Didn't think about the gradual aspect. I don't know too much about apart from my grandfather but it seemed like 0 to 100 pretty quickly. Do people have different rates of the neurone activity reducing? From what I saw it was pretty swift. Is there a scale on how quick or slow it is?
It can range anywhere from months to years depending on the type and how old someone is. Over weeks or months is known as rapidly progressive dementia. It's often categorized into 7 stages;
1. Appears normal. Changes are happening in the brain with no symptoms yet.
2. Very mild. Not much worse. Forgetfulness is brushed off as getting old.
3. Mild. Increased forgetfulness and confusion. Family may start to notice something wrong.
4. Moderate. Short term memory is worsening. Complex tasks and personal affairs become difficult. Denial and social withdrawal is common. Doctors can make a clear diagnosis here.
5. Moderately Severe. Begins forgetting major life events and begins needing help with getting dressed and cooking.
6. Severe. Forgets the names of family members. Difficulty speaking. Delusions, depression and agitation common.
7. Very severe. The end, they forget how to talk, eat, walk and eventually die. Infections of the brain are the common way to die. Since they can't eat, malnutrition is how some folks die too.
