Frontotemporal dementia refers to a group of dementias characterised pathologically by degeneration of the frontal and temporal lobes at post-mortem. They are clinically and pathologically diverse. The most common histological findings at autopsy are intracellular inclusions of either hyperphosphorylated tau protein or TDP43.
- Up to 25% of cases are inherited
- Inheritance: AD
- Age of onset: <65
- Prevalence: 15 / 100,000 in 45 – 64 year olds
Early FTD usually presents with an isolated cognitive deficit.
Behavioural variant: presents with progressive behavioural change. Key features include:
- Compulsive behaviour
Primary progressive aphasia: presents with progressive aphasia with relative sparing of other cognitive domains. There are 3 subtypes:
- Nonfluent: speech is stuttering, comprehension relatively spared
- Semantic: impaired comprehension of concepts and naming
- Logopaenic: impaired word-finding, slow speech
- There is a significant overlap between behavioural-variant FTD and ALS. Many patients develop an ALS-like clinical syndrome.
The aim of investigations is to exclude reversible causes for dementia.
- Bloods: FBC, U&E, LFT, HIV, B12, TFTs, Calcium
- MRI: to exclude a structural frontal lesion
Definitive diagnosis, as with all dementias, is based on post-mortem biopsy findings.
- No effective disease-modifying therapy is available
- Treatment is symptomatic and supportive