Recent data suggest that common migraine, particularly catamenial (menstrual), is characterized by dopaminergic (DA) receptor supersensitivity. This dopaminergic dysfunction may be related to gonadal steroidal patterns (abnormal estrogen/ progesterone ratio).
In order to distinguish between altered DA-neurotransmission and the effect of sex hormones we studied prolactin (PRL) response to drugs considered direct and indirect DA-agonists in a group of prepubertal children with common migraine, in whom the effect of sex hormones is minimal.
Basal PRL plasma levels were measured every 30 minutes up to 240 minutes, after oral administration of L-DOPA, nomifensine, lisuride and placebo in headache-free migraineurs. Results obtained show no significant differences in plasma PRL levels between migraineurs and control subjects. This suggests that in a situation of reduced interferences by sex hormones, inhibitory TIDA (tuberoinfundibular dopaminergic) function may be normal. However a drawback of our study may have been that we were inhibiting TIDA function in prepubertal subjects with already low baseline prolactin levels. It is our belief that further understanding of dopaminergic involvement in childhood migraine may come from studies utilizing substances that enhance prolactin levels through dopaminergic inhibition.