Objectives-Memory impairment is not only the earliest clinical symptom but a central and prominent feature throughout the course of Alzheimer's disease. Alzheimer related pathological alterations in the medial temporal structures may account for the memory impairments in patients with Alzheimer's disease. The aim of this study was to elucidate the role of the medial temporal structures in memory impairment caused by Alzheimer's disease. Methods-Using high resolution MRI and a semiautomated image analysis technique, volumes of the medial temporal structures (amygdaloid complex, hippocampal formation, subiculum, and parahippocampal gyrus) were measured, and correlations between atrophy of each structure and memory dysfunction in patients with Alzheimer's disease were examined. Results-Patients with Alzheimer's disease showed poor performance on verbal and non-verbal memory tests, and MRI volumetry showed a significant volume reduction of the medial temporal lobe structures. Volumes of the amygdaloid complex and of the subiculum correlated with memory performance. Stepwise regression analyses disclosed that the volume of the right amygdaloid complex specifically predicted visual memory function and to some extent verbal memory function, and that the volume of the left subiculum specifically predicted verbal memory function. Atrophy of the hippocampus did not predict severity of memory impairment. Conclusions-The presence of perihippocampal damage involving the amygdala proper, its surrounding cortex, and the subiculum further increased the severity of memory impairment attributable to hippocampal damage in Alzheimer's disease.

Objectives-Many clinical and biological factors have been reported to be associated with the presence of psychosis in patients with Alzheimer's disease, although the associations were variable. The aim of this study was to clarify factors associated with the presence of psychosis in patients with Alzheimer's disease. Methods-Psychiatric functioning was studied in 228 patients with Alzheimer's disease based on the results of the behavioural pathology in Alzheimer's disease rating scale or the neuropsychiatric inventory. The eVects of sex, education level, age, duration of illness, cognitive function, and apolipoprotein E genotype were investigated for dichotomous psychotic status with a multiple logistic regression analysis. Results-Of the 228 patients with Alzheimer's disease, 118 (51.8%) showed evidence of delusions or hallucinations. Of these, 94 had delusions only, three had hallucinations only, and 21 had both. Older age, female sex, longer duration of illness, and more severe cognitive impairment were the factors independently associated with the presence of psychosis. The presence of psychosis was not significantly related to either educational level or apolipoprotein E genotype. Conclusions-Age, sex, and severity of illness were independent factors associated with the presence of psychosis in patients with Alzheimer's disease. The reason why some patients with Alzheimer's disease develop psychosis remains unclear. There may be distinctive subtypes of Alzheimer's disease or the presence of individual factors which aVect the development of psychosis. (J Neurol Neurosurg Psychiatry 1998;64:648-652)

The disproportionately severe visuoperceptual, visuoconstructive, and visuospatial dysfunction and the disproportionately mild memory impairment in DLB compared with AD, which likely reflect the distribution of the pathologic changes in DLB, can help to differentiate DLB from AD.

Fear reinforces memory retention of an episode in subjects with Alzheimer's disease but does not enhance retention of its context, despite repeated exposure to the information.