Imaging and Serological Biomarkers of Autonomic Dysfunction After Ischemic Stroke

Inclusion Criteria: * Diagnosis of either * acute ischemic stroke with either an ischemic lesion visible on CT/MRI or persistent focal deficits 24 hours after symptom onset, or * Transient ischemic attack with transient clinical deficits including motor or speech disturbance and not restricted to isolated vertigo/dizziness, visual disturbance, or sensory disturbance. * symptom onset within 72h prior to hospital admission, * a pre-stroke/TIA ability to walk without help from another person (modified Rankin scale score \< 4), * age \> 18 years, and * informed consent by either the patient or a legal representative (including a spouse) Exclusion Criteria: * In-hospital stroke, * contraindications to MR imaging (e.g., claustrophobia, pregnancy, pacemakers, implants), * known moderate to severe dementia, * previous structural brain damage (except leukoariosis due to cerebral small vessel disease), * hemodynamically relevant stenosis of the common or internal carotid artery, or * left heart failure with estimated left ventricular ejection fraction \< 50%, * concomitant systemic illness that can lead to dysautonomia, such as an active infection, thyroid disease, or neurodegenerative disorder (e.g. PD, MSA).