Outward inspection of the brain in FTLD gives few clues to pathogenesis, but can be a useful index of clinical presentation. Hence, FTD is associated with bilateral atrophy of the frontal and anterior temporal lobes and SD is associated with bitemporal lobe atrophy, oen asymmetric, but usually favouring the le side. PNFA is associated with marked asymmetry, most oen of the le cerebral hemisphere (Neary et al., 2005, 2007). Routine histology has contributed little to our understanding of the disorder, beyond
the early identication of the ‘classic’ inclusion bodies (Pick bodies) and swollen neurones (Pick cells) (Pick, 1892), and the characteristic, though non-specic, features of microvacuolation of outer cortical laminae marking the site of the principal molecular changes (Knopman et al., 1990).