The diagnostic utility of EEG in early-onset dementia: a systematic review of the literature with narrative analysis
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Early-onset dementia (EOD) is characterized by functionally impairing deterioration in memory, language, personality or visuospatial skills emerging under the age of 65. Cerebral functioning can be assessed by visual electroencephalography (EEG) interpretation. The aim of this systematic review is to evaluate the diagnostic utility of visual EEG in EOD focusing on Alzheimer’s disease (AD), vascular dementia (VAD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD). Medline, Embase, Scopus, Web of Knowledge, and Google Scholar were systematically searched for studies where EEGs were included in the diagnostic evaluation of patients with dementia under the age of 65. Each paper was quality assessed and the results grouped according to dementia cause with a narrative summary. 4,157 papers were screened, 12 studies met the eligibility criteria with a total of 965 patients. An abnormal EEG was common to all causes of EOD. EEG abnormalities are more severe in early-onset AD patients. EEG severity grade is independent of disease duration. Slow wave activity is common to all dementias, but is most prominent in DLB. Frontal intermittent rhythmic delta activity could be considered as supportive for the diagnosis of DLB as can a Grand Total EEG score of over 9.5. EEG is usually normal in FTD. Focal changes can be seen in advanced VAD. Studies employed small patient groups, varying diagnostic criteria, and only a minority of patient diagnoses was pathologically confirmed. EEG may be useful as an adjunct in the diagnosis of DLB and AD. Further prospective well-powered studies are required to investigate diagnostic utility more robustly.
KeywordsElectroencephalography Early-onset dementia Alzheimer’s disease Lewy body dementia Vascular dementia Frontotemporal dementia
Suvankar Pal is funded by an award from NHS Research Scotland.
Conflict of interest
- American Psychiatric Association (2000) Diagnostic and statistical manual of mental disorders, 4 text revision (DSM-IV-TR) edn. American Psychiatric Association, WashingtonGoogle Scholar
- Jelic V (2005) EEG in dementia, review of the past, view into the future. In: Sarbadhikari SN (ed) Depression and dementia: progress in brain research, clinical functioning and future trends. Nova Publisher, New York, pp 245–304Google Scholar
- Kowalski JW, Gawel M, Pfeffer A, Barcikowska M (2001) The diagnostic value of EEG in Alzheimer disease: correlation with the severity of mental impairment. Clin Neurophysiol 18(6):570–575Google Scholar
- McKhann G, Drachman D, Folstein M, Katzman R, Price D, Stadlan EM (1984) Clinical diagnosis of Alzheimer’s disease: report of the NINCDS-ADRDA work group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s disease. Neurology 34(7):939–944PubMedCrossRefGoogle Scholar
- Shucholeiki R (2012) Normal EEG waveforms, Medscape reference. http://emedicine.medscape.com/article/1139332-overview#showall. Accessed 26 September 2012 (last updated 28 March 2012)