Thunderclap headache is a sudden, high-intensity headache often associated with sub-arachnoid hemorrhage secondary to a ruptured intracerebral aneurysm. A variety of less common causes have now been described. This report presents the cases of 2 patients who experienced thunderclap headache after regrowth of an aneurysm, without hemorrhage of previously coiled aneurysms. Thunderclap headache after endovascular occlusion of a ruptured intracranial aneurysm may be a symptom of aneurysm regrowth and may warrant angiographic investigation.
Byrum, E. P., McGregor, J. M., & Christoforidis, G. (2009). Thunderclap headache without subarachnoid hemorrhage associated with regrowth of previously coil-occluded aneurysms. American Journal of Neuroradiology, 30(5), 1059–1061. https://doi.org/10.3174/ajnr.A1382