ABSTRACT
References 665
The term frontotemporal lobar degeneration (FTLD) is used here to describe a clinically and pathologically heterogeneous group of non-Alzheimer forms of dementia arising from degeneration of the frontal and temporal lobes. The prototypical, and most common, clinical syndrome is frontotemporal dementia (FTD), manifesting as behavioural and personality changes, involving disinhibition, stereotypy, unsocial acts and language disorder, leading to apathy, mutism and late neurological (frontal release or extrapyramidal) signs (Neary et al., 1998; Neary et al., 2005; Neary et al., 2007). However, the spectrum of illness is wider, involving cases where movement disorder, with relatively mild dementia, is the major disabling feature (Cordes et al., 1992; Wszolek et al., 1992; Lynch et al., 1994) or others with the linguistic disorders of semantic dementia (SD) and progressive non-fluent aphasia (PNFA) (Snowden et al., 1992; Neary et al., 1998; Neary et al., 2005; Neary et al., 2007). FTD can be accompanied by clinical motor neurone disease (MND) in about 10 per cent cases giving the syndrome of frontotemporal dementia with motor neurone disease (FTD1MND) (Neary et al., 1998; Neary et al., 2005; Neary et al., 2007). Onset of illness is usually before 65 years of age, with duration being between six and nine years, though up to 15 years is not uncommon (Neary et al., 1998; Rosso et al., 2003; Neary et al., 2005; Neary et al., 2007).
