[Bioelectrical activity of the brain in paroxysmal and chronic forms of primary headache].

Eighty-three patients suffering from primary headache (HA) were studied. Migraine was diagnosed in 52 (migraine with aura--8, migraine without aura--30, transformed migraine--14) and headache of tension--in 31 patients. EEG was registered before treatment, using evaluation by methods of visual and spectral analyses. The EEGs of all the patients were characterized by diffuse bioelectrical activity changes. In patients with headache of tension (episodic and chronic), the reduction of alpha rhythm with simultaneous increase of other frequency bands were the main EEG features. In migraine with- and without aura, EEGs were characterized by synchronization of alpha rhythm, its spatial redistribution and increased presentation of bilaterally synchronous alpha- and theta-activity. Comparing to EEGs in migraine with episodic attacks (migraine with- and without aura), those in transformed migraine distinguished significantly by decrease of alpha rhythm. Spectral analysis revealed an increase of spectral power of frontal regions in all forms of primary HA, a total increase of theta-band power in all forms of migraine and an increase of theta-band power in frontal regions in headache of tension. Migraine with- and without aura was characterized by reduction of alpha band power in occipito-parietal hemisphere regions.