Thunderclap Headache Without Subarachnoid Hemorrhage: The Role of RCVS in Non-Hemorrhagic Presentations

Reversible Cerebral Vasoconstriction Syndrome (RCVS) is a rare but increasingly recognized neurological illness characterized by sudden, severe "thunderclap" headache with temporary vasoconstriction of cerebral arteries. While RCVS is normally self-limiting, the danger of devastating complications, including stroke and intracranial hemorrhage, justifies prompt detection. A main challenge to diagnosing RCVS is the differentiation of this condition from other potentially life-threatening conditions, most notably subarachnoid hemorrhage (SAH).This review focuses on an uncommon yet clinically significant presentation—RCVS manifesting with a thunderclap headache but without any evidence of bleeding on imaging. We explore the pathophysiology of RCVS, risk factors, and the key diagnostic tools that help differentiate it from mimics like SAH and primary angiitis of the central nervous system. Additionally, we discuss current treatment strategies, emphasizing the role of calcium channel blockers and supportive care to prevent complications .By the clarification of this characteristic presentation, the present review seeks to increase the knowledge of healthcare professionals and, thus, their ability for the recognition and treatment of RCVS. Due to the symptomatic similarity with more dangerous conditions, the development of criteria indicating RCVS without SAH may lead to earlier treatments and better results in patients.