Dopamine Receptor Imaging to Predict Response to Stimulant Therapy in Chronic TBI
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 入组人数
- 11
- 试验地点
- 1
- 主要终点
- Perceptual Organization and Processing Speed Index
研究概览
简要总结
Deficits in memory, attention, cognitive, and executive functions are the most common disabilities after traumatic brain injury (TBI). Dopamine (DA) neurotransmission is implicated in these neural functions and dopaminergic pathways are recognized to be frequently disrupted after TBI. Methylphenidate increases synaptic DA levels by binding to presynaptic dopamine transporters (DAT) and blocking re-uptake.
The objectives of this study are to use PET imaging with [11C]-raclopride, a D2/D3 receptor ligand, before and after administering methylphenidate, to measure endogenous DA release in patients who are experiencing problems with cognition, attention and executive function in the chronic stage after TBI. In addition, we will use TMS to test short intracortical inhibition, a gamma-aminobutyric acid receptor A (GABAA) - mediated phenomenon, which is under partial DA control, as a measure of dopaminergic activity on and off
详细描述
Deficits in memory, attention, cognitive, and executive functions are the most common disabilities after traumatic brain injury (TBI). Dopamine (DA) neurotransmission is implicated in these neural functions and dopaminergic pathways are recognized to be frequently disrupted after TBI. One of the most widely used DAergic drugs is methylphenidate (Ritalin ). Methylphenidate increases synaptic DA levels by binding to presynaptic dopamine transporters (DAT) and blocking re-uptake. PET with methylphenidate challenge to measure tonic DA release provides valuable insight into the molecular basis of attention-deficit hyperactivity disorder (ADHD) and addiction, as well as practical information regarding likely effectiveness of therapy (1). The objectives of this study are to use PET imaging with [11C]-raclopride, a D2/D3 receptor ligand, before and after administering methylphenidate, to measure endogenous DA release in patients who are experiencing problems with cognition, attention and executive function in the chronic stage after TBI. In addition, we will use TMS to test short intracortical inhibition, a gamma-aminobutyric acid receptor A (GABAA) - mediated phenomenon, which is under partial DA control, as a measure of dopaminergic activity on and off
methylphenidate.
STUDY POPULATION:
Males and females (n=30), between the ages of 18 and 55 years in the chronic stage after TBI who experience deficits in neuropsychological function from TBIs incurred 6 months after the injury, will be recruited from military treatment facilities or civilian clinics when presenting for clinical management of TBI or postconcussive symptoms.
DESIGN:
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 55 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- 未提供
排除标准
- 未提供
研究组 & 干预措施
Open label methylphenidate treatment
Forced titration with methylphenidate up to a dose of 30 mg administered orally twice daily.
干预措施: Methylphenidate (Drug)
结局指标
主要结局
Perceptual Organization and Processing Speed Index
时间窗: 4 weeks
Relationship between tonic DA release (assessed by displacement of \[11C\] raclopride by oral methylphenidate) and improvement in processing speed after 4 weeks of treatment with oral methylphenidate. The Perceptual organization and processing speed index is measured from the Digit Symbol and Symbol Searches from the Weschler Adult Intelligence Scale (WAIS-IV). The tasks that comprise the PSI, (Coding, Symbol Search), are timed and require attending to visual material, visual perception and organization, visual scanning, and hand-eye coordination. It is a standardized scale were 100 is the mean of a normal population, and each 10 points represents 1 standard deviation above or below the mean. Thus, an index of 110 is 1 SD above the mean, 90 is 1 SD below the mean.
次要结局
未报告次要终点