Abstract
The term "thunderclap headache" (TCH) was first coined in 1986 by Day and Raskin to describe headache that was the presenting feature of an underlying unruptured cerebral aneurysm. The term is now well established to describe the abrupt onset headache seen with many other conditions and is also now included in The International Classification of Headache Disorders 3(rd) edition beta version rubric 4.4. An essential to label an acute headache as "TCH" and differentiate it from other "sudden onset, severe headaches" is the arbitrary time frame of 1 min from onset to peak intensity for "TCH." What happens in practice, however, is that even those "sudden onset, severe headaches" that do not strictly fulfill the definition criteria are also labeled as "TCH" and investigated with the same speed and in the same sequence and managed based on the underlying cause. This article begins by questioning the validity and usefulness of this "one minute" arbitrary time frame to define "TCH," particularly since this time frame is very difficult to assess in practice and is usually done on a presumptive subjective basis. The article concludes with suggestions for modification of the current investigation protocol for this emergency headache scenario. This proposal for "a change in practice methodology" is essentially based on (1) the fact that in the last two decades, we now have evidence for many more entities other than just subarachnoid hemorrhage that can present as "TCH" or "sudden onset, severe headache" and (2) the evidence from literature which shows that advances in imaging technology using higher magnet strength, better contrast, and newer acquisition sequences will result in a better diagnostic yield. It is therefore time now, in our opinion, to discard current theoretical time frames, use self-explanatory terminologies with practical implications, and move from "lumbar puncture (LP) first" to "LP last!"