Right versus left temporal lobe semiology in dementia: Lessons from two cases with focal frontotemporal dementia syndromes.

Focal atrophy of the left anterior temporal lobe has been associated with the semantic type of primary progressive aphasia evolving to semantic dementia. In contrast, focal atrophy of the right temporal lobe has more recently been described as a controverse entity reported as the right temporal variant of FTD. We describe two cases of FTD dementia syndromes: in Case 1, atrophy of the right temporal lobe led to significant behavioural impairment and difficulties in recognizing known people. In Case 2, atrophy of the left temporal lobe was associated with severe aggressive, ritualistic behaviour and aphasia.