[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-studies-list:{\"conditionNormalized\":\"sympathetic-activity\",\"overallStatus\":[\"RECRUITING\",\"AVAILABLE\",\"NOT_YET_RECRUITING\"],\"orderBy\":\"LastUpdateSubmitDate:desc\",\"size\":25,\"offset\":0}":3,"health-study-condition:sympathetic-activity":47},{"pageToken":4,"total":5,"offset":6,"count":5,"results":7},null,1,0,[8],{"id":9,"slug":4,"hasResults":10,"nctId":11,"briefTitle":12,"officialTitle":13,"acronym":14,"eligibilityCriteria":15,"healthyVolunteers":16,"sex":17,"minAge":18,"maxAge":19,"enrollmentInfo":20,"targetDuration":4,"studyType":23,"phases":24,"briefSummary":26,"conditions":27,"keywords":30,"overallStatus":35,"whyStopped":4,"lastUpdateSubmitDate":36,"lastUpdatePostDateStruct":37,"startDateStruct":40,"completionDateStruct":42,"leadSponsor":44,"locationsCount":5},"100625950",false,"NCT07429292","SPARK Study - Sympathetic Periarterial Radial Block in Healthy Volunteers","SPARK Study - Sympathetic PeriArterial Radial blocK Study","SPARK","Inclusion Criteria:\n\n* Age 18-50 years\n* ASA physical status I-II\n* Able to understand and provide informed consent\n* Able to comply with study procedures and follow-up\n* Two hands with 5 intact digits and no significant upper extremity injury\n\nExclusion Criteria:\n\n* Allergy to lidocaine or similar anesthetics\n* Allergy to adhesives or ultrasound gel\n* Neuromuscular, autonomic, or major vascular disorders affecting upper extremities\n* Peripheral neuropathy\n* Raynaud's phenomenon or digital ischemia\n* Coagulopathy or anticoagulation\n* Active skin infection near block site\n* Pregnancy\n* BMI \\> 35 kg\u002Fm²\n* Inability to tolerate cold exposure\n* Any condition interfering with study conduct",true,"ALL","18 Years","50 Years",{"count":21,"type":22},20,"ESTIMATED","INTERVENTIONAL",[25],"PHASE4","The SPARK Study evaluates changes in peripheral sympathetic vasomotor activity following a targeted, ultrasound-guided periarterial sympathetic block of the distal radial artery in healthy volunteers. Autonomic reactivity will be assessed before and after the block using digit-specific pulse-amplitude index and infrared thermography during standardized cold pressor testing.",[28,29],"Healthy Volunteers","Sympathetic Activity",[31,32,33,34],"Sympathetic Block","Radial Artery","Cold Pressor Test","Periarterial block","NOT_YET_RECRUITING","2026-06-16",{"date":38,"type":39},"2026-06-17","ACTUAL",{"date":41,"type":22},"2026-09",{"date":43,"type":22},"2027-04",{"name":45,"class":46},"Duke University","OTHER",""]