pd is typically a 20 year illness but can range from 10 - 40 years. there are 2 basic subcategories: tremor dominant and postural instability/gait disturbance (pigd). the tremor dominant is much less likely to have memory problems and has a better prognosis. in my experience - disability from work which i define as needing 12 hours to do an 8 hour work-day - is seen on an average of 12 years after diagnosis. advanced may affect thinking. most of the time the cognitive changes have to do with speed of thinking - just like the motor changes have to do with the speed of moving. think of it as a road that can only handle a certain amount of traffic. if it is crowded with thoughts a person will have some trouble with word finding - or juggling all of the information. this sometimes concerns family members and patients because they appear to not be remembering things. in reality they did not move the information down the road to a memory circuit (did not learn if you will). so remember to take things more slowly. .
how does parkinson's disease affect longevity and mental clarity?