Voxel-wise analysis of 18F-fluorodeoxyglucose metabolism in correlation with variations in the presentation of Alzheimer’s disease: a clinician’s guide

Diagnostic imaging can be applied in the management of Alzheimer’s disease as it provides structural and functional information to exclude possible secondary causes and offers additional information, especially in atypical cases of Alzheimer’s disease. The utility of positron emission tomography/computed tomography (PET/CT) can help in the noninvasive diagnosis of Alzheimer’s disease by voxel-wise quantification of cerebral 18F-fluorodeoxyglucose (FDG) metabolism. Methods: This prospective study was conducted among 10 subjects with Alzheimer’s disease and 10 healthy control subjects who underwent neuropsychological testing and 18F-FDG PET/CT scans. Images of the brain were postprocessed using voxel-wise analysis and segmented into 20 regions of interest. The standardized uptake value (SUV)max/SUVmean/standard deviation of SUVmean results were analyzed accordingly and correlated with the subjects’ Montreal cognitive assessment (MoCA) results that were adjusted for age and education level. Results: Hypometabolism at the right parietal lobe significantly correlated with increasing age and lower MoCA scores. Global hypometabolism was observed in subjects who had advanced Alzheimer’s disease but preserved primary somatosensory cortices (S1) region metabolism. Predominance of frontal lobe hypometabolism was a feature of subjects with Alzheimer’s disease having associated depressive symptoms. Conclusions: 18F-FDG PET/CT voxel-wise analysis can be used for quantitative assessment and can assist clinicians in the diagnosis of Alzheimer’s disease and other variations of the disease spectrum

Apolipoprotein E genotypes and behavioural and psychological symptoms of dementia (BPSD) in Malaysian patients with dementia

The aim of this study was to determine the relationships between ApoE genotypes and ‘behavioural and psychological symptoms of dementia’ (BPSD). A cross-sectional study was conducted on 46 outpatients with dementia (aged 60 and above) and their caregivers attending the psychogeriatric clinics at Universiti Kebangsaan Malaysia Medical Centre (UKMMC) and Hospital Kuala Lumpur. Neuropsychiatric Inventory (NPI) was used for the assessment of BPSD. The patients’ blood samples were taken for Apolipoprotein genotyping after consented by the caregivers. There were more female (69.6%) and Chinese (50%) patients with a mean age of 73.7 years. ApoE ε3/ε3 was the most common ApoE allele (60.7%) and mostly found in Chinese patients. ApoE genotype was significantly associated with ethnicity (p=0.03) and marital status (p=0.01). Alzheimer disease was the most common subtype of dementia (41.3%) and the highest carrier of ApoE ε3/ε3 (30.4%). The ApoE ε4/ ε4 scored highest in BPSD median score 44 (17.5 to 90) but the relationships between ApoE genotypes and subtypes of dementia or BPSD scores were not significant (p=0.20; p=0.64). Agitation was the most common symptom, with delusions showing the highest scores on the NPI with no significant association to ApoE 4 allele. In conclusion, there was no significant relationship between ApoE genotypes and severity or types of BPSD in dementia patients