EEG spectral analysis in delirium.

Abstract

SUMMARY Spectral analysis of EEG was conducted for 51 elderly delirious patients meeting the Diagnostic and Statistical Manual of Mental Disorders III (DSM-III) criteria and for 19 controls. As a whole group, and also when subdivided according to the type of delirium, severity of cognitive decline or the type ofcentral nervous system disease, delirious patients showed significant reductions of alpha percentage, increased theta and delta activity and slowing of the peak and mean frequencies and these changes were also obvious in individual recordings. The alpha percentage and various ratio parameters correlated significantly with Mini Mental State score, and delta percentage and mean frequency with the lengths of delirium and hospitalisation. The results indicate an association between spectral EEG changes and severity of cognitive deterioration in delirium.Delirium is an organic mental disorder characterised by disorganisation of mental functioning due to widespread, temporary derangement of cerebral metabolism appearing symptomatically during the course of an underlying physical illness."-3 It features concurrent disorders of attention, perception, thinking, memory, psychomotor behaviour, and the sleepwaking cycle with fluctuations in depth, and often with delusions or hallucinations.4 The aetiology of delirium is almost invariably multifactorial, often including a predisposing central nervous system (CNS) disease and one or more possible causative factors.56In demented patients, a number of studies with routine and quantitative EEG have shown slowing of the mean occipital frequency and increased activity in the lower frequency bands with correlation to the degree of dementia, especially in Alzheimer's disease.7'2 In delirious patients, previous studies using routine EEG have also shown an increase ofslow wave activity and slowing and disruption of the normal alpha rhythm.5"3'4 As information concerning the possible correlations between the clinical symptoms (such as severity ofcognitive deterioration and type of delirium) and EEG changes in delirious patients is limited, we decided to study the spectral EEG changes in delirious elderly patients meeting the DSM-III Address for reprint requests: Hannu Koponen, MD,

A longitudinal study of motor subtypes in delirium: Relationship with other phenomenology, etiology, medication exposure and prognosis

“…In contrast, all cognitive and thought process abnormalities, and key diagnostic features were comparable across clinical subtypes. Therefore, our study using detailed assessment of a range of cognitive domains on the DRS-R98 and CTD, concurs with previous cross-sectional studies in elderly medical and consultation-liaison populations that found comparable cognitive and EEG abnormalities across motor subtypes of delirium [15,[35][36][37]. Overall, phenomenological studies suggest that cognitive and contextual items (i.e.…”

EEG changes and serum anticholinergic activity measured in patients with delirium in the intensive care unit

“…These EEG results confirm previous findings reported in standard and spectral EEG in delirious patients [20][21][22][23]. However, EEG analysis is a relatively extensive and time-consuming method for use in daily clinical practice, and it would therefore be helpful to have another objective parameter for detecting delirium when the clinical diagnosis is unclear.…”

“…In the present study, patients receiving long-term medication for psychiatric and neurological disorders not included. Furthermore, to compare EEGs of ICU patients under the same sedative conditions, centrally acting anticholinergic drugs such as neuroleptics, benzodiazepines, and barbiturates, which are often administered during anaesthesia and on the ICU [21,33,34] and which have been associated with high SAA levels and delirium [35], were excluded from the present analysis (with the exception of piritramide). In addition, other endogenous sources of SAA have been postulated [13,24].…”

Early postoperative delirium after open-heart cardiac surgery is associated with decreased bispectral EEG and increased cortisol and interleukin-6

“…Indeed, in agreement with previous studies [14], a lower RASS was associated with a lower BIS index in this study. The lower BIS EEG in delirious patients obtained in our present study confirm previous findings using standard and spectral EEG [11,26,27], our previous results using a 16-channel EEG [12], and also in part the results of Ely et al [14] using a monolateral BIS EEG technique.…”