Frontal temporal dementia: dissecting the aetiology and pathogenesis.

Abstract
Satisfactory classification of frontotemporal dementias (FTD) has always been difficult with historical schemes being based on clinical symptoms and on pathology (reviewed, Kertesz, 2005) and more recent proposals focused on genetics (Foster et al., 1997). Concordance between these schemes is imperfect and the situation further complicated by the growing realization that there is a clinical, pathological and aetiological overlap between amyotrophic lateral sclerosis (ALS) and FTD.