via recruiting 384 patients with brain injury,including 188 cases(50.0%)with cerebral hemorrhage,108 cases(28.1%)with cerebral infarction,75 cases(19.5%)with traumatic brain injury,and 13 cases(3.4%)with ischemic-hypoxic encephalopathy.Among 384 patients with brain injury,there were 143 patients with DOC,and the incidence of DOC was 37.2%.Among 143 patients with DOC,there were 78 cases(54.5%)with cerebral hemorrhage,12 cases(8.4%)with cerebral infarction,43 cases(30.1%)with traumatic brain injury,and 10 cases(7.0%)with hypoxic-ischemic encephalopathy.The incidence of DOC was 41.5%(78/188)in patients with cerebral hemorrhage,11.1%(12/108)in patients with cerebral infarction,57.3%(43/75)in patients with traumatic brain injury,and 76.9%(10/13)in patients with hypoxic-ischemic encephalopathy.The analysis of DOC and non-DOC patients showed that the length of stay and the medical cost were both significantly higher in DOC patients than in non-DOC patients,which suggested that DOC significantly increases the burden in patients.The lack of effective treatment is the major problem for DOC patients.A randomized,double-blinded,and controlled study was performed in forty patients with DOC to explore the therapeutic efficacy in improving the consciousness of DOC patients.The consciousness was evaluated using the Coma Recovery Scale-revised(CRS)before and after treatment.The outcome of DOC patients at discharge was assessed.The results showed that the CRS-R scores were significantly higher in the trial group compared to the control group,which indicated that rTMS improved the level of consciousness in DOC patients.Further analysis showed that not all DOC patients could obtain improved consciousness.The results also found no significant difference in outcome at discharge between the trial and control groups.Based on the previous results,we hypothesized that although rTMS treatment could improve the level of consciousness in DOC patients,it might not be applicable to all DOC patients.25 DOC patients were recruited again and treated by rTMS for a total of 20 sessions over four weeks,and the consciousness was assessed using CRS-R before and after treatment.Resting EEG signals were evaluated in all DOC patients before and after the first rTMS intervention.A 3-point increase in CRS-R before and after treatment was defined as a responder,otherwise a non-responder.The results revealed that 10 of 25 patients were responders and 15 were non-responders.EEG data showed significantly more parietal alpha power in responders than in non-responders,and a single session of rTMS significantly reduced delta power at the stimulation site(frontal lobe)in responders,while there was no significant change in non-responders.Meanwhile,this study suggests that the alpha(parietal lobe)/delta(frontal lobe)ratio can be used to identify responders.In summary,there is a high DOC incidence in patients with brain injury.The lack of specific wakefulness-promoting treatments is the main difficulty in treating DOC patients.rTMS can improve the level of consciousness in DOC patients and be an effective method in treating the DOC.However,it seems not applicable to all DOC patients.Therefore,we speculate that there are responders and non-responders in DOC regarding rTMS treatment.Although rTMS have therapeutic efficacy,an emphasis of rTMS application in DOC patients should identify the responders in DOC patients in advance.This study proposes a prediction method:the ratio of alpha(parietal)/delta(frontal),which can be used to identify responders. |
