Sympatholytic Effects of High Thoracic Erector Spinae Plane Block: Changes in Optic Nerve Sheath Diameter

Inclusion Criteria: * Adults with neck, shoulder, and arm pain * Those with complex regional pain syndrome The study will include 15 adult patients who are planned to receive T2-ESP block treatment. * Age between 18-65 years * Both genders * ASA physical status I-II Exclusion Criteria: * Those who refuse procedures and tests * Individuals with conditions that can increase intracranial pressure * Those with severe heart failure * Individuals with second or third-degree atrioventricular block * Those with a history of unstable angina * Individuals with COPD or chronic asthma * Those who have experienced a myocardial infarction (MI) within the last 6 weeks * Individuals with a heart rate below 50 beats per minute * Those with systolic blood pressure below 90 mmHg * Individuals with liver failure * Those with kidney failure * Individuals for whom a supraclavicular block is anatomically impossible * Those with neurological or psychological conditions that complicate test evaluation * Individuals allergic to any of the study medications * Pregnant individuals