Cerebral Blood Flow in People With Multiple Sclerosis During Transcranial Direct Current Stimulation
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 3
- 试验地点
- 2
- 主要终点
- Cerebral Blood Flow
研究概览
简要总结
With this study, the investigators will substantiate if regional cerebral blood flow (CBF) is affected by tDCS, assess the amount of CBF change in relation to different currents, and measure differences in regional CBF under stimulation reactivity between healthy subjects and people with Multiple Sclerosis (PwMS)using Water O-15 PET (Water Oxygen-15 Positron EmissionTomography) imaging. The objective is to investigate the changes in regional CBF after transcranial direct current stimulation (tDCS) at different intensities (1 mA, 2 mA, 3 mA, 4 mA) in healthy subjects and PwMS. The design is a cross-sectional proof of principle study in 10 healthy subjects and 10 PwMS.
Relative regional brain CBF (rCBF) will be analyzed semi-quantitatively using voxel-wise and region of interest-based approaches. Changes in CBF associated with tDCS-application will be calculated with a general linear model in a ramp function of the task-specific rCBF, according to previous work in our group using a glucose analogue. Exploratory statistical testing will be done using a paired samples t-test between task and rest conditions and unpaired t-tests between PwMS and healthy controls at the same intensities.
With this study the investigators will be able to dose-dependently measure real-time rCBF changes after non-invasively stimulating the superficial parts of the dorsolateral prefrontal cortex (DLPFC), a commonly used target in therapeutic tDCS applications. This will provide further insight into whether tDCS is capable of inducing changes in rCBF.
详细描述
Aim 1: To determine the effects of different stimulation intensities on relative cerebral blood flow (rCBF).
Currently, researchers use tDCS as an interventional modality to modulate the excitability of the brain, with measureable changes in both motor evoked potentials and physical performances. However, because of the relatively large size of most electrodes, and the electrodynamics of the brain, it still remains unclear what specific brain structures are being stimulated and how the mechanics of stimulation (e.g., stimulation penetration and areas affected outside of target area) change with different intensities. The investigators hypothesize that regional CBF at the DLPFC (target area) will increase in a dose-dependent way with greater stimulation intensity. Furthermore, it is hypothesized that the areas surrounding the DLPFC will be increasingly affected by higher stimulation intensities.
Aim 2: To contrast the effects of transcranial direct current stimulation on relative cerebral blood flow between healthy subjects and people with Multiple Sclerosis.
PwMS typically present with glucose hypometabolism compared to their healthy peers and because CBF and glucose metabolism are highly coupled, a similar trend in CBF may be expected. Additionally, tDCS has been shown to be effective at increasing cortical excitability and glucose metabolism in both populations. However, what still remains uncertain is if PwMS and healthy subjects experience the same amount of increased activity for the same stimulation intensity. The investigators hypothesize that PwMS will experience a greater increase in rCBF at the DLPFC and surrounding areas than healthy controls for the same stimulation intensity.
Aim 3: To extend our understanding of the safety and efficacy of transcranial direct current stimulation at higher current intensities for healthy subjects and people with Multiple Sclerosis.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 18 Years 至 65 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Confirmed diagnosis of multiple sclerosis by a neurologist
- •No change in MS-specific medication (disease modification drugs) in the last three months
- •Healthy enough to complete the protocol based on information obtained from a clinical exam and past medical history.
- •An expanded disability status scale (EDSS) below 5.5
- •Comprehension of the protocol as indicated by an ability to respond to questions about the study after reading the consent form.
- •Able to use and be contacted by telephone
- •Able to speak, read, and understand English, and complete a questionnaire in English
- •Body mass index <30 kg/m2
排除标准
- •A relapse of disease symptoms in the last three months
- •History / presence of secondary conditions such as seizure disorders (or on medications known to lower seizure threshold), hydrocephalus, diabetes mellitus, or claustrophobia
- •Alcohol dependence or abuse (>2 drinks/day), or present history (last six months) of drug abuse
- •History of significant traumatic brain injury or hydrocephalus
- •Currently pregnant
- •Recent hospitalization (within the last 3 months) or enforced bed rest/sedentary state
- •Claustrophobia
- •A subject will be excluded if he/she has a contraindication to Magnetic Resonance scanning, e.g., implanted metal clips or wires, which may concentrate radiofrequency fields or cause tissue damage from twisting in a magnetic field.
- •Examples include:
- •Aneurysm clip
- •Implanted neural stimulator
- •Implanted cardiac pacemaker or autodefibrillator
- •Cochlear implant
- •Ocular foreign body (e.g., metal shavings)
- •Any implanted device (pumps, infusion devices, etc.)
- •Shrapnel injuries
结局指标
主要结局
Cerebral Blood Flow
时间窗: Through study completion, an average of 1 year
Cerebral Blood flow will be measured while subjects undergo tDCS at different intensities in the PET scanner.
次要结局
未报告次要终点
研究者
Thorsten Rudroff
Assistant Professor
University of Iowa