Paroxysmal hemicrania in children and adolescents: A systematic review.

Objective: We aimed to report the accessible demographic, clinical, and radiological characteristics of reported pediatric paroxysmal hemicrania (PH).

Introduction: It has been a while since PH in a child was first described. However, it is still unknown whether children's PH follows the same patterns as adults.

Methods: This study followed the latest version of PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). PubMed, Web of Science, and Scopus were searched systematically without time limitation. We included all English-language, peer-reviewed articles, including observational or interventional studies reporting PH cases in children or adolescents based on the International Classification of Headache Disorders (ICHD) criteria. Data extracted included PH class; sex; age; age of onset; frequency, duration, site, severity, and quality of pains; triggers; and autonomic and migrainous symptoms, as well as a sense of restlessness/agitation, response to treatment, laboratory investigations, imaging, comorbidity, and family history. For quality assessment, two independent reviewers (MB and VM) assessed the methodological quality of the included studies through the Joanna Briggs Institute's critical appraisal checklist.

Results: A total of 182 records were identified and reduced to 116 after removing duplicates. After screening, 22 articles met the inclusion criteria. Overall, the studies represented 35 children or adolescents with PH. We found a boy-to-girl ratio of 1.125:1. Onset occurred at a broad range of 1 to 14 years old. The mean age of onset among reported cases in children and adolescents was 6.5 years, while the mean age of diagnosis was 8.2 years. [Correction added on 22 August 2022, after first online publication: In the preceding sentence, 6.3 and 7.9 years were changed to 6.5 and 8.2 years, respectively.] The attacks' frequency and duration were greatly varied. Left-sided pain occurred twice as often as right-sided pain. The characteristics of the pain were usually severe in intensity. In nearly all of the cases, it was accompanied by ipsilateral cranial autonomic features. While most attacks were spontaneous, there were some common triggers. The physical examination, electroencephalogram, and brain magnetic resonance imaging had normal findings. Almost all patients benefited from indomethacin and showed complete responses to treatment, while some needed combination treatment of indomethacin with other medications.

Conclusion: Although pediatric-onset PH has similar features to adult-onset PH, there are some challenges with ICHD criteria for younger children that limit the ability to confidently assign a diagnosis. Moreover, owing to concomitant migrainous features, PH may be confused with migraine in children and adolescents.