Pupillary Adrenergic Sensitivity and Idiopathic Headache in Pediatric Patients

Abstract

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.

Dysfunction of the pupillary light reflex following migraine headache

“…However,the persistence of the sympathetic instability in the migraine free interval was found in previous pupillometric studies [4,8] and in investigations of cardiovascular parameters [3,15,23,33].Therefore we propose an additionally central sympathetic instability that affects the sympathetic innervation of the eye, the arteries and the blood pressure. A sympathetic instability of the blood pressure or the arterial tone might contribute to migraine headache via an excitation of the surrounding trigeminal sensory nerve fibers.…”

“…Therefore, another possible reason for the observed parasympathetic dysfunction could be a central sympathetic hyperfunction during the attack. In previous studies employing pupillometry, no evidence for sympathetic hyperfunction during an attack was found [4,12,17]. If we assume a central sympathetic hypofunction, the parasympathetic tone could have been more pronounced during the attack due to less central sympathetic inhibition.…”

“…In 30 migraine patients with unilateral headache,there was no difference in pupillary size on the symptomatic side as compared to the non-symptomatic side. Battistella et al also detected a smaller pupillary diameter and a higher degree of anisocoria in adult migraine patients [4]. Drummond reported a smaller pupillary diameter on the symptomatic side [8].…”

“…Between successive attacks of migraine and during an attack, a smaller pupil diameter and a higher degree of anisocoria with smaller pupil size on the symptomatic side has been observed [4,8]. After local bilateral direct sympathetic activation by application of drugs such as cocaine and phenylephrine, pupillary dilatation was more pronounced in migraine sufferers than in controls [4,12,17], suggesting central sympathetic dysfunction [12].…”

The optometric correlates of migraine

“…In contrast to the findings of Drummond (1987Drummond ( , 1990, De Marinis et al claimed that the oculosympathetic hypofunction was not related to headache side and was temporally related to the migraine attack, being absent after 15 days. Battistella et al (1989) showed that this sympathetic hypofunction existed in children with migraine but to a lesser extent which suggests a progression of the sympathetic hypofunction from childhood into adulthood.…”