Feasibility, Utility, and Interrater Reliability of the Cluster Headache Severity Scale, Cluster Headache Quality of Life, Cluster Headache Index, and 6-Item Headache Impact Test in Pediatric Cluster Headache.

Cluster headache is rare in children and only a few clinical studies have systematically evaluated cluster headache in children. This study was conducted between August 2019 and December 2021 with the primary aim to evaluate the feasibility and utility of the Cluster Headache Severity Scale in determining the severity of cluster headache in patients aged less than 18 years and monitoring response to prescribed treatment. Secondary objectives were to evaluate the feasibility and utility of Cluster Headache Quality of Life, Cluster Headache Index, and 6-item Headache Impact Test in pediatric cluster headache patients to assess the quality of life, severity, and impact of cluster headache. A total of 32 children (age of onset 11.9 ± 2.3 years, age of diagnosis 13.7 ± 2.4 years, 68% boys) were enrolled. Although 30 cases had their headache episodes occurring during nighttime, only 16 children had a Children's Sleep Habits Questionnaire (CSHQ) score >41 at baseline. All children responded to prednisolone as bridging therapy and 23 of 32 showed adequate pain relief after sumatriptan nasal spray for an acute attack. The average time taken for completion of Cluster Headache Index, Cluster Headache Severity Scale, Cluster Headache Quality of Life, and Headache Impact Test-6 scores were 5.2 ± 0.7, 5.1 ± 0.8, 27.4 ± 3.5, and 6.2 ± 0.8 minutes, respectively. The interrater reliability was good for Cluster Headache Severity Scale, Cluster Headache Quality of Life, and Headache Impact Test-6 (Cronbach α 0.93, 0.81, and 0.89, respectively). There was a strong positive correlation between the Cluster Headache Severity Scale score with Headache Impact Test-6 score and Cluster Headache Quality of Life score (correlation coefficient  = 0.90 and 0.98). Majority of pediatric cluster headache patients are likely to respond to prednisolone and sumatriptan. Cluster Headache Severity Scale, Cluster Headache Quality of Life, and Headache Impact Test-6 can be used for pediatric cluster headache patients for treatment monitoring.