Frontotemporal Dementia is relatively rare, accounting for less than 2% of all cases of dementia in the Canada. Unlike Alzheimer’s disease, which becomes more likely with increasing age, Frontotemporal dementia is less common in individuals over the age of 65, and tends to predominantly affect adults between the age of 45 and 65. Even though Frontotemporal dementia is relatively rare, it is the second most common form of dementia in younger adults (Alzheimer’s Disease is the most common).
A number of different changes have been identified in the brains of individuals with Frontotemporal dementia, including the formation of Pick Cells (abnormal deposits of protein which affect the function of brain cells) and cellular changes similar to those seen in Motor Neurone disease. Frontotemporal dementia receives its name from the regions of the brain that are most commonly affected in the condition. Brain degeneration tends to affect the frontal lobes of the brain – which support speaking, planning and controlling behaviour – and the temporal lobes which are responsible for comprehending speech, storing factual information about the world, and memory.
(1) Behavioural-variant Frontotemporal dementia (bvFTD) is characterised by personality changes and behavioural disturbances. Some of the most common symptoms include a of loss inhibition (saying or doing things which are socially inappropriate), reduced empathy (problems understanding and responding to the needs of others), problems with planning and organising activities, increased distractibility, changes in food preference (a propensity to eat large quantities of sweet food) and a tendency to develop compulsive rituals (e.g. watching the same movie repeatedly).
(2) Progressive non-fluent aphasia (PNFA) is characterised by problems with speech production. Individuals may struggle to find the correct words when engaging in conversation. Often individuals will struggle to pronounce words correctly (especially if they have more than two syllables), and their speech will lack appropriate grammar. Problems understanding speech can also be present, especially if the sentence contains complex grammar.
(3) Semantic dementia is characterised by a selective deficit of semantic memory, which is our memory store for factual information about the world around us – e.g., the knowledge that apples are fruit is a semantic memory. Individuals affected by this condition have difficulty understanding the meaning of written and spoken language, pictures and objects. In some cases of semantic dementia a mild form of the behavioural changes seen in behavioural-variant Frontotemporal dementia may develop as the condition progresses.