No abstract

Hippocampal atrophy detected by volumetric MRI is a sensitive feature of early Alzheimer's disease (AD), but there are no studies evaluating hippocampal atrophy by MR volumetry in other dementing diseases. We therefore compared hippocampal volumes in a total of 113 subjects: 50 patients with mild to moderate AD, 9 patients with vascular dementia (VaD), 12 patients with idiopathic Parkinson's disease (PD) without dementia, 8 patients with PD and dementia (PDD), and 34 elderly control subjects. Thin, coronal, contiguous images were obtained by a 1.5-T MR imager. All patient groups had significantly smaller volumes of the hippocampus compared with the control group. In the PDD group, the absolute volumes were even smaller than in the AD group. In the PD group, the volumes were diminished to a lesser but significant extent. The volumes in the VaD group varied: of nine patients, two had no atrophy, three had unilateral, and four had bilateral atrophy. We postulate that hippocampal atrophy does not seem to be a specific phenomenon of dementia in AD but also occurs in VaD and PDD, and even in PD when no dementia is present. However, coexistence of AD pathology in our PD and VaD patients cannot be ruled out. Further studies with access to neuropathologic data are needed.

No abstract

This quantitative MRI study provides support for a possible association between structural and biochemical substrates and severe drug-resistant major depression.

Age-associated memory impairment (AAMI) is a common but disputed entity. It is unclear whether AAMI is a phenomenon of normal aging or an early sign of Alzheimer's disease. The present study aimed to identify possible structural abnormalities in the medial temporal lobe of AAMI subjects. We measured volumes of the hippocampus and amygdala by MRI in 16 AAMI subjects and in 16 age- and sex-matched controls and correlated the volumes with subjects' performance on two visual memory tasks (the Benton and the Heaton visual retention tests) and on a verbal memory task (the Buschke-Fuld Selective Reminding Test). The mean hippocampal and amygdaloid volumes normalized for brain size per se did not differ between the two study groups. In controls, but not in AAMI subjects, the right hippocampus was larger than the left. Accordingly, the volumetric asymmetry between the right and left hippocampi was smaller in AAMI subjects than in controls (Student's t test, p < 0.05). The volume of the right hippocampus (r = 0.37, n = 32, p < 0.05) and the magnitude of the asymmetry between the right and left hippocampi (r = 0.38, n = 32, p < 0.05) correlated with total score on the Benton test. We also found significant correlations between the amygdaloid volumes and the performance on visual memory tests but not with score on the verbal memory test.(ABSTRACT TRUNCATED AT 250 WORDS)

We studied the usefulness of measuring volumes of the hippocampus, amygdala and frontal lobes with coronal magnetic resonance imaging (MRI) scans in the diagnosis of early Alzheimer's disease (AD). We examined 32 patients diagnosed according to the NINCDS-ADRDA criteria of probable AD and 16 age-matched healthy cognitively normal controls. The AD patients had mild dementia with a mean score of 22.8 in the Mini-Mental Status Examination (MMSE). We used a 1.5 T magnetic resonance imager and normalized the volumes for brain area. The AD patients had significantly smaller volumes of the right and the left hippocampus (-38%) (ANOVA, p < 0.0001) and the left frontal lobe (-16%, p < 0.05) compared to controls. The reductions in volumes of the right frontal lobe (-13%), the right amygdala (-14%) or the left amygdala (-18%) were not statistically significant. In the discriminant function analysis which included the volumes of the hippocampus, amygdala, and the frontal lobes and age, the volumes of the left and right hippocampus, the left and right frontal lobe, and the right amygdala entered the model and we could correctly classify 92% of the subjects into AD and control groups (Chi-square 42.6, df 5, p < 0.001). By using the volumes of the hippocampus, the frontal lobes or the amygdala on their alone, the correct classification was achieved in 88%, 65% and 58% of the subjects, respectively. In addition, in AD patients the volumes of the left hippocampus correlated significantly with the MMSE score and with immediate and delayed verbal memory; the smaller the volume the more impaired was their performance. Our data indicate that measurements of volumes of the hippocampus might be useful in diagnosis of early AD.

No abstract

In patients with cryptogenic epilepsy, recurrent seizures may cause damage to the hippocampus throughout the lifetime of the patient.