BRAIN VOLUMES AND REGIONAL CEREBRAL BLOOD-FLOW IN CARRIERS OF THE SWEDISH ALZHEIMER AMYLOID PROTEIN MUTATION

As a preliminary part of a longitudinal clinical study of carriers of the Swedish amyloid precursor protein (APP) 670/671 mutation, 13 membe rs of a family were investigated with magnetic resonance imaging (MRI) brain volumetry and single photon emission computed tomography (SPECT ) cerebral blood flow (CBF) measurements. Five of the family members w ere mutation carriers, eight were not carriers. Two carriers were youn ger than 40 years of age and had no evidence of cognitive dysfunction or structural or functional brain changes. One carrier with 4 years to expected disease onset showed poor performance in episodic memory tes ts and also slightly low temporal lobe CBF, although there were no cle arly abnormal findings. One carrier with mild Alzheimer disease (AD) h ad no clear structural brain changes, although CBF measurements showed clear reduction of temporal lobe CBE One carrier with severe AD had b oth temporal lobe atrophy and CBF reduction. This indicates that in ca rriers of the APP 670/671 mutation, reduction of regional CBF is more severe than regional atrophy. The clearest change related to developme nt of clinical AD was a reduction of CBF in the basal and lateral temp oral lobes. Further longitudinal studies of these subjects are needed to confirm these preliminary findings, which might provide important d ata regarding early brain changes in AD.