"A prominent theory for explaining Parkinson's disease, put forth by Heiko Braak, a German doctor who studies Parkinson's, aligns well with all these long COVID findings. It states that Parkinson's is caused by a pathogen affecting either the nasal cavity or digestive system, thereby first initiating protein misfolding in the peripheral nervous system before spreading into the brain later on (sometimes decades later). This is why the onset of Parkinson's often entails autonomic dysfunction — which means involuntary processes like heart rate, blood pressure, respiration, etc. are compromised. As autonomic dysfunction is a common symptom of long COVID, it is thus possible that the post-acute infection syndrome mechanism responsible for long COVID progresses to the central nervous system over time and could eventually present as Parkinson's disease or a similar disorder.
In other words, while long COVID is not caused by the lingering viral remnants of COVID-19 per se, the initial infection could be precipitating amyloid buildup and Lewy body formation. If this is so, long COVID would mimic a chronic or slowly-evolving infection caused by the virus, similar to other post-acute infection syndrome cases, with the symptoms fluctuating and emerging unpredictably as the amyloids slowly spread throughout the nervous system."