Pupillary adrenergic sensitivity and idiopathic headache in pediatric patients.

Electronic pupillometry before and after phenylephrine eye drops was performed in 83 headache patients divided into two groups: Group A included 59 pediatric patients aged 5 to 16 years suffering from tension headache (TH = 8), common migraine (CM = 33) and classic migraine (CLM = 18); Group B comprised 24 adult patients aged 28 to 49 years suffering from CM. Comparisons were made with a group of healthy volunteer controls, 12 children and 15 adults, not suffering from headache. In Group A, only the CLM patients had significant mydriasis after phenylephrine; pupillary responses in the TH and CM cases did not differ significantly from the healthy controls, although there was an evident tendency for increased response in the CM by comparison with the TH cases. On the other hand, in Group B (adult CM) there was a significant pupillary hyper-responsiveness to adrenergic receptor stimulation, higher than in the same clinical condition in the pediatric group. In pre-pharmacological testing conditions, a significantly higher percentage of anisocoria (p less than 0.05) and a significant reduction in mean pupil size (p less than 0.01) were only evident in adult migraineurs as compared with controls. These findings suggest that a subtle chronic sympathetic deficiency affecting the iris neuromuscular junction in some clinical forms of primary headache may be detected by pupillometry at an early age. Moreover, apart from a temporal factor responsible for a progressive sympathetic imbalance during development, there may be a more evident neural transmission disorder in migraine forms as opposed to tension forms.