ABSTRACT
99m-technetium-hexamethylpropylene-amineoxine (99m-Tc-HMPAO) single-photon-emission-computer-tomography (SPECT)-scans and spectral analyzed electroencephalogram (EEGs) of 20 patients with Alzheimer's disease (AD) were studied. A significant correlation was found between the temporoparietal-cerebellar-ratio (TP/C-ratio) of the SPECT-scan and the peak frequencies of leads T3-T5, C3-P3, and C4-P4 of the EEG. In addition a significant negative correlation between the TP/C-ratio and the theta/alpha-ratio (t/a-ratio) of leads T3-T5, T4-T6, C3-P3, and C4-P4 was demonstrated. Our study demonstrates that slowing of the EEG parallels a decrease in blood flow in the temporoparietal regions in AD-patients. Both findings could be parallel phenomena of regional hypometabolism.
Subject(s)
Alzheimer Disease/diagnosis , Electroencephalography , Organotechnetium Compounds , Oximes , Tomography, Emission-Computed, Single-Photon , Adult , Aged , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/physiopathology , Electroencephalography/instrumentation , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Occipital Lobe/diagnostic imaging , Occipital Lobe/physiopathology , Parietal Lobe/diagnostic imaging , Parietal Lobe/physiopathology , Signal Processing, Computer-Assisted , Technetium Tc 99m Exametazime , Temporal Lobe/diagnostic imaging , Temporal Lobe/physiopathologyABSTRACT
The influence of sedative doses of propofol or nitrous oxide on the electroencephalogram was studied in 11 mentally handicapped patients with treated epilepsy undergoing dental procedures. At one session, propofol was titrated to achieve conscious sedation. The mean (+/- SD) dose requirements were 5.5 +/- 1.1 mg.kg-1.h-1. In six patients, the electroencephalogram was unchanged during propofol administration. In three patients, there was a decrease in epileptic activity, and in two patients, paroxysmal discharges disappeared. At another session, nitrous oxide was administered by nasal mask. The mean (+/- SD) concentration of nitrous oxide needed was 43.6% +/- 4.8%. The electroencephalogram did not change in nine patients, whereas in two patients epileptic activity decreased. There were no clinical epileptoid or other adverse manifestations during any treatment or up to 48 h thereafter. The results of the present study suggest that propofol or nitrous oxide can be administered in subanesthetic doses for conscious sedation in mentally handicapped patients with treated epilepsy.
