FTD includes a group of disorders that have the following characteristics:
- Onset between ages 45 and 60
- Major involvement of the frontal lobes or related deep structures of the brain
Common symptoms include:
- Personality change, often with loss of tact, disinhibition, apathy and loss of empathy
- Language changes with difficulty speaking or understanding speech
The brain changes of FTD usually include accumulation of one of two toxic proteins:
The major differences between AD and FTD that favor the diagnosis of FTD in a person with progressive cognitive changes include:
- Earlier age of onset
- More severe personality changes
- Less memory loss
Brain scanning and CSF (cerebrospinal fluid) can be helpful in differentiating FTD from AD. In FTD:
- MRI shows more marked frontal lobe and temporal lobe atrophy.
- FDG PET shows marked frontal lobe or temporal lobe hypometabolism.
- CSF does not show the reduced amyloid levels characteristic of AD.
- Mutation tests can identify some patients with specific genetic causes of AD or FTD.
These three images show a routine T1-weighted MRI sequence from a normal subject. Within the brain, the white matter appears slightly brighter than the grey matter, or cortex. Regions containing cerebrospinal fluid (CSF) appear darker. The grey matter surrounds the brain's periphery and extends inwardly at the sulci. Notice that the brain's folds are tight, with little space between them. Specifically, there is not much space within the sulci. Similarly, the ventricles in the middle of the brain are relatively small, and hard to visualize.
These three images also show imaging from a patient with frontotemporal dementia. The left and right images are from a routine T1-weighted MRI sequence, showing prominence of the sulci greatest anteriorly, around the supraorbital frontal lobes, and around the anterior temporal lobes. There is a relative lack of corresponding volume loss more posteriorly, for example in the parietal lobes, as is often seen with Alzheimer's disease. The middle image is from an FDG-PET examination, which measures the brain's metabolism. Using the colorized "heat" scale, where red shows the brain's normal high metabolism, and green-blue shows abnormally low metabolism, you can see strikingly reduced metabolism mainly confined to the frontal lobes.
- There are no approved treatments for FTD
- There are clinical trials of promising new therapies for FTD