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

Myoclonus: an update

PURPOSE OF REVIEW

Myoclonus, a common hyperkinetic movement disorder, can be disabling for patients. It is important to identify and classify myoclonus correctly to ensure appropriate workup and treatment. While the clinical history, examination, and process of classifying myoclonus remain largely unchanged, new causes and triggers for myoclonus are being elucidated, and new genetic causes have been found. Treatment can be challenging, though preliminary data about new options has been promising.

RECENT FINDINGS

In this article, we will briefly outline the process of classifying and treating myoclonus. We will then discuss three specific scenarios where myoclonus has been identified: myoclonus associated with SARS-CoV-2 infections, spinal myoclonus following surgery or anesthesia of the spine, and auricular myoclonus. We will also discuss new genetic findings associated with myoclonus-dystonia, and promising results regarding the use of perampanel in treating myoclonus.

SUMMARY

The process of describing unique scenarios associated with myoclonus has helped us build our understanding of the causes, genetic background, expected prognosis, and effective treatment of specific types of myoclonus. We hope that further studies on this topic will help tailor treatment.

Definition, diagnosis and classification of infection-related movement disorders: Consensus proposal

BACKGROUND

Infection-related movement disorders (IRMD) present a complex diagnostic challenge due to the broad phenotypic spectrum, the variety of possible infectious aetiologies, and the complicated underlying mechanisms. Yet, a comprehensive framework for classifying IRMD is lacking.

METHODS

An international consensus panel under the directives of the Movement Disorders Society Infection-Related Movement Disorders Study Group developed a comprehensive definition and a consensus classification system. Case scenarios were used for validation.

RESULTS

A definition for IRMD and a two-axis-based classification system consisting of six descriptors are proposed, intended as tools for researchers and clinicians. Collected information on clinical characteristics, investigational findings, the infectious organism and presumed pathogenesis facilitate the evaluation of diagnostic certainty.

CONCLUSION

The proposed framework will serve for optimised diagnostic algorithms, systematic aggregation of informative datasets across studies, and ultimately improved care and outcome of patients with IRMDs.

Neurological Manifestations of Acute SARS-CoV-2 Infection in Pediatric Patients: A 3-Year Study on Differences between Pandemic Waves

This study analyzed the neurological manifestation profiles of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection across pandemic waves in pediatric patients. The study collected data on patients aged between 0 and 18 years, diagnosed with acute SARS-CoV-2 infection, admitted to a pediatric tertiary hospital between 1 March 2020 and 28 February 2023. This study included 1677 patients. Neurological manifestations were noted in 10% (n = 168) of patients with a median age of 3.2 years (interquartile range: 1-11.92). Neurological manifestations were significantly associated with the pandemic waves (p = 0.006) and age groups (p < 0.001). Seizures were noted in 4.2% of cases and reached an increasing frequency over time (p = 0.001), but were not associated with age groups. Febrile seizures accounted for the majority of seizures. Headache was reported in 2.6% of cases and had similar frequencies across the pandemic waves and age groups. Muscular involvement was noted in 2% of cases, reached a decreasing frequency over time (p < 0.001), and showed different frequencies among the age groups. Neurological manifestations of acute SARS-CoV-2 infection exhibit distinct patterns, depending on the pandemic wave and patient age group. The Wuhan and Omicron waves involved the nervous system more often than the other waves.

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.

Long-term neuropsychiatric sequelae of Delta versus Omicron SARS-CoV-2 infection

OBJECTIVES

Studies have reported increased rates of long-term neuropsychiatric sequelae after SARS-CoV-2 infection using electronic health-record (EHR) data; however, the majority were conducted before Omicron and booster rollout. We estimated the long-term risks and excess burdens of pre-specified new-incident neuropsychiatric diagnoses after Delta versus Omicron BA.1/2 infection in a highly-vaccinated and boosted cohort of adult Singaporeans.

METHODS

The national SARS-CoV-2 testing registry was used to construct cohorts of Singaporean adults infected during periods of Delta and Omicron BA.1/2 predominance and a contemporaneous test-negative control group. New-incident neuropsychiatric diagnoses recorded in the national health care claims database were identified up to 300 days postinfection. Risks and excess burden were estimated using a doubly robust competing-risks survival analysis.

RESULTS

104 179 and 375 903 infected cases were assigned to Delta and Omicron cohorts and compared against test-negative controls (Delta: N = 666 575 and Omicron: N = 619 379). Elevated risk of cognition or memory disorders was consistently reported across Omicron (Adjusted hazards ratio [aHR], 1.24; 95% CI, 1.12-1.38) and Delta cohorts (aHR, 1.63; 95% CI, 1.39-1.92). Delta-variant infection was associated with an increased risk of anosmia or dysgeusia (aHR, 4.53; 95% CI, 2.78-7.41) and psychosis (aHR, 1.65; 95% CI, 1.22-2.22). By contrast, Omicron-variant infection was associated with a risk of abnormal involuntary movements (aHR, 1.93; 95% CI, 1.32-2.83). Risks of neuropsychiatric sequelae predominantly accrued in hospitalized individuals.

DISCUSSIONS

A modestly increased risk of cognition and memory disorders at 300 days after SARS-CoV-2 infection was observed among adult Singaporeans infected during the Delta/Omicron BA.1/2 transmission. There was no overall increased risk of neuropsychiatric sequelae observed across other domains. Variant-specific differences were also observed in individual neuropsychiatric sequelae, including an elevated risk of anosmia or dysgeusia after Delta-variant infection.

Meta-analysis of the serum/plasma proteome identifies significant associations between COVID-19 with Alzheimer's/Parkinson's diseases

In recent years, we have seen the widespread devastations and serious health complications manifested by COVID-19 globally. Although we have effectively controlled the pandemic, uncertainties persist regarding its potential long-term effects, including prolonged neurological issues. To gain comprehensive insights, we conducted a meta-analysis of mass spectrometry-based proteomics data retrieved from different studies with a total of 538 COVID-19 patients and 523 healthy controls. The meta-analysis revealed that top-enriched pathways were associated with neurological disorders, including Alzheimer's (AD) and Parkinson's disease (PD). Further analysis confirmed a direct correlation in the expression patterns of 24 proteins involved in Alzheimer's and 23 proteins in Parkinson's disease with COVID-19. Protein-protein interaction network and cluster analysis identified SNCA as a hub protein, a known biomarker for Parkinson's disease, in both AD and PD. To the best of our knowledge, this is the first meta-analysis study providing proteomic profiling evidence linking COVID-19 to neurological complications.

Virus-induced brain pathology and the neuroinflammation-inflammation continuum: the neurochemists view

Fascinatingly, an abundance of recent studies has subscribed to the importance of cytotoxic immune mechanisms that appear to increase the risk/trigger for many progressive neurodegenerative disorders, including Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis, and multiple sclerosis. Events associated with the neuroinflammatory cascades, such as ageing, immunologic dysfunction, and eventually disruption of the blood-brain barrier and the "cytokine storm", appear to be orchestrated mainly through the activation of microglial cells and communication with the neurons. The inflammatory processes prompt cellular protein dyshomeostasis. Parkinson's and Alzheimer's disease share a common feature marked by characteristic pathological hallmarks of abnormal neuronal protein accumulation. These Lewy bodies contain misfolded α-synuclein aggregates in PD or in the case of AD, they are Aβ deposits and tau-containing neurofibrillary tangles. Subsequently, these abnormal protein aggregates further elicit neurotoxic processes and events which contribute to the onset of neurodegeneration and to its progression including aggravation of neuroinflammation. However, there is a caveat for exclusively linking neuroinflammation with neurodegeneration, since it's highly unlikely that immune dysregulation is the only factor that contributes to the manifestation of many of these neurodegenerative disorders. It is unquestionably a complex interaction with other factors such as genetics, age, and environment. This endorses the "multiple hit hypothesis". Consequently, if the host has a genetic susceptibility coupled to an age-related weakened immune system, this makes them more susceptible to the virus/bacteria-related infection. This may trigger the onset of chronic cytotoxic neuroinflammatory processes leading to protein dyshomeostasis and accumulation, and finally, these events lead to neuronal destruction. Here, we differentiate "neuroinflammation" and "inflammation" with regard to the involvement of the blood-brain barrier, which seems to be intact in the case of neuroinflammation but defect in the case of inflammation. There is a neuroinflammation-inflammation continuum with regard to virus-induced brain affection. Therefore, we propose a staging of this process, which might be further developed by adding blood- and CSF parameters, their stage-dependent composition and stage-dependent severeness grade. If so, this might be suitable to optimise therapeutic strategies to fight brain neuroinflammation in its beginning and avoid inflammation at all.

Does COVID-19 Trigger the Risk for the Development of Parkinson's Disease? Therapeutic Potential of Vitamin C

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which was proclaimed a pandemic by the World Health Organization (WHO) in March 2020. There is mounting evidence that older patients with multimorbidity are more susceptible to COVID-19 complications than are younger, healthy people. Having neuroinvasive potential, SARS-CoV-2 infection may increase susceptibility toward the development of Parkinson's disease (PD), a progressive neurodegenerative disorder with extensive motor deficits. PD is characterized by the aggregation of α-synuclein in the form of Lewy bodies and the loss of dopaminergic neurons in the dorsal striatum and substantia nigra pars compacta (SNpc) of the nigrostriatal pathway in the brain. Increasing reports suggest that SARS-CoV-2 infection is linked with the worsening of motor and non-motor symptoms with high rates of hospitalization and mortality in PD patients. Common pathological changes in both diseases involve oxidative stress, mitochondrial dysfunction, neuroinflammation, and neurodegeneration. COVID-19 exacerbates the damage ensuing from the dysregulation of those processes, furthering neurological complications, and increasing the severity of PD symptomatology. Phytochemicals have antioxidant, anti-inflammatory, and anti-apoptotic properties. Vitamin C supplementation is found to ameliorate the common pathological changes in both diseases to some extent. This review aims to present the available evidence on the association between COVID-19 and PD, and discusses the therapeutic potential of vitamin C for its better management.

SARS-CoV-2 and Parkinson's Disease: A Review of Where We Are Now

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has been discussed in the context of Parkinson's disease (PD) over the last three years. Now that we are entering the long-term phase of this pandemic, we are intrigued to look back and see how and why the community of patients with PD was impacted and what knowledge we have collected so far. The relationship between COVID-19 and PD is likely multifactorial in nature. Similar to other systemic infections, a probable worsening of PD symptoms secondary to COVID-19, either transient or persistent (long COVID), has been demonstrated, while the COVID-19-related mortality of PD patients may be increased compared to the general population. These observations could be attributed to direct or indirect damage from SARS-CoV-2 in the central nervous system (CNS) or could result from general infection-related parameters (e.g., hospitalization or drugs) and the sequelae of the COVID-19 pandemic (e.g., quarantine). A growing number of cases of new-onset parkinsonism or PD following SARS-CoV-2 infection have been reported, either closely (post-infectious) or remotely (para-infectious) after a COVID-19 diagnosis, although such a link remains hypothetical. The pathophysiological substrate of these phenomena remains elusive; however, research studies, particularly pathology studies, have suggested various COVID-19-induced degenerative changes with potential associations with PD/parkinsonism. We review the literature to date for answers considering the relationship between SARS-CoV-2 infection and PD/parkinsonism, examining pathophysiology, clinical manifestations, vaccination, and future directions.

Chorea following SARS-CoV-2 infection and vaccination: a systematic review of reported cases

OBJECTIVES

Chorea following SARS-CoV-2 infection and vaccination, has been increasingly recognized. We aimed to synthesize clinical and paraclinical characteristics, treatment responses, and outcomes of this neurologic complication.

METHODS

We systematically reviewed LitCOVID, the World Health Organization database on COVID-19, and MedRxiv up to March 2023, following a published protocol.

RESULTS

We included 14 chorea cases in patients with SARS-CoV-2 infection and eight following COVID-19 vaccination. Acute or subacute chorea preceded COVID-19 symptoms within 1-3 days or developed up to 3 months after infection. Frequently it was generalized (85.7%), with associated neurological manifestations (encephalopathy 35.7%; other movement disorders 7.1%). After vaccination, chorea had a sudden onset (87.5%) within 2 weeks (75%); 87.5% of cases presented hemichorea, with hemiballismus (37.5%) or other movement disorders; 12.5% presented additional neurological findings. Cerebrospinal fluid was normal in 50% of infected individuals but abnormal in all vaccinated cases. Brain magnetic resonance imaging detected normal basal ganglia in 51.7% of infection cases and 87.5% following vaccination.

CONCLUSION

In SARS-CoV-2 infection, chorea may present several pathogenic mechanisms: autoimmune response to infection, direct infection-related injury, or an infection-related complication (i.e., acute disseminated encephalomyelitis, cerebral venous sinus thrombosis, hyperglycemia); also, previous Sydenham chorea may relapse. After COVID-19 vaccination, chorea could be due to an autoimmune reaction or other mechanisms (vaccine-induced hyperglycemia, stroke).