Paraphrasing means rewriting a statement or a paragraph in your own words, without changing the meaning. It is usually done when the paraphrasing author wants to elaborate more on the subject, or he fears that the original version is too difficult to understand.
It is not a summary as summary is a shorter version of a given text. Paraphrasing includes both key points and sub points and can even be longer than the original source.
You should always cite a paraphrase, otherwise it's plagiarism as you are using somebody else's words.
The answer is 8% and 12% Dementia happen because many of the brain cells became dead and unable to fulfill its usual function. The dead cells create lesser compositon inside the brain which lead to lower-than average brain weight.
