ABSTRACT
Accidents or diseases may cause impairment or even loss of human motor function, among which stroke is a disease which is most likely to cause disability and seriously endangers social health. During recent years, as a new nerve regulation technology, non-invasive brain stimulation technology can achieve the application of nerve stimulation to the brain, induce and promote neuroplasticity and improve the excitability of cerebral cortex. Especially, transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation(TMS) have shown high therapeutic potential in motor rehabilitation. This paper summarizes the mechanism and progress of the research and application of tDCS and TMS in the field of neurorehabilitation. Its technical challenges and future development trends are provided as well.
Subject(s)
Humans , Brain , Stroke , Stroke Rehabilitation , Transcranial Direct Current Stimulation , Transcranial Magnetic StimulationABSTRACT
Non-invasive brain stimulation techniques,including transcranial direct current stimula-tion (TDCS) and transcranial magnetic stimulation (TMS),are safe and non-invasive techniques,which can change the local excitability of the brain. The application of these techniques in the field of psychology,espe-cially decision making,has developed rapidly. These techniques provide the researchers a new perspective to study how people make decisions and to explore the neural mechanisms behind decision-making behaviors. This paper reviews the studies of non-invasive brain stimulation techniques in the field of different decision-making behaviors (risky choice,intertemporal choice and social decision-making) and the problems existing in the current studies,and puts forward some possible solutions.
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BACKGROUND:At home and abroad, a large number of studies have demonstrated that repetitive transcranial magnetic stimulation can evoke changes in cortical excitability that can be sustained beyond the time of stimulation, which provides a new research direction for application of magnetic stimulation in rehabilitation treatment for cerebral infarction. However, its long-term clinical efficacy and safety deserve further investigation. OBJECTIVE: To observe the influence of repetitive transcranial magnetic stimulation on nerve regeneration microenvironment in the infarcted cerebral area and rat neurological functional recovery after cerebral infarction. METHODS:The rats were randomly divided into model group, sham stimulation group and repetitive transcranial magnetic stimulation group (80%, 100% and 120% motor threshold subgroups). Right middle cerebral artery occlusion models were established in rats by the intraluminal suture method. At 24 hours after middle cerebral artery occlusion, 20 Hz repetitive transcranial magnetic stimulation was performed in each repetitive transcranial magnetic stimulation subgroup at the designated motor thresholds. Rats in the sham stimulation group underwent sham stimulation, while the model group rats were not given any treatment. RESULTS AND CONCLUSION: Seven days after middle cerebral artery occlusion, cerebral infarction volume in the repetitive transcranial magnetic stimulation group was significantly less than that in the model and sham stimulation groups (P < 0.05). RT-PCR and Western blot assays showed that at 72 hours after middle cerebral artery occlusion, aquaporin 4/9 mRNA and protein expression in the repetitive transcranial magnetic stimulation group was significantly increased than in the model group (P < 0.05). Compared with 1 day after middle cerebral artery occlusion, neurological deficit scores at 15 days after repetitive transcranial magnetic stimulation was significantly improved (P < 0.05). Immunohistochemical detection results showed that glial fibrilary acidic protein expression in the ischemic penumbra in each repetitive transcranial magnetic stimulation subgroup was significantly lower than that in the model group (P < 0.05). The results reveal that repetitive transcranial magnetic stimulation can aleviate rat neurological deficits and improve nerve regeneration microenvironment by inducing cerebral ischemic tolerance, reducing nerve cel apoptosis and decreasing aquaporin 4/9 mRNA and protein expression.
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OBJECTIVE: To investigate the effects of simultaneous, bihemispheric, dual-mode stimulation using repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) on motor functions and cortical excitability in healthy individuals. METHODS: Twenty-five healthy, right-handed volunteers (10 men, 15 women; mean age, 25.5 years) were enrolled. All participants received four randomly arranged, dual-mode, simultaneous stimulations under the following conditions: condition 1, high-frequency rTMS over the right primary motor cortex (M1) and sham tDCS over the left M1; condition 2, high-frequency rTMS over the right M1 and anodal tDCS over the left M1; condition 3, high-frequency rTMS over the right M1 and cathodal tDCS over the left M1; and condition 4, sham rTMS and sham tDCS. The cortical excitability of the right M1 and motor functions of the left hand were assessed before and after each simulation. RESULTS: Motor evoked potential (MEP) amplitudes after stimulation were significantly higher than before stimulation, under the conditions 1 and 2. The MEP amplitude in condition 2 was higher than both conditions 3 and 4, while the MEP amplitude in condition 1 was higher than condition 4. The results of the Purdue Pegboard test and the box and block test showed significant improvement in conditions 1 and 2 after stimulation. CONCLUSION: Simultaneous stimulation by anodal tDCS over the left M1 with high-frequency rTMS over the right M1 could produce interhemispheric modulation and homeostatic plasticity, which resulted in modulation of cortical excitability and motor functions.
Subject(s)
Female , Humans , Male , Brain , Evoked Potentials, Motor , Hand , Motor Cortex , Plastics , Transcranial Magnetic Stimulation , VolunteersABSTRACT
Objective:To study the masseter motor evoked potential(MEP)in patients with sleep bruxism(SB)and in healthy con-trols.Methods:30 subjects with SB and 30 healthy controls were included.MEPs were obtained by transcranial magnetic stimulation (TMS).Tests were done during daytime when the subjects were awake.The data were statistically analysed.Results:In the patients AMT was 55(52,55)%,latency of c-MEP (6.7 ±1.3)ms,the amplitude of c-MEP 0.19(0.15,0.29)mV,latency of r-MEP (2.3 ±0.4)ms,the central conduction time(CCT)4.4(3.3,5.2)ms.In the control subjects AMT was 52(52,55)%,latency of c-MEP (6.4 ±0.7)ms,the amplitude of c-MEP 0.23(0.17,0.28)mV,latency of r-MEP (2.4 ±0.4)ms,CCT 4.0 (3.4,4.4) ms.No significant difference was found between the 2 groups in the measurements evoked by TMS.Conclusion:The MEP after TMS in patients with SB is similar to that of healthy subjects,indicating that the excitability of the cortical motor system is not changed in bruxism subjects,at least when evaluated by TMS.
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The objective of this study was to test our preliminary in vivo evaluations of central cholinergic abnormalities in schizophrenia patients. Short latency afferent inhibition (SAI) is based on coupling peripheral nerve stimulation with motor cortex Transcranial Magnetic Stimulation (TMS), which has been shown to be a putative marker of central cholinergic activity. Methods: We evaluated SAI in 5 patients with schizophrenia and 5 healthy subjects. Results: The level of SAI was significantly lower in the patients with schizophrenia than in the controls (p=0.008). Conclusion: Our findings suggest involvement of central cholinergic neurotransmission in schizophrenia, which indicates a possible approach for treatment of cognitive dysfunction related to the disease.
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Due to the low response rate of antidepressant treatment in late-life depression, brain stimulation techniques should be considered when treating elderly patients. Electroconvulsive therapy (ECT) is one of the most frequently used brain stimulation techniques, and shows favorable outcome and acceptable tolerability in the treatment of late-life depression. Hemodynamic change and cognitive impairment are common side effects of ECT, which are transient in most cases. Since cognitive impairment can lead to treatment non-compliance, it should be minimized by controlling electrode position, pulse-width, treatment frequency, etc. Because ECT is followed by rapid cardiovascular change, risk factors should be evaluated and managed properly. Transcranial magnetic stimulation (TMS) and magnetic seizure therapy (MST) are also shown to be effective in treating depression, with less cognitive impairment. However, further research is needed to establish their efficacy in late-life depression.
Subject(s)
Aged , Humans , Brain , Depression , Electroconvulsive Therapy , Electrodes , Hemodynamics , Risk Factors , Seizures , Transcranial Magnetic StimulationABSTRACT
OBJECTIVE: To investigate the effects of night sleep on motor cortical excitability with TMS (transcranial magnetic stimulation) and finger tapping performance. METHOD: Eight volunteers were enrolled to investigate the effects of day wake or night sleep on motor learning and finger performance. Each subject underwent a finger tapping task over a 12 hour period, which was employed to evaluate the motor cortical excitability affected by motor learning. Starting at 9:00 am for the day wake cycle and restarting at 9:00 pm for the night sleep cycle. The finger tapping task was the index finger of the non-dominant hand with the Hangul word personal computer (PC) training program. The data was assessed by comparing the changes observed with the cortical excitability and finger tapping performance tests between the day wake and night sleep after equivalent amounts of training. RESULTS: The results showed that in paired-pulse techniques, there was a significant decrease of intracortical inhibition (ICI) in the morning following the night sleep cycle (p<0.05), but no significant change was seen in the ICI in the evening for the day wake cycle. In addition a significant decrease of the ICI was observed in comparison to the morning following the night sleep cycle and the evening following the day wake cycle (p<0.05). The 140% recruitment curve (RC) and accuracy of the finger tapping performance demonstrated a significant improvement for both cycles (p<0.05). CONCLUSION: Through this study, we observed that the Hangul typing practice requires both explicit and implicit skill learning. And also the off-line learning during a night of sleep may be affected by an inhibitory neurotransmitter related synaptic plasticity and by the time dependent learning with recruitments of remote or less excitable motor neurons in the primary motor cortex.
Subject(s)
Fingers , Hand , Learning , Magnetics , Magnets , Microcomputers , Motor Cortex , Motor Neurons , Neurotransmitter Agents , Plastics , Transcranial Magnetic StimulationABSTRACT
OBJECTIVE: To investigate the relationship between National Institute of Health Stroke Scale (NIHSS) and motor evoked potential (MEP) after stroke, measured by transcranial magnetic stimulation (TMS). METHOD: Forty six subjects with the middle cerebral artery ischaemic/hemorrhagic stroke were examined with NIHSS and TMS. According to the responsiveness of MEP in the affected muscles, subjects were divided into 2 groups: Group I consisted of 26 subjects responsive to TMS of the affected hemisphere and group II, 20 subjects unresponsive to TMS. NIHSS score was expressed as a sum of NIHSS total score, NIHSS arm and leg subscore. RESULTS: The resting motor threshold (rMT) and the amplitude of MEP in group I were 75.1% and 13.5 uV, respectively. Although NIHSS leg subscore was no statistical difference between two groups, NIHSS total score and NIHSS arm subscore in group I were statistically lower than those in group II. In group I, the rMT had a correlation with NIHSS total score and NIHSS arm subscore (r=0.39, r=0.49, p0.05). CONCLUSION: The NIHSS has relationship with cortical neurophysiological changes in the affected cerebral cortex in stroke. Therefore, it would be a useful tool to evaluate the status of motor function of hemiplegic stroke.
Subject(s)
Arm , Cerebral Cortex , Evoked Potentials, Motor , Leg , Middle Cerebral Artery , Muscles , Stroke , Transcranial Magnetic StimulationABSTRACT
OBJECTIVES: Repetitive transcranial magnetic stimulation (rTMS) is a novel, noninvasive method of brain stimulation. Since conventional rTMS does not cause seizure, marked advantage over electroconvulsive therapy (ECT), rTMS can be used easily and widely. Once the effects of rTMS on cognitive function are elucidated, its application will be further extended. However, the effects of rTMS on cognitive function have not been well examined. This study aimed to evaluate the effect of low frequency rTMS on visual short term memory. METHODS: Forty normal healthy volunteers were randomly assigned to rTMS (n=20) or sham (n=20) groups. The rTMS group were again randomly divided into left prefrontal (n=10) and right prefrontal (n=10) groups. For each group rTMS was given at 1 Hz for 20 minutes with 100% of motor threshold. As a cognitive task, Corsi Block Tapping Test (CORSI) in the computerized Vienna Test System, which can assess visual short term memory, was performed before, during, and after the rTMS. RESULTS: No significant difference was found in the visual short term memories between the rTMS and the sham groups before, during, or after 1 Hz rTMS, nor between the left and right prefrontal rTMS groups. CONCLUSION: This study demonstrates that rTMS, contrary to ECT, has no adverse visual short term memory effect when used as the standard treatment paradigm. Therefore, rTMS could be a new and safe treatment method in various neuropsychiatric fields without any interference of cognitive function.
Subject(s)
Brain , Cognition , Electroconvulsive Therapy , Healthy Volunteers , Memory , Seizures , Transcranial Magnetic StimulationABSTRACT
OBJECTIVES: Repetitive transcranial magnetic stimulation (rTMS) is a novel, noninvasive method of brain stimulation. Since conventional rTMS does not cause seizure, marked advantage over electroconvulsive therapy (ECT), rTMS can be used easily and widely. Once the effects of rTMS on cognitive function are elucidated, its application will be further extended. However, the effects of rTMS on cognitive function have not been well examined. This study aimed to evaluate the effect of low frequency rTMS on visual short term memory. METHODS: Forty normal healthy volunteers were randomly assigned to rTMS (n=20) or sham (n=20) groups. The rTMS group were again randomly divided into left prefrontal (n=10) and right prefrontal (n=10) groups. For each group rTMS was given at 1 Hz for 20 minutes with 100% of motor threshold. As a cognitive task, Corsi Block Tapping Test (CORSI) in the computerized Vienna Test System, which can assess visual short term memory, was performed before, during, and after the rTMS. RESULTS: No significant difference was found in the visual short term memories between the rTMS and the sham groups before, during, or after 1 Hz rTMS, nor between the left and right prefrontal rTMS groups. CONCLUSION: This study demonstrates that rTMS, contrary to ECT, has no adverse visual short term memory effect when used as the standard treatment paradigm. Therefore, rTMS could be a new and safe treatment method in various neuropsychiatric fields without any interference of cognitive function.