Early-stage right temporal lobe variant of frontotemporal dementia: 3 years of follow-up observations.

The right temporal lobe variant of frontotemporal dementia (FTD) is an uncommon progressive neurodegenerative disorder. We present the case of a 77-year-old right-handed man who presented with altered behaviour and problems with interpersonal relationships. He had no decline in cognitive function but brain perfusion single-photon emission CT demonstrated distinct hypoperfusion in the right temporal pole. At 2-year follow-up, he could not recognise his wife's relatives; and at 3-year follow-up, he had semantic aphasia. Decreased brain perfusion extended from the right temporal lobe into the contralateral temporal and both frontal lobes. These findings suggest that the right temporal lobe variant of FTD should be considered in elderly patients with altered behaviour and problems with interpersonal relationships, even if dementia is not suspected. The right anterior temporal lobe may play a key role in the onset of the early symptoms of this disease.