Parkinsonism as a Sequela of SARS-CoV-2 Infection: Pure Hypoxic Injury or Additional COVID-19-Related Response?

Post-COVID parkinsonism: A scoping review

BACKGROUND

The clinical features and outcomes of post-COVID parkinsonism have not been organized systematically, and the possible correlations between COVID-19 and parkinsonism have not been elucidated. This scoping review addresses these two unmet needs.

METHODS

We searched two databases (Pubmed, Embase) for all published cases of post-COVID parkinsonism. Data were extracted from eligible studies using standardized forms and predefined inclusion and exclusion criteria. The patients' clinical features, their diagnosis and outcomes were assessed objectively.

RESULTS

Twenty-six cases of post-COVID parkinsonism were reported in 17 publications. Their presenting features were grouped into three clinical syndromes: typical parkinsonian motor syndrome (12 patients), parkinsonism with postural instability and gait disorder (three), or encephalopathy with parkinsonism (10). Patients had the following diagnoses: clinically established Parkinson's disease (PD, three cases), clinically probable PD (eight), clinically probable multiple system atrophy (one), acquired parkinsonism (six), unclassified parkinsonism (eight). Isolated parkinsonian motor syndromes typically followed uncomplicated COVID-19 illness or pneumonia; instead, encephalopathy with parkinsonism was observed following a wide spectrum of COVID-19-related presentations, including severe forms. PD cases mainly occurred following uncomplicated COVID-19, whereas acquired or unclassified parkinsonism were reported following different COVID-19 presentations.

CONCLUSIONS

Patients with uncomplicated COVID-19 are more likely to present PD and no signs of encephalopathy. There is no demonstration of a causative role of COVID-19, which can be coincidental in several cases. Patients with encephalopathy and parkinsonism constitute a distinct subset, suggesting a potentially different pathogenic role of SARS-CoV-2 infection. These findings provide a basis for further studies in the post-pandemic phase.

De Novo Movement Disorders Associated with COVID-19- A Systematic Review of Individual Patients

Background

COVID-19 infection is associated with neurological manifestations, including various types of movement disorders (MD). A thorough review of individual patients with COVID-19-induced MD would help in better understanding the clinical profile and outcome of these patients and in prognostication.

Objective

We conducted an individual patient-systematic review to study the clinical and imaging profile and outcomes of patients with COVID-19-associated MD.

Methods

A systematic literature search of PubMed, EMBASE, and Cochrane databases was conducted by two independent reviewers. Individual patient data COVID from case reports and case series on COVID-19-associated MD, published between December 2019 and December 2022, were extracted and analyzed.

Results

Data of 133 patients with COVID-19-associated MD from 82 studies were analyzed. Mean age was 55 ± 18 years and 77% were males. A mixed movement disorder was most commonly seen (41%); myoclonus-ataxia was the most frequent (44.4%). Myoclonus significantly correlated with age (odds ratio (OR) 1.02 P = 0.03, CI 1-1.04). Tremor had the longest latency to develop after SARS-CoV-2 infection [median (IQR) 21 (10-40) days, P = 0.009, CI 1.01-1.05]. At short-term follow-up, myoclonus improved (OR 14.35, P value = 0.01, CI 1.71-120.65), whereas parkinsonism (OR 0.09, P value = 0.002, CI 0.19-0.41) and tremor (OR 0.16, P value = 0.016, CI 0.04-0.71) persisted.

Conclusion

Myoclonus-ataxia was the most common movement disorder after COVID-19 infection. Myoclonus was seen in older individuals and usually improved. Tremor and parkinsonism developed after a long latency and did not improve in the short-term.

COVID-19 and neurological disorders: what might connect Parkinson's disease to SARS-CoV-2 infection

SARS-CoV-2 infection leading to Coronavirus disease 19 (COVID-19) rapidly became a worldwide health emergency due to its elevated infecting capacity, morbidity, and mortality. Parkinson’s disease (PD) is the second most common neurodegenerative disorder and, nowadays the relationship between SARS-CoV-2 outbreak and PD reached a great interest. Apparently independent one from the other, both diseases share some pathogenetic and clinical features. The relationship between SARS-CoV-2 infection and PD is complex and it depends on the direction of the association that is which of the two diseases comes first. Some evidence suggests that SARS-CoV-2 infection might be a possible risk factor for PD wherein the exposure to SARS-CoV-2 increase the risk for PD. This perspective comes out from the increasing cases of parkinsonism following COVID-19 and also from the anatomical structures affected in both COVID-19 and early PD such as olfactory bulb and gastrointestinal tract resulting in the same symptoms such as hyposmia and constipation. Furthermore, there are many reported cases of patients who developed hypokinetic extrapyramidal syndrome following SARS-CoV-2 infection although these would resemble a post-encephalitic conditions and there are to date relevant data to support the hypothesis that SARS-CoV-2 infection is a risk factor for the development of PD. Future large, longitudinal and population-based studies are needed to better assess whether the risk of developing PD after COVID-19 exists given the short time span from the starting of pandemic. Indeed, this brief time-window does not allow the precise estimation of the incidence and prevalence of PD after pandemic when compared with pre-pandemic era. If the association between SARS-CoV-2 infection and PD pathogenesis is actually putative, on the other hand, vulnerable PD patients may have a greater risk to develop COVID-19 being also more prone to develop a more aggressive disease course. Furthermore, PD patients with PD showed a worsening of motor and non-motor symptoms during COVID-19 outbreak due to both infection and social restriction. As well, the worries related to the risk of being infected should not be neglected. Here we summarize the current knowledge emerging about the epidemiological, pathogenetic and clinical relationship between SARS-CoV-2 infection and PD.

Parkinson's Disease, SARS-CoV-2, and Frailty: Is There a Vicious Cycle Related to Hypovitaminosis D?

The literature has long established the association between aging and frailty, with emerging evidence pointing to a relationship between frailty and SARS-CoV-2 contagion. The possible neurological consequences of SARS-CoV-2 infection, associated with physical and cognitive frailty, could lead to a worsening of Parkinson's disease (PD) in infected patients or-more rarely-to an increase in the Parkinsonian symptomatology. A possible link between those clinical pictures could be identified in vitamin D deficiency, while the whole process would appear to be associated with alterations in the microbiota-intestine-brain axis that fall within the α-Synuclein Origin site and Connectome (SOC) model, and allow for the identification of a body-first PD and a brain-first PD. The model of care for this condition must consider intrinsic and extrinsic variables so that care by a multidisciplinary team can be successfully predicted. A multidimensional screening protocol specifically designed to identify people at risk or in the early stages of the disease should begin with the investigation of indices of frailty and microbiota-intestine-brain axis alterations, with a new focus on cases of hypovitaminosis D.

COVID19-associated new-onset movement disorders: a follow-up study

BACKGROUND

Neurological symptoms are common manifestation in acute COVID-19. This includes hyper- and hypokinetic movement disorders. Data on their outcome, however, is limited.

METHODS

Cases with new-onset COVID-19-associated movement disorders were identified by searching the literature. Authors were contacted for outcome data which were reviewed and analyzed.

RESULTS

Movement disorders began 12.6 days on average after the initial onset of COVID-19. 92% of patients required hospital admission (mean duration 23 days). In a fraction of patients (6 of 27; 22%; 4 males/2 females, mean age 66.8 years) the movement disorder (ataxia, myoclonus, tremor, parkinsonism) was still present after a follow-up period of 7.5 ± 3 weeks. Severe COVID-19 in general and development of encephalopathy were risk factors, albeit not strong predictors, for the persistence.

CONCLUSIONS

The prognosis of new-onset COVID-19-associated movement disorder appears to be generally good. The majority recovered without residual symptoms within several weeks or months. Permanent cases may be due to unmasking of a previous subclinical movement disorder or due to vascular/demyelinating damage. Given the relatively low response rate of one third only and the heterogeneity of mechanisms firm conclusions on the (long-term) outome cannot, however, be drawn.

Gastrointestinal, Respiratory, and Olfactory Neurotropism of Sars-Cov2 as a Possible Trigger of Parkinson's Disease: Is a Multi-Hit Multi-Step Process on the Cards

Since the first emergence of COVID-19 on the global stage, there has been a wealth of evidence to suggest that SARS-Cov2 is not merely a pulmonary pathogen. This virus is unique in its ability to disrupt cellular pathways related to protein homeostasis, mitochondrial function, stress response, and aging. Such effects raise concerns about the long-term fate of survivors of COVID-19 infection, particularly regarding neurodegenerative diseases. The concept of interaction between environmental factors and alpha-synuclein formation in the olfactory bulb and vagal autonomic terminals with subsequent caudo-cranial migration has received much attention in the context of PD pathogenesis. Anosmia and gastrointestinal symptoms are two well-known symptoms of COVID-19, with evidence of an olfactory bulb and vagal infiltration by SARS-CoV2. This raises the possibility of the spread of the viral particles to the brain along multiple cranial nerve routes. Neurotropism, coupled with the ability of the SARS-Cov2 virion to induce abnormal protein folding and stress responses in the central nervous system, in presence of an inflammatory milieu, reinforced by hypoxia, coagulopathy, and endothelial dysfunction, reverberates the intriguing possibility of activation of a neurodegenerative cascade leading to the development of pathological alpha-synuclein aggregates and thus, triggering the development of PD in survivors of COVID19. This review attempts to summarize and critically appraise existing evidence from basic science research and clinical reports of links between COVID-19 and PD and explores the prospect of a multi-hit pathophysiological process, induced by SARS-Cov2 infection, ultimately converging on perturbed cellular protein homeostasis, which although is intriguing, presently lacks robust evidence for confirmation.

Viruses, parkinsonism and Parkinson's disease: the past, present and future

Parkinsonism secondary to viral infections is not an uncommon occurrence and has been brought under the spotlight with the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A variety of viruses have been described with a potential of inducing or contributing to the occurrence of parkinsonism and Parkinson's disease (PD), although the relationship between the two remains a matter of debate originating with the description of encephalitis lethargica in the aftermath of the Spanish flu in 1918. While some viral infections have been linked to an increased risk for the development of PD, others seem to have a causal link with the occurrence of parkinsonism. Here, we review the currently available evidence on viral-induced parkinsonism with a focus on potential pathophysiological mechanisms and clinical features. We also review the evidence on viral infections as a risk factor for developing PD and the link between SARS-CoV-2 and parkinsonism, which might have important implications for future research and treatments.

New-onset Parkinsonism as a Covid-19 infection sequela: A systematic review and meta-analysis

Background

There remains a scarcity of literature regarding COVID-19 and its neurological sequelae. This study highlights Parkinsonism as a post-COVID-19 sequela and helps us understand a possible link between the two.

Methods

A literature search covering relevant databases was conducted for studies reporting the development of Parkinsonism in patients recovering from COVID-19 infection. A quality assessment tool developed by The Joanna Briggs Institute Critical Appraisal tools for the assessment of case reports was utilized. Fisher's exact test was used to explore the factors associated with COVID-19 and Parkinsonism as its complication.

Results

Ten studies were included in our study. The median age of patients was 60.0, with an interquartile range of 42.5–72.0. There were 8 males (61.5%) patients, and 53.8% of cases were reported to have at least one comorbidity. Cogwheel rigidity was the most common symptom of Parkinsonism in 11 patients. While the most standard treatment modality used was Levodopa in 76.9% of cases. Using the Fisher's Exact test, it was identified that 10 patients (76.9%) with bradykinesia made a full recovery.

Conclusion

Despite presumed “recovery” from COVID-19, patients still face a wide range of neurological complications. One of these complications presenting as Parkinsonism requires health care professionals to be on the lookout for the long-term effects of COVID-19. Hence, our study provides information on the possible likely hood of a link between COVID-19 and the development of Parkinsonism as post-COVID neurological sequelae.

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There have been well-documented reports about the occurrence of parkinsonism after viral infections.

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10 studies including 13 patients reported the development of parkinsonism in individuals who recovered from COVID-19 infection.

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The commonest symptom of parkinsonism reported in these individuals was cogwheel rigidity 84.6%.

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53.8% of individuals fully recovered and had their symptoms resolved after treatment.

COVID-19 and Parkinsonism: A Critical Appraisal

A few cases of parkinsonism linked to COVID-19 infection have been reported so far, raising the possibility of a post-viral parkinsonian syndrome. The objective of this review is to summarize the clinical, biological, and neuroimaging features of published cases describing COVID-19-related parkinsonism and to discuss the possible pathophysiological mechanisms. A comprehensive literature search was performed using NCBI’s PubMed database and standardized search terms. Thirteen cases of COVID-19-related parkinsonism were included (7 males; mean age: 51 years ± 14.51, range 31–73). Patients were classified based on the possible mechanisms of post-COVID-19 parkinsonism: extensive inflammation or hypoxic brain injury within the context of encephalopathy (n = 5); unmasking of underlying still non-symptomatic Parkinson’s Disease (PD) (n = 5), and structural and functional basal ganglia damage (n = 3). The various clinical scenarios show different outcomes and responses to dopaminergic treatment. Different mechanisms may play a role, including vascular damage, neuroinflammation, SARS-CoV-2 neuroinvasive potential, and the impact of SARS-CoV-2 on α-synuclein. Our results confirm that the appearance of parkinsonism during or immediately after COVID-19 infection represents a very rare event. Future long-term observational studies are needed to evaluate the possible role of SARS-CoV-2 infection as a trigger for the development of PD in the long term.

Coronavirus Disease 2019 and related Parkinsonism: the clinical evidence thus far

Background

The Coronavirus disease 2019 (Covid‐19) pandemic has fueled both research and speculation, as to whether it could be a “perfect storm” for a post‐Covid emergence of parkinsonism in some susceptible individuals, analogous to the post‐encephalitic parkinsonism reported after the 1918 influenza epidemic. This theory is further augmented by reports of a pathogenic effect of the Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2) on the central nervous system with specific impact on the dopaminergic pathway, as well as the possibility of the virus to selectively bind to Angiotensin‐Converting Enzyme‐2 (ACE‐2); these molecules are expressed abundantly in the midbrain dopamine neurons and, are likely involved in several cellular mechanisms cited in Parkinson's Disease (PD) pathophysiology.

Objectives—Methods

Therefore, we performed a review of the literature up to February 2022 to explore the current landscape considering published cases of new‐onset parkinsonism after a SARS‐CoV‐2 infection in otherwise healthy individuals. We summarized their clinical features, diagnostic and treatment approaches, discussing potential underlying mechanisms in light of PD pathogenesis theories.

Results

Twenty cases that developed parkinsonian features simultaneously or shortly after a reported SARS‐CoV‐2 infection were reviewed. In 11 of them, parkinsonism appeared in the context of encephalopathy, while four patients developed post‐infectious parkinsonism without encephalopathy, and four bore similarities to idiopathic PD. Nine patients exhibited a good response to dopaminergic therapy, while four responded to immunomodulatory treatment.

Conclusions

Available data does not yet justify a clear association between the Covid‐19 pandemic and a parkinsonism wave. However, vigilance is necessary, as long‐term effects might have not been revealed.

Covid-19, nervous system pathology, and Parkinson's disease: Bench to bedside

Coronavirus disease 2019 (Covid-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is primarily regarded as a respiratory disease; however, multisystemic involvement accompanied by a variety of clinical manifestations, including neurological symptoms, are commonly observed. There is, however, little evidence supporting SARS-CoV-2 infection of central nervous system cells, and neurological symptoms for the most part appear to be due to damage mediated by hypoxic/ischemic and/or inflammatory insults. In this chapter, we report evidence on candidate neuropathological mechanisms underlying neurological manifestations in Covid-19, suggesting that while there is mostly evidence against SARS-CoV-2 entry into brain parenchymal cells as a mechanism that may trigger Parkinson's disease and parkinsonism, that there are multiple means by which the virus may cause neurological symptoms.

COVID-19: The cynosure of rise of Parkinson's disease

Parkinson's disease (PD) is one of the most common age-related disorders globally. The pathophysiological mechanisms and precipitating factors underlying PD manifestations, including genetic and environmental parameters, inflammation/stress and ageing, remain elusive. Speculations about whether the Coronavirus Disease 2019 (Covid-19) pandemic could be a pivotal factor in affecting the prevalence and severity of PD or triggering a wave of new-onset parkinsonism in both the near and distant future have recently become very popular, with researchers wondering if there is a changing trend in current parkinsonism cases. Could the current understanding of the Covid-19 pathophysiology provide clues for an impending rise of parkinsonism cases in the future? Are there any lessons to learn from previous pandemics? Our aim was to look into these questions and available current literature in order to investigate if Covid-19 could constitute a cardinal event affecting the parkinsonism landscape.

Covid-19 and Parkinson's disease: Acute clinical implications, long-COVID and post-COVID-19 parkinsonism

The Coronavirus Disease 2019 (Covid-19), caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), has led to unprecedented challenges for the delivery of healthcare and has had a clear impact on people with chronic neurological conditions such as Parkinson's disease (PD). Acute worsening of motor and non-motor symptoms and long-term sequalae have been described during and after SARS-CoV-2 infections in people with Parkinson's (PwP), which are likely to be multifactorial in their origin. On the one hand, it is likely that worsening of symptoms has been related to the viral infection itself, whereas social restrictions imposed over the course of the Covid-19 pandemic might also have had such an effect. Twenty cases of post-Covid-19 para-infectious or post-infectious parkinsonism have been described so far where a variety of pathophysiological mechanisms seem to be involved; however, a Covid-19-induced wave of post-viral parkinsonism seems rather unlikely at the moment. Here, we describe the interaction between SARS-CoV-2 and PD in the short- and long-term and summarize the clinical features of post-Covid-19 cases of parkinsonism observed so far.

An atypical case of corticobasal syndrome with psychotic depression and delusional jealousy

Corticobasal syndrome (CBS) is one of the Parkinson-plus disorders. While initially defined as a movement disorder rather than cognition, it is now known that CBS is related to various psychiatric symptoms. We describe a patient clinically diagnosed with CBS whose initial presentation was psychiatric and rather atypical. His clinical picture included psychotic depression and delusional jealousy. Misdiagnosing these syndromes may delay the initiation of the treatment and worsen the patients' condition, as well as increase the burden of the caretakers. Finally, COVID-19-related changes in the organization of health services complicated the diagnosis and follow-up processes of this patient.