Causes and management of thunderclap headache: a comprehensive review.

BACKGROUND: Thunderclap headache (or sudden severe headache) is an uncommon type of headache. Recognition and accurate diagnosis of this headache are important, because there is often a serious underlying brain disorder. SUMMARY: In this article, causes and management of thunderclap headache are discussed. In the primary care setting, there is a serious cause in one third of patients, but in the hospital setting, up to two thirds of patients have a serious underlying brain disorder. Clues in history and physical examination can point to a possible serious underlying cause of thunderclap headache, such as subarachnoid hemorrhage, intracranial hematoma, or cerebral venous thrombosis. The remaining patients with thunderclap headache, however, have a primary headache disorder, such as migraine or (less frequently) tension headache with an unusual sudden onset, exertional headache, coital headache, cough headache, or cluster headache. The concept of thunderclap headache as a distinct clinical entity is discussed, with implications for its evaluation. Present radiological techniques are reviewed with regard to their diagnostic utility in detecting a serious brain disorder. CONCLUSIONS: Thunderclap headache is an uncommon type of headache, and a serious underlying cause should be excluded.