Quantified electroencephalogram in adult patients with Down's syndrome

The aim of this study was the assessment of quantified EEG (qEEG) changes in adult patients with Down's syndrome (DS) with different degrees of mental retardation. Forty-five patients, 33 aged 20 - 35 years (young DS patients, Y-DS), and 12 aged 35 - 56 years (old DS patients, O-DS), underwent qEEG and a battery of neuropsychological tests. In comparison with age-matched controls, qEEG was abnormal in 35 (77%) DS patients, 24 Y-DS (72.7%) and 11 O-DS (91.6%). The prevalence of EEG abnormalities increased with the severity of mental retardation: qEEG was abnormal in 72% of 22 mildly, in 75% of 8 moderately, in 90% of Il severely mentally retarded and 100% of 4 demented O-DS. Band powers, and particularly theta power, differentiate the DS group well from controls, whereas the alpha peak is a better descriptor of aging and cognitive decline.