Preliminary application of processed electroencephalogram monitoring to differentiate senile dementia from depression

Abstract

Background: It is difficult, but important, to distinguish between dementia and depression in old age because senile depression has atypical symptoms, including cognitive impairment and memory disorder. Now brain computed tomography, magnetic resonance imaging, single photon emission computed tomography, and positron emission tomography can be used to differentiate between these two conditions. However, these methods are expensive and not always available. In the present case series, we assessed the potential of monitoring the bispectral index to distinguish between dementia and depression. Methods: A processed electroencephalogram monitor (bispectral index (BSI) monitor) was used to assess brain activity during relaxed wakefulness in 12 participants (seven with Alzheimer's disease (AD), three with depression, and two healthy volunteers). Each recording lasted 5 min and four variables (i.e. BSI, 95% spectral edge frequency, electromyogram activity, and signal quality index) were monitored. Results: The BSI was significantly smaller in AD patients than in patients with depression (P < 0.05) and the 95% spectral edge frequency tended to be lower in AD patients than in patients with depression (P = 0.26). Slow waves were found in patients with AD and beta waves were predominant in patients with depression and healthy volunteers. Conclusion: In conclusion, the BSI and 95% spectral edge frequency were slightly smaller in dementia patients than in patients with depression. Paroxysmal slow waves may account for the low bispectral index. Thus, BSI monitoring may become a useful tool with which to distinguish AD from depression.

Elderly depression and diffusion tensor imaging

“…In the clinical setting, depression in the elderly needs to be differentially diagnosis from neurodegenerative diseases causing dementia, 3 including Alzheimer's disease, 4 diffuse Lewy body disease, 5 frontotemporal dementia, 6 and Parkinson's disease 7 , but this is sometimes difficult, even with neuropsychological, 8,9 biochemical, 10–12 electrophysiological, 13,14 or brain imaging examinations 15–18 . For dementia patients with depression, effective pharmacological 4 and non‐pharmacological 19–22 interventions are sometimes required to control agitation, irritation, negativism, and violent and suicidal behaviors 11 …”

Frontal shift of posterior alpha activity is correlated with cognitive impairment in early Alzheimer's disease: A magnetoencephalography-beamformer study

“…Alzheimer's disease (AD) is the most common neurodegenerative disorder; it is characterized mainly by cognitive and intellectual deficits. Electroencephalography (EEG) has long been used as a diagnostic tool in AD 1–3 . Several EEG patterns of brain oscillatory activity have been reported in AD, including a slowing and diffusing of the posterior dominant alpha activity, an unclear alpha attenuation after eye opening, and an increase in delta and theta, as well as a decrease in beta and gamma, activities in certain cortical regions 1,2,4 .…”

“…Electroencephalography (EEG) has long been used as a diagnostic tool in AD. [1][2][3] Several EEG patterns of brain oscillatory activity have been reported in AD, including a slowing and diffusing of the posterior dominant alpha activity, an unclear alpha attenuation after eye opening, and an increase in delta and theta, as well as a decrease in beta and gamma, activities in certain cortical regions. 1,2,4 However, in patients with early AD in particular, it is sometimes difficult to visualize these typical EEG findings.…”

Depression in the elderly

“…On the other hand, it should be kept in mind that there are dementia patients showing depressive symptoms as the initial signs of dementia 19 . The differential diagnosis of dementia and depression is sometimes difficult 20–22 and there are reports indicating that electrocardiogram 23 and serum level of amyloid beta‐protein 24 are useful as the differential markers between these conditions.…”