Evaluating the Remote Effects of Stroke With MRI and PET Scans


Phase N/A Results N/A

Trial Description

Patients with stroke sometimes have a condition called diaschisis, a loss of function in a part of the brain located some distance from the original stroke-injury site. Doctors do not know why this happens.
The purpose of this study is to get a better understanding as to why diaschisis occurs by studying people who have experienced a stroke and people who have aged in good health.
Forty-four participants who are older than 40 year of age will be enrolled in this study-18 healthy people and 26 stroke patients. They will have 3 to 4 study visits. The first visit will involve a medical history and a physical and neurological exam. Participants will then have a magnetic resonance imaging (MRI) scan, either on the first visit or on a later day. On the next visit, they will undergo a position emission tomography (PET) scan. Finally, they will return for another MRI scan.

Detailed Description

Objective: Following a stroke, not only is there dysfunction of the lesioned area, but there is also remote functional depression of non-lesioned areas. This functional depression, called diaschisis, likely contributes to the functional deficit of the patient.
The objective of this study is to obtain a better understanding of the pathophysiology of diaschisis with the integrated methods of neuroimaging (positron emission tomography (PET) and proton magnetic resonance spectroscopy (H-MRS)).
Study population: We will recruit patients with subcortical stroke in the subacute state and in the chronic state, and normal controls.
Design: The stroke lesion will be the basal ganglia, internal capsule, thalamus, or cerebellum. The frontal cortex, including the motor cortex, is chosen as a remote area. Neurochemical changes in the diaschitic area will be investigated by measuring the glucose metabolic rate with PET, and concentrations of neurochemically important metabolites, such as gamma-aminobutyric acid (GABA) and glutamate, with H-MRS.
Outcome measures: Metabolic change in the diaschitic areas relative to the contra-lateral unaffected side will be calculated as a laterality index. First, this index will be compared among patient groups and control group. As a second analysis, the relationship of glucose metabolism measured by PET and concentrations of the metabolites detected by H-MRS will be evaluated.



Type Measure Time Frame Safety Issue
No outcomes associated with this trial.