DISCUSSION
impaired consciousness, head injury, hypoxia, consciousness disturbance, brain injury, disorders of consciousness, necrosis, cerebral ischemia
HYPOXIA, BRAIN DEATH, CEREBRAL ISCHEMIA, SECONDARY, NECROSIS, CORTEX
In this study, the experimental group underwent 20 Hz rTMS to stimulate the M1 brain area of VS patients. It was found that the clinical awakening effect was more notable than that of the control group and the placebo group. It was mainly manifested in two clinical indicators, namely, the GCS and CRS‐R two clinical scale evaluation indicators. After treatment, the GCS and CRS‐R scores of the experimental group were significantly improved except for one case of brain death that had a score of 0. In addition, two other neuroelectrophysiological indicators were used, namely, EEG and SSEP measures.The occurrence of consciousness disturbance after head injury is related to ischemia‐hypoxic necrosis of brain tissue. This is because cerebral ischemia and hypoxia will directly cause certain areas of the brain to suspend work—for instance the cerebral cortex is not able to effectively activate—and the brain network foundation related to consciousness is in a state of imbalance. It is generally believed that cognition and awakening are correlate with consciousness. Hinter‐buchner refers to these two as the content of consciousness and the switching system. The content of consciousness refers to the high‐level activities of the cerebral cortex, including behavioral responses such as memory, thinking, orientation, motor, speech, and audiovisual activity. The mechanisms governing consciousness can activate the cerebral cortex, maintain excitement, and keep the body in an awake state. Therefore, effective activation of the cerebral cortex and the regulation of the brain–brain functional network are essential for the arousal of disorders of consciousness. High‐frequency rTMS acts on the cerebral hemisphere of the affected side and directly improves the excitability of the cerebral hemisphere (Emara et al., The M1 area is the high‐level nerve center that controls body movements. It plays a very important role in the planned movements of the body and controls autonomous movements. The M1 area receives and processes peripheral sensory information while outputting the information to the basal ganglia. Nerve information is processed, integrated, and conducted in the cortex‐basal ganglia‐thalamus‐cortex neural circuit, which affects the voluntary and autonomous movement of the body. The execution and adjustment of the system are of great significance. The working principle of rTMS is to use a time‐varying magnetic field to generate an induced magnetic field that induces secondary currents in nearby nerve tissues. The latter activates the cerebral cortex, changes the related physiological processes of the brain tissue, and realizes the positioning of the cerebral cortex function. At the same time, it can also adjust the excitability of local brain tissues, improve local brain hemorheology and cortical metabolism, affect the release and transmission of neurotransmitters in the brain, and promote the repair of damaged brain cells, thereby leading to clinical awakening (Giacino & Trott, Recent research results also support our results. For example, Maas et al. (In addition, there are some opinions that rTMS changes cortical metabolism and cerebral blood flow by changing the excitability of the local cerebral cortex, affecting neurotransmitters and their transmission in the brain, increasing the reversibility of damaged cells, and promoting the recovery of brain function (Potapov et al., In summary, rTMS stimulates the M1 area and is effective for improving the clinical consciousness of patients with impaired consciousness. The possible mechanism includes changes in cerebral blood flow speed and neuroelectrophysiological changes by stimulating the cerebral cortex, thereby improving the activity of brain cells. Therefore, the regulation of nerve excitement, the promotion of dopamine secretion, and the regulation of brain wave resonance promote the recovery of brain injury functions and helps in the recovery of consciousness.