PD's distorted neuro-signaling makes it a multi-system disorder. if PD caused you to die from heart failure or stroke, or from a fall or from pneumonia due to swallowing errors when unable to cough it clear (due to lack of related ANS muscle control), all of these due to faulty signals caused by PD, then PD is the root cause.

had to write about this as a stand-alone bottomline concept...

let not semantics confuse what is very simple math/logic:  

PD's distorted neuro-signaling makes it a multi-system disorder.  if PD caused you to die from heart failure or stroke, or from a fall or from pneumonia resulting from swallowing errors you were unable to cough clear (due to lack of related ANS muscle control), and all of these are due to faulty signals caused by PD, then PD is the root cause.  figure it out.

https://parkinsonsdisease.net/answers/life-expectancy

What is the Life Expectancy of People with Parkinson's?   

...

People with PD are at higher risk of falling, and serious falls that require surgery carry the risk of infection, adverse events with medication and anesthesia, heart failure, and blood clots from immobility.

Aspiration pneumonia

Pneumonia is a common cause of death, and those with PD are at risk for aspiration pneumonia. People with PD often have problems with swallowing, so the risk of aspirating food or drink, or having food or drink going "down the wrong [wind] pipe" is higher.

In Parkinson's, the person may not be able to cough up the food or drink they aspirated, and it can remain in the lungs, eventually causing an infection.

Even with general pneumonia, when coughing is weakened, as in PD, the mucus and other material that needs to be coughed up isn't able to be expelled, and this makes effective treatment of pneumonia more difficult in those with PD.

...

PD is not the direct cause of death for these patients, but rather complications stemming from PD may be the true cause.  [let not semantics confuse what is very simple math/logic:  

PD's distorted neuro-signaling makes it a multi-system disorder.  if PD caused you to die from heart failure or stroke, or from a fall or from pneumonia due to swallowing errors when unable to cough it clear (due to lack of related ANS muscle control), all of these due to faulty signals caused by PD, then PD is the root cause.  figure it out; it's hidden in plain sight.]