Primary headache pathophysiology in children: the contribution of clinical neurophysiology

Although primary headaches are very prevalent also in pediatric age, most neurophysiologic studies in these diseases concerned only the adulthood. The neurophysiologic investigation of the pathophysiological mechanisms subtending migraine and tension-type headache in children and adolescents could be particularly interesting, since during the developmental age the migrainous phenotype is scarcely influenced by many environmental factors that can typically act on adult headache patients. The neurophysiologic abnormality most frequently found in adult migraineurs, that is the reduced habituation of evoked potentials, was confirmed also in migraine children, although it was shown to involve also children with tension-type headache. Some studies showed abnormalities in the maturation of brain functions in migraine children and adolescents. While the visual system maturation seems slowed in young migraineurs, the psychophysiological mechanisms subtending somatosensory spatial attention in migraine children are more similar to those of healthy adults than to those of age-matched controls. There are some still unexplored fields that will have to be subjects of future studies. The nociceptive modality, which has been investigated in adult patients with primary headaches, should be studied also in pediatric migraine. Moreover, the technique of transcranial magnetic stimulation, not yet used in young migraineurs, will possibly provide further elements about brain excitability in migraine children.