Summary by Alex Chen, MD
Spoon Feed
Thunderclap headache (TCH) is a concerning symptom and requires diagnostic evaluation. Initial head CT w/o contrast can help detect SAH with negative LR of 0.01 if performed within 6h of headache onset. However, a head CT w/o contrast can miss other causes of TCH and may require advanced imaging and LP.
Why does this matter?
In the US, headaches are the 5th most common ED presentation. Many of these are benign, but there are few things that make us more uncomfortable as providers than seeing the words “thunderclap headache” written in a triage note. This article aims to clarify the definition of the TCH and provides a reasonable algorithm to work through it.
“You’ve been… Thunderstruck!”
The authors did a literature search focusing on the ED management of TCH (defined as pain reaching at least 7/10 within 1 minute) and came up with a great differential and diagnostic algorithm that you should run through with TCH.
Adaptation of Table 1 in cited article (modified by Alex, edited by Thomas, Dad joke by Clay).
From cited article – Diagnostic evaluation of thunderclap headache
Source
The Thunderclap Headache: Approach and Management in the Emergency Department. J Emerg Med, 2019. https://doi.org/10.1016/j.jemermed.2019.01.026.
Reviewed by Thomas Davis
There was another article on the same topic published last year that has a slightly different algorithm that’s also worth a read:
https://www.annemergmed.com/article/S0196-0644(17)30537-1/fulltext