Quantitative electroencephalography in mild cognitive impairment: longitudinal changes and possible prediction of Alzheimer’s disease

The present study evaluated the clinical course of patients with mild cognitive impairment (MCI), the pattern of electroencephalography (EEG) changes following cognitive deterioration, as well as the potential of neurophysiological measures in predicting dementia. Twenty-seven subjects with MCI were followed for a mean follow up period of 21 months. Fourteen subjects (52%) progressed (P MCI) to clinically manifest Alzheimer's disease (AD), and 13 (48%) remained stable (S MCI). The two MCI subgroups did not differ in baseline EEG measures between each other and the healthy controls (n = 16), but had significantly lower theta relative power at left temporal, temporo-occipital, centro-parietal, and right temporo-occipital derivation when compared to the reference AD group (n = 15). The P MCI baseline alpha band temporo-parietal coherence, alpha relative power values at left temporal and temporo-occipital derivations, theta relative power values at frontal derivations, and the mean frequency at centro-parietal and temporo-occipital derivations overlapped with those for AD and control groups. After the follow-up, the P MCI patients had significantly higher theta relative power and lower beta relative power and mean frequency at the temporal and temporo-occipital derivations. A logistic regression model of baseline EEG values adjusted for baseline Mini-Mental Test Examination showed that the important predictors were alpha and theta relative power and mean frequency from left temporo-occipital derivation (T5-O1), which classified 85% of MCI subjects correctly.

[1]  L. Berg,et al.  Frequency analysis of the resting awake EEG in mild senile dementia of Alzheimer type. , 1983, Electroencephalography and clinical neurophysiology.

[2]  H. Moldofsky,et al.  Genetic dependence of the electroencephalogram bispectrum. , 1985, Electroencephalography and clinical neurophysiology.

[3]  B. Reisberg,et al.  A Two-Year Longitudinal Study of Cognitive Function in Normal Aging and Alzheimer's Disease , 1993, Journal of geriatric psychiatry and neurology.

[4]  M. Folstein,et al.  Clinical diagnosis of Alzheimer's disease , 1984, Neurology.

[5]  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.

[6]  O Almkvist,et al.  Quantitative electroencephalography power and coherence in Alzheimer's disease and mild cognitive impairment. , 1996, Dementia.

[7]  B W Ongerboer de Visser,et al.  Quantitative spectral electroencephalography in predicting survival in patients with early Alzheimer disease. , 1998, Archives of neurology.

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

[9]  B. Winblad,et al.  Mild cognitive impairment--an early stage of Alzheimer's disease? , 1998, Journal of neural transmission. Supplementum.

[10]  D. Kleinbaum,et al.  Applied Regression Analysis and Other Multivariate Methods , 1978 .

[11]  D Liberati,et al.  EEG coherence in Alzheimer's disease. , 1998, Electroencephalography and clinical neurophysiology.

[12]  H Merskey,et al.  The electroencephalogram in Alzheimer-type dementia. A sequential study correlating the electroencephalogram with psychometric and quantitative pathologic data. , 1987, Archives of neurology.

[13]  T Gasser,et al.  Quantitative EEG analysis in early onset Alzheimer's disease: a controlled study. , 1993, Electroencephalography and clinical neurophysiology.

[14]  I Rosén,et al.  Postural hypotension and EEG variables predict cognitive decline: results from a 5-year follow-up of healthy elderly women. , 1997, Dementia and geriatric cognitive disorders.

[15]  S. Folstein,et al.  "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician. , 1975, Journal of psychiatric research.

[16]  B. Reisberg,et al.  Mild cognitive impairment in the elderly , 1991, Neurology.

[17]  Ian A. Cook,et al.  Reduced EEG coherence in dementia: State or trait marker? , 1994, Biological Psychiatry.

[18]  E. R. John,et al.  Quantitative EEG correlates of cognitive deterioration in the elderly , 1994, Neurobiology of Aging.

[19]  T. Gasser,et al.  EEG coherence in Alzheimer disease. , 1994, Electroencephalography and clinical neurophysiology.

[20]  M Doppelmayr,et al.  Brain oscillations and human memory: EEG correlates in the upper alpha and theta band , 1997, Neuroscience Letters.

[21]  B. Crosson,et al.  Story and list recall tests as measures of verbal memory in a head-injured sample. , 1989 .

[22]  D. Schaid,et al.  Apolipoprotein E status as a predictor of the development of Alzheimer's disease in memory-impaired individuals. , 1995, JAMA.

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

[24]  T Gasser,et al.  Quantitative EEG analysis in early onset Alzheimer's disease: correlations with severity, clinical characteristics, visual EEG and CCT. , 1994, Electroencephalography and clinical neurophysiology.

[25]  F. Duffy,et al.  Temporoparietal electrophysiological differences characterize patients with Alzheimer's disease: a split-half replication study. , 1995, Cerebral cortex.

[26]  M. Corner,et al.  Individual differences in the human electroencephalogram during quiet wakefulness. , 1979, Electroencephalography and clinical neurophysiology.

[27]  D. Kleinbaum,et al.  Applied regression analysis and other multivariable methods, 3rd ed. , 1998 .

[28]  Ove Almkvist,et al.  Diagnostic accuracies of quantitative EEG and PET in mild Alzheimer's disease , 1999 .

[29]  C. Stern,et al.  EEG coherence in men with AIDS: association with subcortical metabolic activity. , 1993, The Journal of neuropsychiatry and clinical neurosciences.

[30]  P. S. St George-Hyslop,et al.  Prediction of probable Alzheimer's disease in memory-impaired patients , 1996, Neurology.

[31]  D O Walter,et al.  Regional differences in brain electrical activity in dementia: use of spectral power and spectral ratio measures. , 1993, Electroencephalography and clinical neurophysiology.

[32]  F H Duffy,et al.  Brain electrical activity in patients with presenile and senile dementia of the Alzheimer type , 1984, Annals of neurology.

[33]  A. Burns Clinical diagnosis of Alzheimer's disease , 1991 .

[34]  H. Soininen,et al.  Aging and spectral analysis of EEG in normal subjects: a link to memory and CSF AChE , 1992, Acta neurologica Scandinavica.

[35]  Ove Almkvist,et al.  Cognitive predictors of incident Alzheimer's disease: a prospective longitudinal study. , 1997, Neuropsychology.

[36]  H. Soininen,et al.  Different patterns of cognitive decline related to normal or deteriorating EEG in a 3‐year follow‐up study of patients with Alzheimer's disease , 1991, Neurology.

[37]  K. Marder,et al.  Neuropsychological detection and characterization of preclinical Alzheimer's disease , 1995, Neurology.

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