| Background and ObjectiveTraumatic brain injury is the leading cause of death and disability in today's society, the rate of neurological dysfunction after mild TBI,moderate TBI and severe TBI is 10%,60% and 100%.The normal neurological dysfunction includes mental-psychological disorders, motor disturbance, neurological deficits, cognitive disorder and conscious disturbance. They seriously affecting the quality of our life and the ability to participate in social activities. So the rehabilitation treatment after traumatic brain injury should be highly emphasized. Traditional rehabilitation therapy such as drugs, hyperbaric oxygen therapy, acupuncture, exercise intervention and electrical stimulation have showed varies degrees of efficacy. With the development of scientific technology, repetitive transcranial magnetic stimulation, from which most patients can benefit, has showed a potential therapeutic ability in the field of rehabilitation afterTBI in recently years. Thus, we design the present study by producing TBI models in rats and then give a therapy of repetitive transcranial magnetic stimulation to observe the impact of rTMS on the recovery of motor function and cognitive function afterTBI through some ethology and histology parameters. Then explore the role of rTMS in the nerve repair procedure and the possible mechanism. Methods60 SD rats are randomly assigned into three groups(Sham operation group with open bone window only, TBI group with brain injury and rTMS group with brain injury and treatment of rTMS). The sham operation group treated with bone window only while the TBI group and rTMS group are treated with traumatic brain injury according to the Feeney method. All of the rats are normal raised after the brain injury, and at the 1st day after the operation, the rTMS group is treated with a 20 minutes' treatment of rTMS for 14 days while the other two groups were treated with nothing. The modified Neurological Severity Scores and the motor evoked potential of gastrocnemius are mensurated at the 1st?4th?7th and 14 th day to evaluate their neurologic function and neural pathway, and at the same time, Brd U was injected through peritoneal cavity for last test of Brd U+ cell. After the 2 weeks' treatment of rTMS, day after rTMS treatment, all of the rats were trained with the Morris water maze test to evaluate their ability of study and memory after traumatic brain injury. Finally,rats were killed and the brain of them were taken out to making sections of the injured area. The sections were managed with Nissl's staining and immunohistochemical staining of GFAP and Brd U methods to observe the cellular morphology of the injuryed area and the amount of GFAP+ and Brd U+ cells. ResultsTBI group and rTMS group both have a observably increased of m NSS score compared to Sham group, but the m NSS score of rTMS group is lower than TBI group at the 4th day(t=3.28,P=0.002),7th day(t=7.50,P<0.001) and 14 th day(t=8.67,P<0.001) day while at the 1st day their scores are of no significant difference(t=1.89,P=0.063).In the experiment of MEP, there is no significant difference of the amplitude and latent period among groups at the same stimulus intensity. A stronger intensity means a higher amplitude but the latent period turn out to be of no statistical significance. Taking the 1st quadrant for instance,Morris water maze tests told us that the sham group has the shortest escape lantency, the largest times across the platform and a largest time percent during the platform quadrant. Compared to the TBI group,rTMS group has a shorter escape latency time in the 2nd(t=4.37,P<0.001), 3rd(t=8.20,P<0.001) and 4th(t=11.24,P<0.001) day while there is no significant difference at the 1st day((t=0.72,P=0.478).And then,the rTMS group has a larger number of times across the platform(t=5.84,P<0.001) and a larger time percent in the platform quadrant(t=7.84,P<0.001) than TBI group. Nissl staining shows that the injury area of rTMS group has a larger number(t=42.08,P<0.001) and a more regular arrangement of cells than TBI group. Immunohistochemical showed that rTMS group has a higher level expression of Brd U+ cells(t=7.59,P<0.001),and a lower level expression of GFAP+ cells(t=4.03,P<0.05) than TBI group. ConclusionsEarly intervention of repetitive transcranial magnetic stimulation in TBI rats can improve the procedure of nerve repair and the regeneration of neural cells,as well as improve the ability of motor function, and promote the recovery of study and memory. |
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