Relationships between 99mTc-HMPAO ceraspect and quantitative EEG observations in Alzheimer's disease

Nineteen patients affected with probable Alzheimer's disease (AD) underwent quantitative electroencephalography (qEEG) and semiquantitative regional cerebral blood flow (rCBF) measurement by 99mTc-HMPAO (hexamethyl-propylene amine-oxine) SPECT by a high resolution device (CERASPECT). Perfusional and EEG data were correlated with one another and with the severity of disease, as expressed by the mini mental state examination (MMSE), in a posterior temporoparietal region of interest (ROI) in either of the hemispheres. Moreover, qEEG was also correlated with rCBF in a thalamic and a hippocampal ROI. Both qEEG and rCBF data were significantly correlated to MMSE, especially in the left hemisphere. The qEEG and rCBF results were correlated in the temporoparietal ROI, mainly in the left one, whereas no correlation was found between thalamic ROI and qEEG and only the right hippocampal ROI was slightly related to qEEG. Both techniques are confirmed to be reliable tools in assessing brain failure in AD, and qEEG may be conveniently employed where SPECT is unavailable. Staging a given patient in respect with the course of the disease by means of a multiple neurophysiological approach may overcome the limitations of individual techniques, which appears to be particularly relevant for the evaluation of the impact of eventual future effective treatment.