Investigating the Neurobiologic Basis for Loss of Cortical Laterality in Chronic Stroke Patients
试验速览
- 阶段
- 早期 1 期
- 状态
- 已完成
- 入组人数
- 44
- 试验地点
- 2
- 主要终点
- Compare the ratio of gluatamte and gaba concentrations within the contralesional primary motor cortex
研究概览
简要总结
In healthy individuals, unimanual movement (with either the left or right hand) is associated with activity in a network of predominantly contralateral brain regions, including the primary motor cortex (PMC). This laterality is often compromised following a middle cerebral artery (MCA) stroke. Neuroimaging studies of these patients have shown that unimanual movements with the effected hand are associated with elevated Blood Oxygen-Level Dependent (BOLD) signal in both the lesioned and the nonlesioned primary motor cortices. Elevated activity in the contralesional PMC is well-established in chronic stroke patients and is associated with poor motor rehabilitation outcomes. Yet the neurobiologic basis for this aberrant neural activity is equivocal. The overarching goal of this project is to determine the neurobiologic basis for elevated activity in the contralesional primary motor cortex.
详细描述
One factor that may contribute to elevated activity in the contralesional PMC is increased cortical excitatory tone within the contralesional hemisphere (Aim 1).
While approximately 80% of the descending corticospinal neurons that control the right hand originate in the left PMC, 20% originate in the right PMC. Elevated activity in the right PMC of left-sided stroke patients may reflect compensatory activity of these descending fibers. Neural activity in the PMC reflects the balance of local excitatory (glutamatergic) and inhibitory (GABAergic) processing. It can be measured in two manners: 1) electrophysiologically, using single hemisphere paired pulse transcranial magnetic stimulation (TMS), and 2) neurochemically, using magnetic resonance spectroscopy (MRS).
Another factor that may contribute to elevated activity in the contralesional PMC is a loss of transcallosal inhibition between the hemispheres (Aim 2). During right hand movement, the left PMC of healthy individuals actively inhibits the right PMC via inhibitory projections through the corpus callosum. In left MCA stroke patients, elevated activity in the contralesional (right) PMC when moving the right hand may reflect a loss of typical inhibition from the left PMC. The integrity of inter-hemispheric information transfer can be measured in two manners: 1) using bi-hemispheric paired-pulse TMS, and 2) using a multimodal brain stimulation/brain imaging approach, interleaved TMS/MRI.
Through interleaved TMS/MRI, the investigators can selectively stimulate the ipsilesional PMC and quantify the amount of TMS-induced activity in the contralesional PMC. These two explanations will be tested through a cross-sectional investigation of neural function in left MCA stroke patients with mild-moderate right upper extremity impairment and controls matched for age and cardiovascular risk factors. To assess the clinical relevance of these factors on motor dysfunction, the investigators will perform a detailed kinematic assessment of movement efficiency, smoothness and compensation (Aim 3).
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Diagnostic
- 盲法
- None
入排标准
- 年龄范围
- 21 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- 未提供
排除标准
- 未提供
研究组 & 干预措施
Healthy Controls
Subjects will undergo the following diagnostic tasks and assessments: Rasch Modified Version of the Fugl-Meyer Motor Assessment, Anatomical Image Acquisition, and the Functional MRI Task and Acquisition
干预措施: Rasch modified version of the Fugl-Meyer Motor assessment (Diagnostic Test)
Healthy Controls
Subjects will undergo the following diagnostic tasks and assessments: Rasch Modified Version of the Fugl-Meyer Motor Assessment, Anatomical Image Acquisition, and the Functional MRI Task and Acquisition
干预措施: Anatomical image acquisition (Diagnostic Test)
Healthy Controls
Subjects will undergo the following diagnostic tasks and assessments: Rasch Modified Version of the Fugl-Meyer Motor Assessment, Anatomical Image Acquisition, and the Functional MRI Task and Acquisition
干预措施: Functional MRI task and acquisition (Diagnostic Test)
Stroke Participants
Subjects will undergo the following diagnostic tasks and assessments: Rasch Modified Version of the Fugl-Meyer Motor Assessment, Anatomical Image Acquisition, and the Functional MRI Task and Acquisition
干预措施: Rasch modified version of the Fugl-Meyer Motor assessment (Diagnostic Test)
Stroke Participants
Subjects will undergo the following diagnostic tasks and assessments: Rasch Modified Version of the Fugl-Meyer Motor Assessment, Anatomical Image Acquisition, and the Functional MRI Task and Acquisition
干预措施: Anatomical image acquisition (Diagnostic Test)
Stroke Participants
Subjects will undergo the following diagnostic tasks and assessments: Rasch Modified Version of the Fugl-Meyer Motor Assessment, Anatomical Image Acquisition, and the Functional MRI Task and Acquisition
干预措施: Functional MRI task and acquisition (Diagnostic Test)
结局指标
主要结局
Compare the ratio of gluatamte and gaba concentrations within the contralesional primary motor cortex
时间窗: Through study completion, an average of two weeks
Using spectroscopy investigators will determine if the ratio of glutamate/GABA is higher in stroke patients than controls. Furthermore, in healthy controls prepulse inhibition will be positively correlated with the concentration of GABA, and prepulse facilitation will be positively correlated with the concentration of glutamate. Although we expect this relationship to be true in both the controls and the stroke patients, variation from this pattern in the stroke patients would suggest that there is another factor beyond simple within-hemisphere measurements that is affecting the contralesional cortex activity.
次要结局
- Quantify the relationship between neural activity and motor performance using the Rasch modified version of the Fugl-Meyer motor assessment battery to acquire three aspects of motor performance for all individuals in both groups.(Through study completion, an average of two weeks)