What is the difference between presenile dementia and regular dementia?

Terminology: A difference in terminology... Presenile dementia referred to a dementia with onset prior to 60-> 65 yrs of age, whereas in dementia the onset was later than 65 years. The etiology of the dementia could be the same, that being a dementia of the Alzheimer's type, pick's disease, lewy body dementia, vascular dementia or mixed type. Some can be diagnosed by symptoms and imaging, tissue is gold standard.

Age of onset: Early onset dementia usually hereditary may b referred 2 as presenile.