INflammation and Small Vessel Disease Study

Inclusion Criteria: * Have given written informed consent to participate * Be aged 40 years and over * Have symptomatic cerebral small vessel disease (SVD) defined as: * Clinical lacunar stroke syndrome with lacunar infarct, as defined by the Standards for Reporting Vascular Changes on Neuroimaging (STRIVE) criteria * And/OR Symptoms of cognitive impairment due to SVD with lacunar infarct on MRI * And/OR Gait apraxia/motor impairment presumed due to SVD with lacunar infarct on MRI Exclusion Criteria: * Unable/unwilling to consent including lack of capacity to consent * Contraindications to taking part in MRI study as assessed by the local MRI safety questionnaire, e.g., pacemaker * Vaccination or infection with fever in preceding month * Any stroke cause other than SVD including: * Cardioembolic source * Carotid or vertebral stenosis \> 50% measured on NASCET (North American Symptomatic Carotid Endarterectomy Trial) criteria * Myocardial infarction in past year * Auto-immune/auto-inflammatory disease * Use of immunomodulating drugs * Estimated glomerular filtration rate (eGFR) =\<59 ml/min/1.73m2 within past 3 months for Cambridge, and eGFR =\<29 ml/min/1.73m2 within past 3 months for Nijmegen, in line with local guidelines. Estimated GFR will be calculated using the Modification of Diet in Renal Disease (MDRD) equation: 186 x (Creatinine / 88.4)-1.154 x (Age)- 0.203 x (0.742 if female) x (1.210 if black). Creatinine will be checked within 3 months of the MRI, and if this has not been done as part of clinical care it will be performed as a research procedure. * Another diagnosed chronic neurological condition (e.g. Alzheimer's, Parkinson's disease, motor neurone disease, multiple sclerosis). * Limited life expectancy due to another illness or chronic condition making the 2-year follow-up difficult (e.g. widespread malignancy). * Known monogenic cause of small vessel disease (e.g. CADASIL - Cerebral Autosomal Dominant Arteriopathy with Sub-cortical Infarcts and Leukoencephalopathy)