Electroencephalographic examination of 64 Danish Turner girls.

An EEG study of 64 Danish Turner girls and age-matched controls was made. The characteristic findings in the basic EEG rhythms of Turner girls were: 1) alpha activity of more rapid frequency (10.5+ Hz), lower amplitude (-20 microV, lower amount (-30%) and diffuse areas, 2) beta activity of slower frequency (14-18 Hz), higher amplitude (10-20+ microV), higher amount (50+ %) and diffuse areas, and 3) theta activity of higher amount (30+ %) than controls. Dominant EEG rhythm was more rapid and aging effect was more pronounced in Turner girls than in the controls. Marked or moderate asymmetry was observed in 15 Turner girls compared with three controls (p less than 0.01). Asymmetry was most pronounced at the occipital (p less than 0.01) and parietal area (p less than 0.02), but not so at the frontal, temporal or central areas. In 64 Turner girls, paroxysmal EEG abnormality was found in one, paroxysmal, slight abnormality in 13, basic abnormality in three and normal/borderline in 47. The EEG diagnosis did not differ in Turner and control girls. The characteristic findings in the basic EEG rhythm and dominant rhythm were more pronounced in Turner girls with 45,X than in those with other karyotypes, who showed some similarity to the controls. Our findings indicate that Turner girls have a functional brain disorder more often than the controls, particularly at the occipital and parietal areas and in those with hemispheric differences most often in the right hemisphere. Further studies comprising 24-h EEG investigation and blood flow studies were suggested.