Aging and spectral analysis of EEG in normal subjects: a link to memory and CSF AChE

We studied the effect of aging on EEG spectra recorded from T5–O1 (T6‐O2) derivation. The aging series composed of 52 normal individuals aged 20 to 91 years. Seventy‐nine per cent of visual and 81% of quantitative EEGs were considered normal. The absolute amplitude of delta and theta bands and absolute power of delta band were lower for the oldest group (aged 60 and over) than for the youngest group (aged 20–39 years). Age was inversely related to the amount of delta and theta indicating that the amount of slow activity in quantitative EEG does not increase with age in the context of good health status. Women had more beta activity compared with men. In addition, the amount of beta and alpha bands showed tendency for a reduction with age. Fifteen subjects aged 50 years or older participated in a 2‐year follow‐up including EEG and neuropsychological evaluation. Seven of them deteriorated in learning ability and showed increase in delta activity. In the oldest age group, delta amplitude was positively correlated with intrusion errors in the list learning test and inversely related to acetylcholinesterase activity of the CSF. Thus, a link between the cholinergic system, EEG slowing and memory problems in old age is suggested.

[1]  T. Arendt,et al.  The cholinergic system in aging , 1990, International Journal of Developmental Neuroscience.

[2]  T. Gasser,et al.  Transformations towards the normal distribution of broad band spectral parameters of the EEG. , 1982, Electroencephalography and clinical neurophysiology.

[3]  J. Roubíček.  The Electroencephalogram in the Middle‐Aged and the Elderly , 1977, Journal of the American Geriatrics Society.

[4]  H. Soininen,et al.  EEG findings in senile dementia and normal aging , 1982, Acta neurologica Scandinavica.

[5]  S Giaquinto,et al.  The EEG in the normal elderly: a contribution to the interpretation of aging and dementia. , 1986, Electroencephalography and clinical neurophysiology.

[6]  P. Jäkälä,et al.  Interaction between the alpha2-noradrenergic and muscarinic Systems in the regulation of neocortical high voltage spindles , 1990, Brain Research Bulletin.

[7]  H. Soininen,et al.  Changes in absolute power values of EEG spectra in the follow‐up of Alzheimer's disease , 1991, Acta neurologica Scandinavica.

[8]  M. Nuwer.  Quantitative EEG: II. Frequency Analysis and Topographic Mapping in Clinical Settings , 1988, Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society.

[9]  19 – Topographic EEG Correlates of Cerebral Blood Flow and Oxygen Consumption in Patients with Neuropsychological Disorders , 1986 .

[10]  J. Sirviö,et al.  The effects of THA on medial septal lesion-induced memory defects , 1990, Pharmacology Biochemistry and Behavior.

[11]  D. Ingvar,et al.  Correlation between dominant EEG frequency, cerebral oxygen uptake and blood flow. , 1976, Electroencephalography and clinical neurophysiology.

[12]  M. Matousek,et al.  EEG frequency analysis related to age in normal adults. , 1967, Electroencephalography and clinical neurophysiology.

[13]  R. Reitan.  Validity of the Trail Making Test as an Indicator of Organic Brain Damage , 1958 .

[14]  B. Saletu,et al.  Quantitative EEG: investigation in children with end stage renal disease before and after haemodialysis. , 1986, Clinical EEG.

[15]  H. Soininen,et al.  Longitudinal EEG spectral analysis in early stage of Alzheimer's disease. , 1989, Electroencephalography and clinical neurophysiology.

[16]  N Butters,et al.  Episodic and semantic memory: a comparison of amnesic and demented patients. , 1987, Journal of clinical and experimental neuropsychology.

[17]  M S Buchsbaum,et al.  Topographic EEG changes with normal aging and SDAT. , 1989, Electroencephalography and clinical neurophysiology.

[18]  J. R. Hughes,et al.  The EEG in patients at different ages without organic cerebral disease. , 1977, Electroencephalography and clinical neurophysiology.

[19]  G. Buzsáki,et al.  Electric activity in the neocortex of freely moving young and aged rats , 1988, Neuroscience.

[20]  S. Schalm,et al.  Quantitative EEG analysis and survival in liver disease. , 1985, Electroencephalography and clinical neurophysiology.

[21]  G. Buzsáki,et al.  The cholinergic system and EEG slow waves. , 1991, Electroencephalography and clinical neurophysiology.

[22]  M. Decker.  The effects of aging on hippocampal and cortical projections of the forebrain cholinergic system , 1987, Brain Research Reviews.

[23]  L. Sokoloff.  Effects of Normal Aging on Cerebral Circulation and Energy Metabolism , 1979 .

[24]  D. E. Shearer,et al.  Power spectral analysis and cortical coupling of EEG for young and old normal adults , 1985, Neurobiology of Aging.

[25]  J. Partanen,et al.  The effects of concurrent manipulations of cholinergic and noradrenergic systems on neocortical EEG and spatial learning. , 1990, Behavioral and neural biology.

[26]  Joseph D. Bronzino,et al.  Quantitative Analysis of the EEG - General Concepts and Animal Studies , 1984, IEEE Transactions on Biomedical Engineering.

[27]  W. Obrist.  Electroencephalographic Changes in Normal Aging and Dementia , 1979 .

[28]  P. Riederer,et al.  Alzheimer’s Disease. Epidemiology, Neuropathology, Neurochemistry, and Clinics , 1990, Key Topics in Brain Research.

[29]  R. Katz,et al.  Electroencephalogram in the Septuagenarian: Studies in a Normal Geriatric Population , 1982, Journal of the American Geriatrics Society.

[30]  F H Duffy,et al.  Age‐related differences in brain electrical activity of healthy subjects , 1984, Annals of neurology.

[31]  R. Loewenson,et al.  The electroencephalogram of elderly subjects revisited. , 1983, Electroencephalography and clinical neurophysiology.

[32]  V. Hachinski,et al.  Quantitative electroencephalographic correlates of cognitive decline in normal elderly subjects. , 1990, Archives of neurology.

[33]  E. Busse,et al.  EEG of healthy old persons--a longitudinal study. I. Dominant background activity and occipital rhythm. , 1969, Journal of gerontology.

[34]  Paul D. Coleman,et al.  Neuron numbers and sizes in aging brain: Comparisons of human, monkey, and rodent data , 1988, Neurobiology of Aging.

[35]  H. Soininen,et al.  Quantitative analysis of occipital EEG in different stages of Alzheimer's disease. , 1985, Electroencephalography and clinical neurophysiology.

[36]  M. Storandt,et al.  A longitudinal EEG study of mild senile dementia of Alzheimer type: changes at 1 year and at 2.5 years. , 1985, Electroencephalography and clinical neurophysiology.

[37]  J. Sirviö,et al.  Relationship between the cortical choline acetyltransferase content and EEG delta-power , 1990, Neuroscience Research.

[38]  J. Partanen,et al.  Brain cholinergic enzymes and cortical EEG activity in young and old rats. , 1989, Comparative biochemistry and physiology. C, Comparative pharmacology and toxicology.

[39]  P. Riekkinen,et al.  Regulation of EEG delta activity by the cholinergic nucleus basalis , 1989 .

[40]  R. Katzman.,et al.  Pathological verification of ischemic score in differentiation of dementias , 1980, Annals of neurology.

[41]  R. Katzman.,et al.  Intrusions as a sign of Alzheimer dementia chemical and pathological verification , 1982, Annals of neurology.

[42]  R. Bartus,et al.  The cholinergic hypothesis of geriatric memory dysfunction. , 1982, Science.

[43]  M. Rossor,et al.  Post-Mortem Neurochemical Changes in Alzheimer's Disease Compared With Normal Ageing , 1986, Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques.