Among patients with thunderclap headache who were admitted to the four participating hospitals, who has diffuse segmental vasoconstriction on CT angiography or MR angiography will be eligible for the study. Participants who meet the definition of RCVS will be enrolled as the case-patients and others will be enrolled as control-patients. The RCVS group will be defined when two or more neurologists agree by the clinical features and angiographic findings. The result of tests for varicella zoster virus titer will not be opened to neurologists until the end of the study. For case and control patients, tests for varicella zoster virus infection are (1) Pre-existing virological markers (ex. VZV-IgG, IgM, and VZV PCR in CSF or Skin lesion if present) (2) VZV-specific cell mediated immune response (CMI) at the time of admission and one month later (3) VZV in blood measured by quantitative test of viral load with real-time PCR and digital PCR for latent viral load (4) Quantitative test of viral load with real-time PCR in saliva at time of admission and one month later. Reactivation or infection of VZV of patients with RCVS and controls will be compared.
Age range
20 Years – 79 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Infection or reactivation of varicella zoster virus (VZV)
Timeframe: At the time of enrolled.