Cutaneous allodynia in pediatric and adolescent patients and their mothers: A comparative study

Extended Phenotyping of Migraine in Children: A Cross-Sectional Study in a Specialist Children's Headache Clinic

BACKGROUND

The pediatric migraine phenotype may exhibit differences to adults, leading to diagnostic challenges. We aimed to perform a cross-sectional systematic study to characterize the extended phenotype of pediatric migraine.

METHODS

New migraine patients presenting to the Children's Headache Clinic were included (n = 105). Data were collected via a detailed symptom questionnaire at the first clinical encounter and were analyzed using descriptive statistics, Cohen kappa (k), Spearman correlation (ρ), and Poisson and binomial logistic regression models within SPSS.

RESULTS

Patients were 65% female and aged five to 17 years (median 14, interquartile range [IQR] 11 to 15), with a mean disease duration of 4.7 years (S.D. 2.8). Monthly headache frequency was 1 to 30 days (median 30, IQR 12 to 30). Attack duration varied between 2 and 168 hours (median 12, IQR 5 to 72). The majority (81%) experienced bilateral headache. Premonitory symptoms (PS) were reported by 93% (range 0 to 7; mood change and tiredness most commonly), cranial autonomic symptoms (CAS) by 58% (range 0 to 6; pallor and lacrimation most commonly), and premonitory CAS by 23%. Vertigo (53%) and allodynia (16%) were present. The laterality of headache and CAS showed agreement (k = 0.5, P < 0.001). For every year of disease duration, 1.07 times more PS were reported (95% confidence interval [CI] 1.03 to 1.12, P < 0.001). The number of CAS (odds ratio 2.13, 95% CI 1.2 to 3.8, P = 0.01) significantly predicted allodynia.

CONCLUSIONS

Children display a more enriched PS phenotype with disease chronicity. CAS and allodynia may be markers of central sensitization with shared neurobiological mechanisms in the absence of peripheral nociceptor activation.

Pathophysiology and Therapy of Associated Features of Migraine

Migraine is a complex and debilitating disorder that is broadly recognised by its characteristic headache. However, given the wide array of clinical presentations in migraineurs, the headache might not represent the main troublesome symptom and it can even go unnoticed. Understanding migraines exclusively as a pain process is simplistic and certainly hinders management. We describe the mechanisms behind some of the most disabling associated symptoms of migraine, including the relationship between the central and peripheral processes that take part in nausea, osmophobia, phonophobia, vertigo and allodynia. The rationale for the efficacy of the current therapeutic arsenal is also depicted in this article. The associated symptoms to migraine, apart from the painful component, are frequent, under-recognised and can be more deleterious than the headache itself. The clinical anamnesis of a headache patient should enquire about the associated symptoms, and treatment should be considered and individualised. Acknowledging the associated symptoms as a fundamental part of migraine has permitted a deeper and more coherent comprehension of the pathophysiology of migraine.