ATROPHY OF HIPPOCAMPUS IN PATIENTS WITH ALZHEIMERS-DISEASE AND OTHER DISEASES WITH MEMORY IMPAIRMENT

In clinical practice, Alzheimer's disease (AD), multi-infarct Dementia (MID) and depression are often difficult to differentiate and may coe xist. This study reports the findings of CT and MRI focused on hippoca mpal atrophy (HA). Quantitative volumetric MRI measurements of the hip pocampus showed a reduced volume in AD patients compared to normal con trols with no overlap. CT studies reported a significant widening of t he hippocampal fissure in AD patients. Because volumetric measurements are not available for routine examinations, so far we are required to use the finding of hippocampal lucency in CT and dilatation of the di rectly visible hippocampal fissure in coronal MRI scans as criteria fo r HA. These findings were visually classified on a 4-point scale by 2 neuroradiologists, who had no knowledge of the clinical diagnosis. The examinations of 80 patients (42 with AD, 22 with major depression, 3 with MID, 6 classified as age-associated memory impairment (AAMI) and 8 'normals' with only subjective memory impairment) showed that the HA stronlgy supports the diagnosis of AD, by correctly identifying 95% o f the AD patients and 47.8% of the patients without AD. These results suggest that CT and MRI examinations of the hippocampus are capable of demonstrating HA in clinical practice, which is strongly correlated w ith the diagnosis of AD.