Clinical Research Directory

Inclusion Criteria: * Age 18 to 75 years, inclusive. * Verified pathological deformation of the internal carotid artery, including tortuosity, kinking, and/or coiling, confirmed by duplex ultrasound and/or angiographic imaging. * Ability to undergo baseline clinical and neurological assessment and longitudinal follow-up. * Written informed consent for participation and processing of personal data. Separate optional consent may be obtained for storage of residual biospecimens and genetic testing, where applicable. Exclusion Criteria: * Acute ischemic or hemorrhagic stroke within 6 months before planned enrollment if the participant's condition prevents valid baseline assessment or study procedures. * Complete occlusion of the study internal carotid artery or brachiocephalic trunk that prevents valid assessment of the pathophysiological role of arterial tortuosity. * Hemodynamically significant atherosclerotic stenosis of the internal carotid artery greater than 50% on the side relevant to the analysis when it represents the dominant alternative cause of impaired blood flow. * Unstable angina, NYHA class III-IV heart failure, or another decompensated cardiovascular condition that prevents safe participation. * Myocardial infarction within the previous 3 months. * Severe cognitive impairment or dementia preventing valid informed consent or neuropsychological assessment, unless participation is legally permitted through an authorized representative. * Active malignancy or systemic treatment expected to substantially affect the investigated biomarkers or prognosis. * Decompensated respiratory, renal, or hepatic disease that may substantially affect safety or interpretation of study results. * Psychiatric disorder or other condition preventing adequate communication or adherence to the study protocol.