Impaired cerebral glucose metabolism and cognitive functioning predict deterioration in mild cognitive impairment

The objective of this study was to assess whether reduced glucose metabolis m (rCMRGlu) and cognitive functioning could predict development of Alzheime r's disease (AD) in subjects with mild cognitive impairment (MCI). Twenty M CI patients underwent baseline and follow-up investigations of rCMRGlu, as measured by PET, and cognitive function measured by neuropsychological test assessments. Subjects were clinically followed up with an average interval of 36.5 months. Two groups were obtained after the second clinical assessm ent. Nine patients were diagnosed as AD and classified as progressive MCI ( P-MCI), whereas 11 patients remained clinically stable and were classified as stable MCI (S-MCI). There were no differences in demographic variables o r baseline MMSE between the two subgroups. Logistic regression indicated th e two variables that most effectively predicted future development of AD we re rCMRGlu from the left temporoparietal area and performance on the block design. These combined measures gave an optimal 90% correct classification rate, whereas only rCMRGlu or neuropsychology alone gave 75% and 65% correc t classification, respectively. Measures of temporoparietal cerebral metabo lism and visuospatial function may aid in predicting the evolution to AD fo r patients with MCI. NeuroReport 12:851-855 (C) 2001 Lippincott Williams & Wilkins.