View clinical trials related to Brain Stimulation.
Filter by:Background: Sleep disturbances are highly prevalent in ageing population and patients with age-related neurodegenerative diseases, which severely affect cognition and even lead to accumulated amyloid-β (Aβ). At present, non-pharmacological interventions for sleep disturbances in dementia patients are accepted as first line of treatment, of which the evidence from clinical trials is very limited. Encouraging results from recent studies on transcranial direct current stimulation (tDCS) showed moderate positive effects on sleep quality in preclinical Alzheimer's disease (AD). Compared to tDCS, high-definition transcranial alternating current stimulation (HD-tACS) enables the entrainment of neuronal activities with optimized focality through injecting small electric current with a specific frequency and has significant enhancement effects on slow wave activities. Objectives: The investigators aim to 1) investigate and compare the safety, efficacy and sustainability of 40 Hz HD-tACS and HD-tDCS over left dorsolateral prefrontal cortex (DLPFC) in mild neurocognitive disorder due to AD (NCD-AD) patients with sleep disturbances; 2) examine the relationship between the changes in sleep quality, cognitive function and saliva Aβ levels. Methods: Chinese right-handed mild NCD-AD patients with sleep disturbances (aged from 60 to 90 years) will be randomly assigned to a 4-week intervention of either HD-tACS, HD-tDCS, or sham HD-tCS, with 33 participants per arm. Before intervention, structural magnetic resonance imaging (MRI) data is used to construct individual realistic head model. Comprehensive assessments, including sleep quality, cognitive performance and saliva Aβ levels will be conducted at baseline, 4th week, 8th week, 12th week and 24th week. Program adherence and adverse effects will be monitored throughout intervention. Data analysis: The primary outcomes will be the changes in sleep quality and memory performance with modality-driven paradigms (HD-tACS, HD-tDCS, sham HD-tCS), and comparisons of group differences across different time points. Secondary outcomes will be the changes objective sleep pattern, global cognition, saliva Aβ levels and quality of life. Intention-to-treat analysis will be carried out. Changes of efficacy indicators from baseline to each follow up point will be tested with mixed effect model. Significance: This study aims to investigate the feasibility, safety and efficacy of HD-tACS and HD-tDCS over left DLPFC for sleep disturbances and cognitive dysfunction in mild NCD-AD patients. It wills also test the program adherence, tolerability and adverse effects of this innovative neurotechonology. Information will be helpful for in-depth understanding the relationship of "sleep disturbances-amyloid deposition" and guiding the further studies of sleep medicine and neurodegenerative diseases.
This study explores the use of transcutaneous auricular vagus nerve stimulation (taVNS), a new form of neuromodulation which stimulates the ear. 24 healthy subjects without a past medical or psychiatric history will be recruited to participate in a phone screen followed by 1 lab visit. During the lab visit, subjects will participate twice in a validated stress induction technique called the cold pressor test, while concurrently receiving either active or sham taVNS. The cold pressor test consists of subjects placing their feet in an ice bath for a short period of time. Researchers will measure participant's heart rate while they receive taVNS (ear stimulation) and participate in the cold pressor test. Assessments of mood, anxiety, and stress will be collected at the beginning and end of the visit.
The main aim of this study is to assess the short-term effects of active-tDCS (a-tDCS) on the M1 regarding sensorimotor variables such as discriminative sensation, pressure pain threshold and electromyographic activity compared with a sham-tDCS (s-tDCS) in healthy individuals. The main objective was to determine whether there were clinically relevant changes generated by tDCS and if they were superior to a sham intervention.
Parkinson's disease (PD) is the second most common neurodegenerative disorder and affects approximately 1 million people in the United States with total annual costs approaching 11 billion dollars. The most common symptoms of PD are tremor, stiffness, slowness, and trouble with balance/walking, which lead to severe impairments in performing activities of daily living. Current medical and surgical treatments for PD are either only mildly effective, expensive, or associated with a variety of side-effects. Therefore, the development of practical and effective add-ons to current therapeutic treatment approaches would have many benefits. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that can affect brain activity and can help make long-term brain changes to improve functions like walking and balance. While a few initial research studies and review articles involving tDCS have concluded that tDCS may improve PD walking and balance, many results are not meaningful in real life and several crucial issues still prevent tDCS from being a useful add-on intervention in PD. These include the selection of stimulation sites (brain regions stimulated) and tDCS electrode placement. Most studies have targeted the motor cortex (brain region that controls intentional movement), but there is evidence that the cerebellum - which helps control gait and balance, is connected to several other brain areas, and is easily stimulated with tDCS - may be a likely location to further optimize walking and balance in PD. There is also evidence that certain electrodes placements may be better than others. Thus, the purpose of this study is to determine the effects of cerebellar tDCS stimulation using two different placement strategies on walking and balance in PD. Additionally, although many tDCS devices are capable of a range of stimulation intensities (for example, 0 mA - 5 mA), the intensities currently used in most tDCS research are less than 2 mA, which is sufficient to produce measurable improvements; but, these improvements may be expanded at higher intensities. In the beginning, when the safety of tDCS was still being established for human subjects, careful and moderate stimulation approaches were warranted. However, recent work using stimulation at higher intensities (for example, up to 4 mA) have been performed in different people and were found to have no additional negative side-effects. Now that the safety of tDCS at higher intensities is better established, studies exploring the differences in performance between moderate (i.e., 2 mA) and higher (i.e., 4 mA) intensities are necessary to determine if increasing the intensity increases the effectiveness of the desired outcome. Prospective participants will include 10 people with mild-moderate PD that will be recruited to complete five randomly-ordered stimulation sessions, separated by at least 5 days each. Each session will involve one visit to the Integrative Neurophysiology Laboratory (INPL) and will last for approximately one hour. Data collection is expected to take 4-6 months. Each session will include walking and balance testing performed while wearing the tDCS device. Total tDCS stimulation time for each session will be 25 minutes.
Caffeine is a psychostimulant drug. It acts as a competitive antagonist at adenosine receptors, which modulate cortical excitability as well. In deep brain stimulation (DBS), the production of adenosine following the release of adenosine triphosphate (ATP) explains the reduction of tremor. Binding of adenosine to adenosine A1 receptors suppresses excitatory transmission in the thalamus and hereby reduces both tremor-and DBS-induced side effects. Also, the effect of adenosine was attenuated following the administration of the 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX) adenosine A1 receptor antagonist. Therefore, the presence of a receptor antagonist such as caffeine was suggested to reduce the effectiveness of deep brain stimulation (DBS) in treating tremor and other movement disorders. Based on this finding, the investigators hypothesize that the antagonistic effect of caffeine can tentatively block the excitatory effects of transcranial alternating current stimulation (tACS). The plasticity effects might differ among caffeine users and non- caffeine users depending on the availability of receptor binding sites. Apart from that, a major issue in NIBS studies including those studying motor-evoked potentials is the response variability both within and between individuals. The trial to trial variability of motor evoked potentials (MEPs) may be affected by many factors. Inherent to caffeine is its effect on vigilance. In this study, the investigator shall monitor the participant's vigilance by pupillometry to (1) better understand the factors, which might cause variability in transcranial excitability induction studies and (2) to separate the direct pharmacological effect from the indirect attentional effect of caffeine.
Caffeine is a widely used psychostimulant drug and acts as a competitive antagonist at adenosine receptors. Its effect is on neurons and glial cells of all brain areas. Chronic consumption of caffeine leads to tolerance which might be associated with an increased number of binding sites in the brain. In deep brain stimulation (DBS), the production of adenosine following the release of adenosine triphosphate (ATP) explains the reduction of in tremor. Binding of adenosine to adenosine A1 receptor suppresses excitatory transmission in the thalamus and thus reduces both tremor-and DBS-induced side effects. Also, the effect of adenosine was attenuated following the administration of the 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX) adenosine A1 receptor antagonist. Therefore, the presence of a receptor antagonist such as caffeine was suggested to reduce the effectiveness of deep brain stimulation (DBS) in treating tremor and other movement disorders. In light with this finding, we anticipate that the antagonistic effect of caffeine is a culprit to the reduction of effectiveness of any stimulation protocol in non-invasive stimulation (NIBS). In particular the excitatory effects of a NIBS protocol can tentatively be blocked in the presence of caffeine. In this study, the effects of caffeine consumption on cortical excitability at the sensorimotor cortex shall be examined on focal and non-focal plasticity. Focal plasticity will be induced by paired associated stimulation (PAS) and global cortical plasticity from transcranial alternating current (tACS) stimulation. In case of tACS stimulation, 1) an excitatory protocol (tACS, 140 Hz, 1 mA) and 2) an inhibitory protocol (tACS, 140 Hz, 0.4 mA) with the active electrode over M1 and the return electrode over the orbitofrontal cortex will be used. Changes in cortical excitability are assessed using transcranial magnetic stimulation (TMS) recordings. Research goals are to examine the effects of caffeine consumption on sensorimotor cortical excitability and stimulation induced plasticity. In addition, this study explores further factors which usually contribute to variability in cortical excitability studies. The results are expected to give a useful recommendation for researchers to reduce confounding factors and hereby improves repeatability.
Social interaction (in the form of serve and return exchanges) between child and parent are crucial for psychosocial, physical and cognitive development. Parents in sub-Saharan countries are ill-equipped to maximize the benefits from this interaction. The investigators approach builds on the traditional outlook that "it takes a village to raise a child" i.e., not only the parents but other extended family members play a role as caregivers to young children. The investigators intention is to use the existing post-natal/child welfare clinics to deliver an intervention, which uses culturally acceptable videos and active skills building, to deliver health messages and practical skills to women, with the intention that they will subsequently engage and teach their partners and other caregivers about early brain stimulation and child development.
A promising form of enhancing brain function non-invasively involves stimulating the brain using weak magnetic or electric currents. This method is becoming increasingly popular in both clinical and commercial circles; a number of portable, at-home devices are available on the commercial market for personal use. In this study, the investigators aim to determine factors associated with the enhancement of cognitive and motor learning following transcranial direct-current stimulation in healthy young adults. Understanding how participants respond to brain stimulation is critical to maximizing the effectiveness of stimulation and determining its potential as a performance-enhancing aid for mental tasks. Future developments of this study may also inform the capacity of brain stimulation to act as non-drug alternative to treatment for cognitive decline.