Table 1.
Highlights of the link between COVID-19 and Parkinson’s disease
| Subject | Topic | Highlight |
|---|---|---|
| Impact of COVID-19 on PD | Effect on motor and non-motor symptoms |
1. Worsening of motor symptoms, such as rigidity and tremor 2. Experiencing motor fluctuations 3. Triggering new motor symptoms 4. Worsening non-motor symptoms, such as mood, sleep, cognition, dysautonomia and hallucination 5. COVID-19 has harmful effects on motor and non-motor symptoms in PD patients both directly and indirectly |
| Effect on disease progression | 1. Only one retrospective longitudinal study revealed increased motor symptom progression of PD during the COVID-19 pandemic | |
| Effect on PD-related mortality |
1. Increased PD-related mortality rates during the COVID-19 pandemic 2. PD with older age, advanced course, reduction in medication and comorbidities are more likely to have increased risk of mortality 3. Negative findings indicated that the mortality of COVID-19 in PD patients does not differ from the general population |
|
| Trigger for PD |
1. Cases have been reported with development of parkinsonism after COVID-19 infection 2. Infection of dopaminergic neurons with the H1N1 influenza virus results in aggregation of α-synuclein 3. Viral infections trigger α-synucleinopathies in animal models 4. COVID-19 infection could trigger neurodegeneration with mechanisms not clearly determined |
|
| Impact of PD on COVID-19 | Vulnerability to COVID-19 infection |
1. Possibly higher risks of COVID-19 infection and hospitalization 2. Contrary results were also reported that PD do not differ from general population in the COVID-19 risk |
| Prognosis of COVID-19 infection |
1. Enhanced risk of disease severity and mortality in PD patients than in non-PD patients 2. Inconsistent results were also reported that the prognosis of COVID‐19 patients seems comparable in patients with PD and those without it |
|
| Management of PD during COVID-19 pandemic | Modification of care strategies in PD |
1. Pandemic profoundly changes the way of PD management 2. Telemedicine services with digital-visits, e-rehabilitation, and remote programming are accessible and efficient for PD during the pandemic |
| Potential impact of drug therapies for PD on COVID-19 |
1. Amantadine can be potentially used for the prevention of COVID-19 2. Levodopa has potential impacts on SARS-CoV-2 3. Dopamine agonists may worsen the outcomes of patients with COVID-19 infection 4. Entacapone may be a potential drug against SARS-CoV-2 5. Clozapine treatment is linked with an increased risk of COVID-19 infection 6. Vitamin D supplementation is identified as a protective factor for COVID-19 infection |
|
| Effect of COVID-19 vaccines on PD |
1. COVID-19 vaccines were known or expected not to interact with PD 2. Types or incidence of side effects of vaccines in PD seem no different from the general population 3. Case reports of developing severe dyskinesia or worsening of parkinsonian symptoms after receiving vaccines 4. A case report of improvement of motor and non-motor symptoms after receiving vaccines 5. Amantadine was hypothesized of potential interference with COVID-19 vaccines |
|
| Mechanisms of the link between COVID-19 and PD |
1. SARS-CoV-2 virus enters the CNS through olfactory bulb, by axonal transport from peripheral nerves, or by the hematogenous pathway via BBB 2. Systemic inflammation and sepsis which promote hypercoagulable response to form clots in brain vessels, and cytokine storm leading to hyper-inflammation and neuroinflammation 3. SARS-CoV-2 could bind to ACE2 receptors on dopaminergic neurons, which might cause neuroinflammation, excessive oxidative stress, abnormal immune response and pathological α-synuclein accumulation, leading to dopaminergic neuronal death |
ACE2 Angiotensin-converting enzyme 2; BBB Blood brain barrier; CNS Central nervous system; COVID-19 Coronavirus disease 2019; PD Parkinson’s disease; SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2