Abstract text (incl. figure legends and references)

Background: Adult abrupt severe non-traumatic headache (thunderclap) is often related to serious underlying etiologies

such as subarachnoid hemorrhage. However, data are sparse regarding thunderclap headache in the pediatric

population.

Objective: The aim of the study was to evaluate the prevalence, characteristics and causes of thunderclap headache in

the pediatric and adolescent population, aged 6–18 years, presenting to a pediatric emergency department.

Methods: The electronic database of a tertiary care pediatric emergency department was searched for children

presenting with acute headache during 2016–2018. Headache severity was defined by pain scales, either a visual analogue

scale or by the Faces Pain Scale–Revised. The study was approved by the Research Ethics Board of Rabin Medical Center (approval no. RMC-19-704). Due to the retrospective study design, the committee waived the need for informed consent

Results: During the three-year study period, 104,086 children and adolescents aged 0-18 years were admitted to the pediatric emergency department; of them, A total of 2290 children, aged 6-18 years (mean 13.3 ± 3.26) were admitted with a chief complaint of headache, and reported their level of pain according to one of the two scales used 3112 (3%) presented with acute headaches Thunderclap headache was diagnosed in 19/2290 (0.8%) of the included patients, all of them with a pain score

of 10/10. All the patients had a benign course. Primary headache was diagnosed in 15/19 (78.9%), six patients had

migraine and eight were diagnosed with primary thunderclap headache. Four of the 19 patients were diagnosed with

secondary headache: three with infectious causes and one with malignant hypertension.

Conclusions: Thunderclap headache is rare among children and adolescents presenting to the emergency department. This headache is generally of a primary origin. Extensive evaluation is still needed to rule out severe diagnosis problems.