Yes, the nitro-striatial pathway, a dopaminergic system.
Use of levo - dopa, a blood brain barrier permeant dopamine precursor, can help alleviate symptoms.
Cerebellar control remains and, oddly, patients can retain the ability for fine motor skill activities, such as surgery, despite otherwise having shuffling gait and shaky hands under normal behavior.
Psychosis or dementia is not a hallmark of Parkinson’s, although, recently, effects on mental states in some cases are beginning to be documented.
“...in some cases are beginning to be documented.”
On a personal note both my grandfathers had parkinsons and both developed the same syptoms of Bidem with balance problems, forgetfullness and slurred speech.
But a little more informtion on this comes from John Hopkins:
“Parkinson disease causes physical symptoms at first. Problems with cognitive function, including forgetfulness and trouble with concentration, may start later. As the disease gets worse over time, about 4 in 5 people develop dementia.”
I guess it depends on what you read. I found this.
wy69