[Photosensitivity in children with idiopathic headaches].

The occipital lobe involvement in the pathogenesis of the migraine aura, frequent occurrence of photogenic stimuli as the provoking factors of a migraine attack, still unsatisfactory explanation of the relation between migraine and epilepsy have drawn our attention to the photosensitivity in the idiopathic headaches, particularly in the developmental period. Photosensitivity is detected in EEG as a paroxysmal response to intermittent photic stimulation. This reaction called a photoparoxysmal response (PPR) has to be regarded as genetically determined EEG-symptom and occurs in 1.3-1.4% of healthy individuals aged 6-18. The aim of the study was to compare the frequency and identify the type of PPR in idiopathic headaches in children: with migraine with aura, without aura and with tension-type headache as well as to find the possible correlation between PPR and migraine photogenic triggering factors in children and adolescents aged 7-18. In years 2001-2003 263 EEG records were performed in patients hospitalized because of idiopathic headaches: 77 with the diagnosis of migraine with aura, 112 - migraine without aura, 74--in tension-type headache. The Fisher exact test was used to compare the number of patients with positive PPR and those with photogenic triggering factors of a migraine attack. The frequency of PPR did not differ significantly in three types of idiopathic headaches and accounts for 7.8% in migraine with aura, 8.9%--migraine without aura and 6.7%--in tension-type headache. PPR was most frequent (17.6%) in a group of children under 12 years of age with migraine with aura. In the migraine with aura PPR had the form of the general paroxysmal of the spike, polyspike and wave in 11.8%, localized changes in the temporal-parietal-occipital region only in 5.9%. In 7/17 patients with migraine and PPR, photogenic stimuli were most frequent provoking factors for the migraine attack (in controls without PPR 10/100) (p<0,01). Frequent coexistence of PPR and photogenic provocation of the migraine attack in children and adolescents supports the theory about general cortical hyperexcitability in migraine.