The process of aging produces certain changes in the electroencephalogram (EEG).2,4,8,15 Some of these changes can be considered within the realm of normal variation; others must be considered abnormal.
During middle life, EEG activity becomes relatively faster, with a gradual slowing after this period into the years of senility.8 Focal aberrations of the temporal area, as well as diffuse abnormality after the age of 60, may occur.4 Vascular lesions which cause infarcts or ischemic changes, especially on the surface of the cortex in persons who develop overt cerebrovascular disease with objective neurological findings, will produce focal or generalized EEG changes which often coincide with clinical findings.2,4,7,10,14,15 Changes in the brain substance which occur in diseases associated with aging manifest themselves unpredictably on EEG, however. In Alzheimer's disease (presenile psychosis with generalized cerebral atrophy), diffuse changes in EEG appear, but in Pick's disease (focal cerebral atrophy),
ROSSEN R, SIMONSON E, BAKER J. Electroencephalograms During Hypoxia in Healthy MenResponse Characteristic for Normal Aging. Arch Neurol. 1961;5(6):648–654. doi:10.1001/archneur.1961.00450180070008