Argyrophilic grains: A distinct disease or an additive pathology?

Background Argyrophilic grains (AG) are silver-positive spindle-shaped lesions found at postmortem. Their significance is controversial. Objective To determine clinical correlates of AG and MRI patterns of atrophy that could allow premortem recognition of this pathology. Methods Cases with AG were identified from a longitudinal study of aging and dementia. Clinical features were compared between subjects with and without dementia. Voxel-based morphometry (VBM) was used to assess patterns of grey matter atrophy in subjects compared to controls. Whole brain volumes (WBV) were compared across groups. Results Twenty-two cases (14 females; median age at death of 90 years; range: 70–101) with AG were identified. Eight of the 22 were demented. Those with dementia had higher Braak (p = 0.02) and lower Mini-Mental State Examination (MMSE) (p = 0.002). VBM demonstrated hippocampal atrophy in those with dementia (N = 3) but no atrophy in those without (N = 9). There was no difference in WBV between groups. Conclusion AG is a feature of old age commonly occurring in non-demented subjects. In this age group, the presence of AG may reduce the threshold for dementia.