EEG in successful aging; a 5 year follow-up study from the eighth to ninth decade of life.
Fifteen out of 25 successfully aged individuals completed a 5 year EEG follow-up study from the eighth to ninth decade of life with comprehensive neuropsychological investigation. One subject suffered from stroke and one developed symptoms of dementia during the follow-up. Of 13 subjects who completed the follow-up as being healthy, MRI showed subtle enlargement of ventricles or subarachnoid spaces and mild signal hyperintensities in a few regions in 2 subjects. General cognitive decline was not observed (WAIS-R IQ: 113.4 at entry, 114.3 five years later). There were no EEG dominant frequencies below 8 c-sec and no more background slowing than a few theta waves per 10 sec, either at entry or 5 years later. Intermittent slowing was observed in 9 subjects at entry and in 8 subjects 5 years later. The prevalence of intermittent slowing was suggested to increase with advancing age when compared to previous studies with younger elderly. However, intermittent slowing occurred only a few times in an EEG test and lasted for less than 2 sec. Moreover, the presence of intermittent slowing did not correlate with any neuropsychological decline or any MRI change. This type of intermittent slowing was regarded as non-specific and clinically silent.
Shigeta
M
M
Department of Clinical Neuroscience and Family Medicine, Geriatric Medicine, Huddinge University Hospital, Karolinska Institute, Sweden.
Julin
P
P
Almkvist
O
O
Basun
H
H
Rudberg
U
U
Wahlund
L O
LO
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests