Overview

The goal of this observational study is to

• to investigate the prevalence and time course of autonomic dysfunction in acute ischemic stroke patients;
• to evaluate the influence of lesion location on autonomic dysfunction;
• to identify patterns of structural and functional brain connectivity within the central autonomic control circuits associated with autonomic dysfunction; and
• to explore causal models of the link between brain lesions; cardiac, immunological and endocrine biomarkers; and dysautonomia.

Researchers will compare patients with acute ischemic stroke to patients with transient ischemic attacks to study the effect of acute ischemic brain lesions.

Participants will

• undergo cardiovascular autonomic function testing;
• receive structural and functional MR imaging;
• provide blood samples for determinaton of serological biomarkers auf dysautonomia.

Eligibility

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).