TSPO PET as a Measure of Post-stroke Brain Inflammation: a Natural History Cohort

DESIGN: exploratory, prospective, natural history, imaging cohort study BACKGROUND: Stroke causes a strong inflammatory response in the brain which is thought to contribute to permanent brain damage in stroke patients. To develop new therapies targeting inflammation we need to better understand how inflammation affects the injured brain tissue and how it relates to neurological deficits that directly affect the patients' quality of life. AIMS: To track the extent and location of inflammation in the brain after stroke over a period of 90 days. The study will explore whether the most inflamed areas in the brain undergo the most damage after stroke and correspond to the cognitive and neurological deficits experienced by stroke patients. METHODS: The study involves an initial screening visit and 2 study imaging visits at days 15 and 90 after the stroke episode. Patients will undergo: 1. Two 90-minute brain imaging sessions using Positron Emission Tomography (PET) (involves injection of safe radiotracers which attach to brain immune cell markers TSPOs and light up the inflamed areas in the brain), 2. Two 45-90 minute Magnetic Resonance Imaging (MRI) scanning sessions (include administration of safe chemical contrast agent Gadolinium), 3. Physical and neurological examinations (vital signs, assessments of mobility and cognitive functioning), 4. Blood testing (routine measurements, blood inflammation markers, and genetic testing for TSPO marker). Venous cannula will be inserted into the forearm for the duration of the scans. POPULATION: 15- 25 patients (recruitment will cease once 15 patients have completed the study) ELIGIBILITY: Male and female stroke patients, aged 18-85, with a recent (within last 10 days) ischemic stroke of moderate severity, able and willing to provide informed consent LOCATION: Patients will be recruited at the Charing Cross Hospital, Imperial College Healthcare NHS Trust, and study scans will be performed by Invicro Centre for Imaging Scien