What disease is it that leads to fronto-temporal dementia?

Alzheimer's does: The term pick's disease was used is a sub-type where damage to these areas was the primary issue. It is too complex for a brief answer but the mayo clinic has a good article: http://www.Mayoclinic.Org/diseases-conditions/frontotemporal-dementia/basics/causes/con-20023876 hope this helps.

See below: It affects the frontal lobes (front) and temporal lobes (sides) of the brain. Onset is usually earlier than alzheimer's. Initial sx may involve changes in personality, judgement and social functioning. Pick's disease is one of the forms of the frontotemporal dementia. Here's a link to fuller description of the disease http://www.Alz.Org/alzheimers_disease_frontotemporal_dementia.Asp.