Loss of high-frequency brain electrical response to thiopental administration in Alzheimer's-type dementia.
Abnormal brain regions generate proportionately less high-frequency (beta) activity than nonpathological regions, a phenomenon accentuated by barbiturate administration. Using quantitative electroencephalography we examined power in the 20- to 28-Hz band in patients with dementia of the Alzheimer's type (DAT), vascular dementia (VaD), and normal elderly controls (CON) following an IV bolus of thiopental (0.5 mg/kg). Compared to both CON and VaD subjects, DAT subjects showed a marked loss of beta power elicited across the cortex, with largest differences noted in the frontal region. Losses were most significant for the peak response recorded at 30 to 90 s postinjection and persisted during the 5-minute follow-up period. We hypothesize that differences in this electrocerebral response reflect differences in the underlying neuropathology of DAT and VaD subjects. A thiopental challenge may be well suited for the in vivo assessment of brain function in dementias characterized by prominent cortical pathology.
Holschneider
D P
DP
Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles School of Medicine, USA.
Leuchter
A F
AF
Uijtdehaage
S H
SH
Abrams
M
M
Rosenberg-Thompson
S
S
D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D015140:Dementia, Vascular / Q000503:physiopathology; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D013874:Thiopental / Q000494:pharmacology*
D006993:Hypnotics and Sedatives; D013874:Thiopental