Relationship between both IQ and Mini-Mental State Examination and the regional cerebral glucose metabolism in clinically diagnosed Alzheimer's disease: A PET study

In order to clarify the hypofunction in which brain areas demonstrate a dec line in Intelligence Quotient (IQ), we examined correlations between the IQ and Mini-Mental State Examination (MMSE) and regional cerebral metabolic r ate of glucose (rCMRglc) measured using positron emission tomography (PET) in 26 patients with clinically diagnosed Alzheimer's disease (AD). The MMSE scores and full-scale IQ (FSIQ) showed significant correlations with the r CMRglc in the temporal and parietal lobes on both sides and in the left fro ntal lobe, which were significantly reduced in comparison to those in the n ormal controls, A multiple regression analysis showed only the MMSE score t o predict verbal IQ (VIQ), performance IQ (PIQ) and FSIQ. VIQ was also pred icted by the rCMRglc in the left parietal lobe, while PIQ was predicted by the age at onset. The results suggested MMSE to be an index of dementia sev erity reflected by general intelligence as shown by IQ in AD, and a reducti on in the VIQ can thus be used as an index of the left parietal dysfunction , which is not expressed by MMSE. Copyright (C) 2001 S. Karger AG, Basel.