I came across this article which says that -
“The risk estimates for Parkinson’s disease in autistic people range from 15 to 20 percent, compared with about 1 percent in the general population.”
Given that about 2% of the population is autistic, and most autistic adults remain unidentified, I wonder how many people with Parkinson’s are autistic?
Hi @Lemon, 
I know it has been a while since you posted this thread, but I just wanted to chime in with some information that I thought would be helpful to this topic.
Unfortunately we don’t know how many people in the UK have autism and Parkinson’s. But in some cases symptoms of autism crossover with symptoms of Parkinson’s such as bradykinesia (slowness of movement).
There have been some research studies looking into the link between autism and Parkinson’s and the results have shown that there may well be an increased frequency of Parkinsonism in older people with Autism. However the studies that have looked into this have been small so there needs to be further large scale research to replicate the results before definitive conclusions can be made.
I hope you find this helpful.
Best wishes,
Reah
one possible cause for a increased risk of parkinson’s in autistic people is that autism is often associated with having too many neurons due to diminished pruning around ages 1 through 3. this means that the neurons of the brainstem, midbrain, and basal forebrain have to serve a lot more customers than usual. for example, in a typical human each dopaminergic neuron in the substantia nigra (SN) innervates roughly 2 million neurons in the striatum, thalamus, cortex, etc. these cells obviously do rough duty and are very stressed and liable to pop off if they are also diseased. for an autistic person, the SN neurons might each have 10 to 15 % more customers (for clarity, i’m making a wild guess about the percentage!) and this might mean that the SN neurons die more readily because they are really stressed. so parkinson’s might progress faster and do more damage in autistic people.
