Search tips
Search criteria 


Logo of jnnpsycJournal of Neurology, Neurosurgery and PsychiatryVisit this articleSubmit a manuscriptReceive email alertsContact usBMJ
J Neurol Neurosurg Psychiatry. 1993 February; 56(2): 153–158.
PMCID: PMC1014814

Conventional and quantitative EEG in the diagnosis of delirium among the elderly.


This study was performed to determine whether an admission quantitative EEG (QEEG) could assist in the differential diagnosis of encephalopathy among a group of elderly subjects with delirium, dementia, and delirium coexistent with dementia. Thirty four subjects from 57 to 93 years had standard 17-channel EEG and quantitative EEG studies, using a linked-ear reference. EEGs were independently rated by two electroencephalographers blind to clinical diagnosis, using conventional criteria to assess the degree of encephalopathy. Brain maps were scored by a scale developed by the authors. Numerical data examined included mean posterior dominant frequency, absolute and relative power in the delta, theta and alpha bands, and slow-wave ratios. The grouping of experimental subjects was by the discharge diagnosis, made using DSM-III-R criteria. Stepwise discriminant analysis was performed to determine which EEG and QEEG variables were best able to distinguish cases. Variables which collectively distinguished normal from encephalopathic records were Mini-Mental State Examination scores and relative power in the alpha frequency band. Variables which collectively distinguished delirium from dementia were EEG theta activity, relative power in delta, and brain map rating. The results suggest that cross-sectional QEEG study is potentially useful in the early differential diagnosis of encephalopathy, and that the variables which distinguish normal from encephalopathic patients might differ from the variables which distinguish delirium from dementia.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1021K), or click on a page image below to browse page by page.

Articles from Journal of Neurology, Neurosurgery, and Psychiatry are provided here courtesy of BMJ Group