BACKGROUND Hippocampal atrophy on magnetic resonance imaging (MRI) is an early characteristic of Alzheimer's disease. However, hippocampal atrophy may also occur in other dementias, such as frontotemporal lobar degeneration (FTLD). OBJECTIVE To investigate hippocampal atrophy on MRI in FTLD and its three clinical subtypes, in comparison with Alzheimer's disease, using volumetry and a visual r...