Myoclonus and COVID-19: A Challenge for the Present, a Lesson for the Future

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.

COVID 19 and myoclonus, do hemodialysis patients have more risk?

We discuss two recent cases from our hospital in which two patients with ESKD receiving periodical hemodialysis (HD) and SarS-Cov-2 infection suffered movement disorders, being the onset related to the HD sessions in both. First case is a 78 year-old woman who is admitted with generalized myoclonic status epilepticus and second case is a 46 year-old male who starts repeatedly suffering myoclonus during his hemodialysis sessions on day +10 after testing positive (asymptomatic infection). There are two main hypotheses when it comes to myoclonus and CNS disorders in COVID19, post-hypoxic origin and inmunomediated postinfectious origin. We wonder if they could both be interacting in patients with kidney disease, and especially in those who receive hemodialysis, maximizing the risk of suffering this type of disorders.

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.

Relationship between COVID-19 and movement disorders: A narrative review

BACKGROUND AND PURPOSE

The scientific literature on COVID-19 is increasingly growing.

METHODS

In this paper, we review the literature on movement disorders in the context of the COVID-19 pandemic.

RESULTS

First, there are a variety of transient movement disorders that may manifest in the acute phase of COVID-19, most often myoclonus, with more than 50 patients described in the literature. New onset parkinsonism, chorea, and tic-like behaviours have also been reported. Movement disorders as a side effect after COVID-19 vaccination are rare, occurring with a frequency of 0.00002-0.0002 depending on the product used, mostly manifesting with tremor. Current evidence for potential long-term manifestations, for example, long COVID parkinsonism, is separately discussed. Second, the pandemic has also had an impact on patients with pre-existing movement disorder syndromes, with negative effects on clinical status and overall well-being, and reduced access to medication and health care. In many parts, the pandemic has led to reorganization of the medical system, including the development of new digital solutions. The movement disorder-related evidence for this is reviewed and discussed.

CONCLUSIONS

The pandemic and the associated preventive measures have had a negative impact on the clinical status, access to health care, and overall well-being of patients with pre-existing movement disorders.

[COVID 19 and myoclonus, do hemodialysis patients have more risk?]

We discuss two recent cases from our hospital in which two patients with ESKD receiving periodical hemodialysis (HD) and SarS-Cov-2 infection suffered movement disorders, being the onset related to the HD sessions in both. First case is a 78 year-old woman who is admitted with generalized myoclonic status epilepticus and second case is a 46 year-old male who starts repeatedly suffering myoclonus during his hemodialysis sessions on day +10 after testing positive (asymptomatic infection). There are two main hypotheses when it comes to myoclonus and CNS disorders in COVID19, post-hypoxic origin and inmunomediated postinfectious origin. We wonder if they could both be interacting in patients with kidney disease, and especially in those who receive hemodialysis, maximizing the risk of suffering this type of disorders.

Lance Adams Syndrome: A Rare Case Presentation of Myoclonus From Chronic Hypoxia Secondary to COVID-19 Infection

Coronavirus disease 2019 (COVID-19) pandemic is caused by the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) and since the outbreak, many neurological features and syndromes are reported with this multi-organ viral infection. Lance-Adams syndrome (LAS) also referred to as chronic post hypoxic myoclonus is defined as action myoclonus which can occur as generalized, focal, or multifocal repeated myoclonic motor movements which involve the face, trunk, or extremities and it is one of the neurological complications that are related to COVID-19 infection. LAS is reported as a delayed complication of cardiac arrest, which causes cerebral hypoxia leading to myoclonus. We report a case of a 58-year-old male patient diagnosed as a case of LAS secondary to hypoxia occurring because of COVID-19 without cardiac arrest and to the best of our knowledge it is the second case reported with this similar mechanism. Moreover, we discuss the possible pathophysiological relationship between LAS and COVID-19 and various treatment strategies. Eventually, we review the related articles in the literature regarding the LAS and various types of myoclonus associated with COVID-19 infection.

New-Onset Movement Disorders Associated with COVID-19

Introduction

Movement disorders are increasingly described in hospitalized and milder cases of SARS-CoV-2 infection, despite a very low prevalence compared to the total patients.

Methods

We reviewed the scientific literature published in English, spanning from the initial descriptions of COVID-19 until January 25, 2021, in the PubMed/MEDLINE database.

Results

We identified 93 new-onset movement disorders cases (44 articles) from 200 papers screened in the database or reference lists. Myoclonus was present in 63.4% (n = 59), ataxia in 38.7% (n = 36), action/postural tremor in 10.8% (n = 10), rigid-akinetic syndrome in 5.38% (n = 5), oculomotor abnormalities in 20.4% (n = 19), catatonia in 2.1% (n = 2), dystonia in 1.1% (n = 1), chorea in 1.1% (n = 1), functional (psychogenic) movement disorders in 3.2% (n = 3) of the reported COVID-19 cases with any movement disorder. Encephalopathy was a common association (n = 37, 39.78%).

Discussion

Comprehensive neurophysiological, clinical, and neuroimaging descriptions of movement disorders in the setting of SARS-CoV-2 infection are still lacking, and their pathophysiology may be related to inflammatory, postinfectious, or even indirect mechanisms not specific to SARS-CoV-2, such as ischemic-hypoxic brain insults, drug effects, sepsis, kidney failure. Cortical/subcortical myoclonus, which the cited secondary mechanisms can largely cause, seems to be the most common hyperkinetic abnormal movement, and it might occur in association with encephalopathy and ataxia.

Conclusion

This brief review contributes to the clinical description of SARS-CoV-2 potential neurological manifestations, assisting clinical neurologists in identifying features of these uncommon syndromes as a part of COVID-19 symptomatology.

Highlights

- Movement disorders are probably uncommon neurological manifestations in SARS-CoV-2 infection;- Myoclonus is the most reported movement disorder associated with COVID-19, its clinical complications or pharmacological management;- The pathophysiology is yet not well-understood but can include systemic inflammation, autoimmune mechanisms, or hypoxia.

Myoclonus and Cerebellar Ataxia Associated with SARS-CoV-2 Infection: Case Report and Review of the Literature

The current SARS-CoV-2/COVID-19 pandemic has led to a global health crisis. The clinical spectrum of SARS-CoV-2 infection ranges from asymptomatic infection to critical illness affecting almost every organ including the central and peripheral nervous systems. Myoclonus, a less expected and relatively unusual neurological complication, together with ataxia, has lately been associated with SARS-CoV-2 infection. We describe the case of a 67-year-old male patient, admitted to our hospital for interstitial bilateral pneumonia due to SARS-CoV-2 infection, who progressively developed general myoclonus and later cerebellar ataxia and gait disturbance. Given the timeline from COVID-19 systemic symptoms to neurological manifestations and the normal results of extensive and non-conclusive diagnostic work-up (blood test, lumbar puncture, EEG, cerebral MRI), a para-infectious encephalopathy related to SARS-CoV-2 was contemplated and a high dose of methylprednisolone was started with prompt symptom improvement. Further investigation and neuroepidemiological studies are needed to help define the mechanism of neuroinvasion and the entire spectrum of neurological manifestations of SARS-CoV-2 infection, even in mildly affected patients, in terms of prevention, treatment and possible neurological sequelae.

LEARNING POINTS

SARS-CoV-2 infection can be related to neurological symptoms and sequelae.Myoclonus, specifically when associated with ataxia, might represent the expression of COVID-19-related encephalopathy.Myoclonus associated with SARS-CoV-2 infection mostly responds to treatment with steroids.