Mixed central and peripheral nervous system disorders in severe SARS-CoV-2 infection

SARS-CoV-2 infection and cognition in community-dwelling and nursing home residents in southern Switzerland

Background

COVID-19 patients can report 'brain fog' and may exhibit cognitive symptoms for months after recovery (Cognitive COVID). However, evidence on whether and the extent to which SARS-CoV-2 infection impacts cognition irrespective of COVID-19 course and severity is limited to clinical samples and mainly comes from prognostic studies. We aimed to explore the association between serologically confirmed SARS-CoV-2 infection and cognitive functioning in community-based and institutionalized older adults, irrespective of COVID-19 symptoms.

Methods

We conducted a case-control study nested into two cohorts in Southern Switzerland. Eligible subjects were Italian speaking older adults, without a previous diagnosis of dementia, who underwent serological testing for anti-SARS-CoV-2 antibodies between November 2020 and July 2021. We manually selected age-, sex- and education-matched cases (i.e., individuals with a serologically confirmed SARS-CoV-2 infection), with seronegative controls, and we conducted in-person neuropsychological assessments using validated, highly sensitive cognitive tests.

Results

We completed 38 neuropsychological assessments in a mostly female sample of older adults (Mean age: 83.13 ± 8.95; 86.8% women). 17 were community dwelling individuals while 21 lived in a nursing home. As expected, socio-demographic characteristics of age, gender and educational level were similarly distributed between cases (n = 14) and controls (n = 24). In linear regression models, cases had significantly lower scores in cognitive tasks of memory (β = -0.367, p = 0.023), attention (β = 0.428, p = 0.008) and executive functions (β = 0.326, p = 0.046). We found no significant difference in tests of language and spatial-temporal orientation (all p values > 0.05).

Conclusions

SARS-CoV-2 infection was associated with cognitive impairment in memory, attention, and executive functions in older adults. Our findings are consistent with mechanistic evidence of the neurotropism of the virus and provide empirical support for the "Cognitive COVID" construct also in non-clinical samples. With nearly 800 million COVID-19 cases (in April 2023), and many more infections worldwide, the clinical and public health implications of Cognitive COVID due to SARS-CoV-2 infection may be massive and warrant further epidemiological investigations.

Prefrontal dysfunction in post-COVID-19 hyposmia: an EEG/fNIRS study

Introduction

Subtle cognitive dysfunction and mental fatigue are frequent after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, characterizing the so-called long COVID-19 syndrome. This study aimed to correlate cognitive, neurophysiological, and olfactory function in a group of subjects who experienced acute SARS-CoV-2 infection with persistent hyposmia at least 12 weeks before the observation.

Methods

For each participant (32 post-COVID-19 patients and 16 controls), electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) data were acquired using an integrated EEG-fNIRS system during the execution of a P300 odd-ball task and a Stroop test. The Sniffin' Sticks test was conducted to assess subjects' olfactory performance. The Montreal Cognitive Assessment (MoCA) and the Frontal Assessment Battery (FAB) were also administered.

Results

The post-COVID-19 group consisted of 32 individuals (20 women and 12 men) with an average education level of 12.9 ± 3.12 years, while the control group consisted of 16 individuals (10 women and 6 men) with an average education level of 14.9 ± 3.2 years. There were no significant differences in gender (X2 = 0, p = 1) or age between the two groups (age 44.81 ± 13.9 vs. 36.62 ± 11.4, p = 0.058). We identified a lower concentration of oxyhemoglobin (p < 0.05) at the prefrontal cortical level in post-COVID-19 subjects during the execution of the Stroop task, as well as a reduction in the amplitude of the P3a response. Moreover, we found that post-COVID-19 subjects performed worst at the MoCA screening test (p = 0.001), Sniffin's Sticks test (p < 0.001), and Stroop task response latency test (p < 0.001).

Conclusions

This study showed that post-COVID-19 patients with persistent hyposmia present mild deficits in prefrontal function, even 4 months after the end of the infection. These deficits, although subtle, could have long-term implications for quality of life and cognitive wellbeing. It is essential to continue monitoring and evaluating these patients to better understand the extent and duration of cognitive impairments associated with long COVID-19.

Uncovering a neurological protein signature for severe COVID-19

Coronavirus disease of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has sparked a global pandemic with severe complications and high morbidity rate. Neurological symptoms in COVID-19 patients, and neurological sequelae post COVID-19 recovery have been extensively reported. Yet, neurological molecular signature and signaling pathways that are affected in the central nervous system (CNS) of COVID-19 severe patients remain still unknown and need to be identified. Plasma samples from 49 severe COVID-19 patients, 50 mild COVID-19 patients, and 40 healthy controls were subjected to Olink proteomics analysis of 184 CNS-enriched proteins. By using a multi-approach bioinformatics analysis, we identified a 34-neurological protein signature for COVID-19 severity and unveiled dysregulated neurological pathways in severe cases. Here, we identified a new neurological protein signature for severe COVID-19 that was validated in different independent cohorts using blood and postmortem brain samples and shown to correlate with neurological diseases and pharmacological drugs. This protein signature could potentially aid the development of prognostic and diagnostic tools for neurological complications in post-COVID-19 convalescent patients with long term neurological sequelae.

Cerebrospinal fluid biomarkers in SARS-CoV-2 patients with acute neurological syndromes

BACKGROUND AND PURPOSE

Mechanisms underlying acute brain injury in SARS-CoV-2 patients remain poorly understood. A better characterization of such mechanisms remains essential to preventing long-term neurological sequelae. Our present aim was to study a panel of biomarkers of neuroinflammation and neurodegeneration in the cerebrospinal fluid (CSF) of NeuroCOVID patients.

METHODS

We retrospectively collected clinical and CSF biomarkers data from 24 NeuroCOVID adults seen at the University Hospital of Guadeloupe between March and June 2021.

RESULTS

Among 24 NeuroCOVID patients, 71% had encephalopathy and 29% meningoencephalitis. A number of these patients also experienced de novo movement disorder (33%) or stroke (21%). The CSF analysis revealed intrathecal immunoglobulin synthesis in 54% of NeuroCOVID patients (two with a type 2 pattern and 11 with a type 3) and elevated neopterin levels in 75% of them (median 9.1nM, IQR 5.6-22.1). CSF neurofilament light chain (NfL) was also increased compared to a control group of non-COVID-19 patients with psychiatric illnesses (2905ng/L, IQR 1428-7124 versus 1222ng/L, IQR 1049-1566). Total-tau was elevated in the CSF of 24% of patients, whereas protein 14-3-3, generally undetectable, reached intermediate levels in two patients. Finally, CSF Aß1-42 was reduced in 52.4% of patients (median 536ng/L, IQR 432-904) with no change in the Aß1-42/Aß1-40 ratio (0.082, IQR 0.060-0.096).

CONCLUSIONS

We showed an elevation of CSF biomarkers of neuroinflammation in NeuroCOVID patients and a rise of CSF NfL, evocative of neuronal damage. However, longitudinal studies are needed to determine whether NeuroCOVID could evolve into a chronic neurodegenerative condition.

Late peripheral facial paralysis after COVID-19: a rapid systematic review and two case reports

Peripheral facial paralysis (PFP) has been shown to be a neurological manifestation of COVID-19. The current study presents two cases of PFP after COVID-19, along with a rapid review of known cases in the literature. Both case reports were conducted following CARE guidelines. We also performed a systematic review of PFP cases temporally related to COVID-19 using PubMed, Embase, and Cochrane Library databases on August 30, 2021, using a rapid review methodology. The two patients experienced PFP 102 and 110 days after COVID-19 symptom onset. SARS-CoV-2 RNA was detected in nasal samples through reverse-transcription real-time polymerase chain reaction (RT-qPCR) testing. Anosmia was the only other neurological manifestation. PFP was treated with steroids in both cases, with complete subsequent recovery. In the rapid review, we identified 764 articles and included 43 studies. From those, 128 patients with PFP were analyzed, of whom 42.1% (54/128) were male, 39.06% (50/128) female, and in 23 cases the gender was not reported. The age range was 18 to 59 (54.68%). The median time between COVID-19 and PFP was three days (ranging from the first symptom of COVID-19 to 40 days after the acute phase of infection). Late PFP associated with COVID-19 presents mild symptoms and improves with time, with no identified predictors. Late PFP should be added to the spectrum of neurological manifestations associated with the long-term effects of SARS-CoV-2 infection as a post COVID-19 condition.

Facial Nerve Paralysis and COVID-19: A Systematic Review

Objective

Several cases of facial nerve paralysis (FNP) post‐COVID‐19 infection have been reported with varying presentations and management. This study aims to identify FNP clinical characteristics and recovery outcomes among patients acutely infected with COVID‐19. We hypothesize that FNP is a potentially unique sequalae associated with COVID‐19 infections.

Methods

A systematic review of PubMed‐Medline, OVID Embase, and Web of Science databases from inception to November 2021 was conducted following the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines.

Results

This search identified 630 studies with 53 meeting inclusion criteria. This resulted in 72 patients, of which 30 (42%) were diagnosed with Guillain‐Barré Syndrome (GBS). Non‐GBS patients were on average younger (36 vs. 53 years) and more likely to present with unilateral FNP (88%) compared to GBS patients who presented predominantly with bilateral FNP (74%). Among non‐GBS patients, majority (70%) of FNP presented a median of 8 [IQR 10] days after the onset of initial COVID‐19 symptom(s). Treatment for non‐GBS patients consisted of steroids (60%), antivirals (29%), antibiotics (21%), and no treatment (21%). Complete FNP recovery in non‐GBS patients was achieved in 67% patients within a median of 11 [IQR 24] days.

Conclusion

FNP is a possible presentation post COVID‐19 infections, associated with both GBS and non‐GBS patients. Although no causation can be assumed, the clinical course of isolated FNP associated with COVID‐19 raises the possibility of a unique presentation differing from Bell's palsy, seen with higher proportion of patients developing bilateral FNP and a shorter duration to complete recovery. Laryngoscope, 2022

Temporal Changes in Brain Perfusion in a Patient with Myoclonus and Ataxia Syndrome Associated with COVID-19

Myoclonus and ataxia, with or without opsoclonus, have recently been recognized as a central nervous system syndrome associated with coronavirus disease-2019 (COVID-19). A 52-year-old Japanese man developed myoclonus and ataxia 16 days after the onset of COVID-19. Brain single-photon emission computed tomography (SPECT) revealed hyperperfusion in the cerebellum and hypoperfusion in the cerebral cortices with frontal predominance during the acute stage, which improved over two months. This study indicates that brain perfusion SPECT can be effective in detecting functional alterations in COVID-19-related myoclonus and ataxia.

Cognitive, emotional-affective, anxiety and autonomic disorders in patients with a new coronavirus infection (covid-19) in the acute period

The purpose of this work is to identify neuropsychiatric functions in patients at Department No. 1 responsible for medical care of patients with a new coronavirus infection at the Samara City Hospital No. 7. Appropriate scales and questionnaires were used for this purpose. Cognitive impairments were found in 86% of the cases, emotional-affective impairments of varying severity in half of the subjects, an increase in reactive and personal anxiety was revealed, and vegetative disorders were observed in 78% of the subjects. Based on these data, it can be assumed that the new coronavirus infection affects the functioning of the nervous system of patients.

Eye Movement Alterations in Post-COVID-19 Condition: A Proof-of-Concept Study

There is much evidence pointing out eye movement alterations in several neurological diseases. To the best of our knowledge, this is the first video-oculography study describing potential alterations of eye movements in the post-COVID-19 condition. Visually guided saccades, memory-guided saccades, and antisaccades in horizontal axis were measured. In all visual tests, the stimulus was deployed with a gap condition. The duration of the test was between 5 and 7 min per participant. A group of n=9 patients with the post-COVID-19 condition was included in this study. Values were compared with a group (n=9) of healthy volunteers whom the SARS-CoV-2 virus had not infected. Features such as centripetal and centrifugal latencies, success rates in memory saccades, antisaccades, and blinks were computed. We found that patients with the post-COVID-19 condition had eye movement alterations mainly in centripetal latency in visually guided saccades, the success rate in memory-guided saccade test, latency in antisaccades, and its standard deviation, which suggests the involvement of frontoparietal networks. Further work is required to understand these eye movements' alterations and their functional consequences.

Focal Peripheral Neuropathies Observed in Patients Diagnosed With COVID-19: A Case Series

ABSTRACT

A growing number of studies have documented a wide variety of neurological manifestations associated with the novel SARS-CoV-2 (COVID-19). Of the available literature, cranial neuropathies and central nervous system disorders, such as encephalopathy and ischemic strokes, remain the predominant discussion. Limited investigations exist examining peripheral neuropathies of those with COVID-19. This case series discusses eight patients who tested positive for COVID-19 and presented with localized weakness after a prolonged course of mechanical ventilation (>21 days). We retrospectively reviewed all patients' charts who received electrodiagnostic evaluation between March and November 2020 in the outpatient clinic or in the acute care hospital at the JFK Medical Center/JFK Johnson Rehabilitation Institute and Saint Peter's University Hospital of New Jersey. A total of eight COVID-19-positive patients were identified to have a clinical presentation of localized weakness after a prolonged course of mechanical ventilation. All patients were subsequently found to have a focal peripheral neuropathy of varying severity that was confirmed by electrodiagnostic testing. Patient demographics, clinical, and electrodiagnostic findings were documented. The findings of local weakness and focal peripheral neuropathies after diagnosis of COVID-19 raise significant questions regarding underlying pathophysiology and overall prognosis associated with COVID-19.

Long-term outcomes after NeuroCOVID: A 6-month follow-up study on 60 patients

BACKGROUND AND PURPOSE

Long-term outcomes after neurological manifestations due to COVID-19 are poorly known. The aim of our study was to evaluate the functional outcome and identify the risk factors of neurologic sequelae after COVID-19 associated with neurological manifestations (NeuroCOVID).

METHODS

We conducted a multi-center observational study six months after the acute neurological symptoms in patients from the French NeuroCOVID hospital-based registry.

RESULTS

We obtained data on 60 patients. NeuroCOVID had a negative impact on the quality of life (QoL) of 49% of patients. Age was a predictor of residual QoL impairment (OR: 1.06, 95% CI: 1.01-1.13, p=0.026). At six months, a significant residual disability was found in 51.7% of patients, and impaired cognition in 68.9% of cases. The main persistent neuropsychiatric manifestations were a persistent smell/taste disorder in 45% of patients, memory complaints in 34% of patients, anxiety or depression in 32% of patients.

CONCLUSIONS

NeuroCOVID likely carries a high risk of long-term neuropsychiatric disability. Long-term care and special attention should be given to COVID-19 patients, especially if they had neurological manifestations during acute infection.

COVID-19, the Brain, and the Future: Is Infection by the Novel Coronavirus a Harbinger of Neurodegeneration?

The possible impact of viral infections on the development or pathogenesis of neurodegenerative disorders remains largely unknown. However, there have been reports associating the influenza virus pandemic and long-term infection with the Japanese encephalitis virus with the development of post-encephalitic Parkinsonism or von Economo encephalitis. In the last one year plus, there has been a worldwide pandemic arising from infection with the novel coronavirus or severe acute respiratory syndrome coronavirus (SARS-CoV)-2 which causes a severe acute respiratory syndrome that has become associated with central nervous system symptoms or complications. Its possible central nervous system involvement is in line with emerging scientific evidence which shows that the human respiratory coronaviruses can enter the brain, infect neural cells, persist in the brain, and cause activation of myelin-reactive T cells. Currently, there is a dearth of scientific information on the acute or possible long-term impact of infection with SARS-CoV-2 on the development of dementias and/or neurodegenerative diseases. This is not unrelated to the fact that the virus is 'new', and its effects on humans are still being studied. This narrative review examines extant literature for the impact of corona virus infections on the brain; as it considers the possibility that coronavirus disease 2019 (COVID-19) could increase the risk for the development of neurodegenerative diseases or hasten their progression.

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.

[Neurological Manifestations of COVID-19]

After first reports of a new predominantely respiratory illness detected in Wuhan City, Hubei Province of China in Dezember 2019, the novel coronavirus SARS-CoV-2 rapidly spreads all over China and the world. Growing evidence suggests that neurological signs, symptoms and complications occur during the course of the COVID-19 disease. This article highlights neurological aspects of COVID-19 and also discusses the impact of the COVID-19 pandemic on patients with Parkinson's disease.

Movement Disorders Associated with COVID-19

As neurological complications associated with COVID-19 keep unfolding, the number of cases with COVID-19-associated de novo movement disorders is rising. Although no clear pathomechanistic explanation is provided yet, the growing number of these cases is somewhat alarming. This review gathers information from 64 reports of de novo movement disorders developing after/during infection with SARS-CoV-2. Three new cases with myoclonus occurring shortly after a COVID-19 infection are also presented. Treatment resulted in partial to complete recovery in all three cases. Although the overall percentage of COVID-19 patients who develop movement disorders is marginal, explanations on a probable causal link have been suggested by numerous reports; most commonly involving immune-mediated and postinfectious and less frequently hypoxic-associated and ischemic-related pathways. The current body of evidence points myoclonus and ataxia out as the most frequent movement disorders occurring in COVID-19 patients. Some cases of tremor, chorea, and hypokinetic-rigid syndrome have also been observed in association with COVID-19. In particular, parkinsonism may be of dual concern in the setting of COVID-19; some have linked viral infections with Parkinson's disease (PD) based on results from cerebrospinal fluid analyses, and PD is speculated to impact the outcome of COVID-19 in patients negatively. In conclusion, the present paper reviewed the demographic, clinical, and treatment-associated information on de novo movement disorders in COVID-19 patients in detail; it also underlined the higher incidence of myoclonus and ataxia associated with COVID-19 than other movement disorders.

Neurological update: COVID-19

Coronavirus Disease 2019 is predominantly a disorder of the respiratory system, but neurological complications have been recognised since early in the pandemic. The major pathophysiological processes leading to neurological damage in COVID-19 are cerebrovascular disease, immunologically mediated neurological disorders and the detrimental effects of critical illness on the nervous system. It is still unclear whether direct invasion of the nervous system by the Severe Acute Respiratory Syndrome Coronavirus 2 occurs; given the vast numbers of people infected at this point, this uncertainty suggests that nervous system infection is unlikely to represent a significant issue if it occurs at all. In this review, we explore what has been learnt about the neurological complications of COVID-19 over the course of the pandemic, and by which mechanisms these complications most commonly occur.

COVID-19 Peripheral Neuropathy: A Report of Three Cases

This study includes three patients with various peripheral neuropathies after contracting coronavirus disease 2019 (COVID-19) infection, treated both conservatively and surgically. While cases of neurological complications have been described, neuropathy associated with COVID-19 is under-reported in orthopaedic literature. These patients presented with ulnar neuropathy, critical care polyneuropathy (CCP) with anterior interosseous nerve (AIN) neuropathy, and lateral femoral cutaneous nerve (LFCN) neuropathy. COVID-19 infection may be associated with peripheral neuropathy in addition to various neurological sequelae. Orthopaedic surgeons should screen patients for recent infections and evaluate the severity of the illness to assess for risk of neurological sequelae of COVID-19 infection.

Neurological manifestations in mild and moderate cases of COVID-19

Background

The coronavirus disease due to SARS COVID-2 emerged from Wuhan city in China in December 2019 and rapidly spread to more than 200 countries all over the world as a global health pandemic. Its primary presentation is respiratory and cardiac. However, some neurological manifestations are also reported. We tried to explore the reported neurological manifestations in a group of non-hospitalized mild and moderate COVID-19 patients. We contacted 107 patients via phone calls and e-mail messages, within 10 days of clinical presentation. The collected data regarded the neurological and non-neurological symptoms of the disease using a questionnaire that collected medical information of each patient.

Results

It is found that 100% of patients have been reported with at least one neurological symptom during the first 10 days of COVID-19 presentation. The most common were headache which recorded 72% of the total. Then anosmia–dysgeusia which reached 52%, then myalgia with 44%, fatigue with 33% and dizziness with 32%. While the less common was numbness, migraine, loss of concentration, and seizures.

Conclusion

There are many neurological manifestations found to be very common in COVID-19 patients even in mild cases, which when added to the increasing reports of serious cases of Guillain–Barre syndrome, acute necrotizing encephalopathy, myelitis, stroke, and encephalitis in COVID-19 patients support CNS invasion of the virus and assures the importance of neurological assessment of COVID-19 patients both in the acute phase of infection and after recovery for potential neurological sequelae.

Age-Associated Neurological Complications of COVID-19: A Systematic Review and Meta-Analysis

The outbreak of the novel and highly infectious severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in hundreds of millions of infections and millions of deaths globally. Infected individuals that progress to coronavirus disease-19 (COVID-19) experience upper and lower respiratory complications that range in severity and may lead to wide-spread inflammation and generalized hypoxia or hypoxemia that impacts multiple organ systems, including the central and peripheral nervous systems. Since the SARS-CoV-2 outbreak, multiple reports continue to emerge that detail neurological symptoms, ranging from relatively mild (e.g., impaired taste and/or smell) to severe (e.g., stroke), suggesting SARS-CoV-2 may be neurotropic and/or contribute to nervous system injury through direct and/or indirect mechanisms. To gain insight into the types of neurological complications associated with SARS-CoV-2 infection and their possible relationship with age, sex, COVID-19 severity, and comorbidities, we performed a systematic review of case reports and series published in 2020 - April 4, 2021 of infected patients with neurological manifestations. Meta-analyses were conducted using individual patient data from reports where these data could be extracted. Here, we report neurological injury occurs across the lifespan in the context of infection, with and without known comorbidities, and with all disease severities, including asymptomatic patients. Older individuals, however, are more susceptible to developing life-threatening COVID-19 and cerebrovascular disease (CVD), such as stroke. A mild but inverse correlation with age was seen with CNS inflammatory diseases, such as encephalitis, as well as taste and/or smell disorders. When reported, increased age was also associated with comorbid cardiovascular risk factors, including hypertension, diabetes mellitus, and lipid disorders, but not with obesity. Obesity did correlate with development of critical COVID-19. Discussion into potential pathophysiological mechanisms by which neurological symptoms arise and long-term consequences of infection to the nervous system is also provided.

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.

De Novo Movement Disorders and COVID-19: Exploring the Interface

Background

Neurological manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being widely documented. However, movement disorders in the setting of 2019 coronavirus infectious disease (COVID-19) have been a strikingly less discussed topic.

Objectives

To summarize available pieces of evidence documenting de novo movement disorders in COVID-19.

Methods

We used the existing PRISMA consensus statement. Data were collected from PubMed, EMBASE, Web of Science, and Scopus databases up to the 29th January, 2021, using pre-specified searching strategies.

Results

Twenty-two articles were selected for the qualitative synthesis. Among these, a total of 52 patients with de novo movement disorders were reported. Most of these had myoclonus, ataxia, tremor or a combination of these, while three had parkinsonism and one a functional disorder. In general, they were managed successfully by intravenous immunoglobulin or steroids. Some cases, primarily with myoclonus, could be ascribed to medication exposures, metabolic disturbances or severe hypoxia, meanwhile others to a post-or para-infectious immune-mediated mechanism. SARS-CoV-2 could also invade the central nervous system, through vascular or retrograde axonal pathways, and cause movement disorders by two primary mechanisms. Firstly, through the downregulation of angiotensin-converting enzyme 2 receptors, resulting in the imbalance of dopamine and norepinephrine; and secondly, the virus could cause cellular vacuolation, demyelination and gliosis, leading to encephalitis and associated movement disorders.

Conclusion

De novo movement disorders are scantly reported in COVID-19. The links between SARS-CoV-2 and movement disorders are not yet established. However, we should closely monitor COVID-19 survivors for the possibility of post-COVID movement disorders.

Divulging the Intricacies of Crosstalk Between NF-Kb and Nrf2-Keap1 Pathway in Neurological Complications of COVID-19

The severity of COVID-19 infection is surging day by day. With the cases increasing daily, it is becoming more and more essential to understand the pathogenic mechanisms underlying the severity of the disease. It is now well known that the infection manifests itself primarily as respiratory, but the involvement of the other organ systems has now been documented in many studies. SARS-CoV-2 can invade the nervous system by a multitude of proposed mechanisms that have been discussed in this review. NF-κB and Nrf2 are transcription factors that regulate genes responsible for inflammatory and anti-oxidant response respectively. Specific focus in this review has been given to NF-κB and Nrf2 pathways that are involved in the cytokine storm and oxidative stress that are the hallmarks of COVID-19. As the immune injury is an important mechanism of neuro-invasion and neuroinflammation, there is the possible involvement of these two pathways in the neurological complications. The crosstalk mechanisms of these signaling pathways have also been discussed. Immuno-modulators both synthetic and natural are promising candidates in catering to the pathologies targeted in the aforementioned pathways.

Back to the future: lessons from past viral infections and the link with Parkinson's disease

During the current coronavirus disease 2019 (COVID-19) pandemic, there has been noticeable increase in the reporting of neurological symptoms in patients. There is still uncertainty around the significance and long-term consequence of these symptoms. There are also many outstanding questions on whether the causative virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) can directly infect the central nervous system (CNS). Given the long association between viral infections with neurodegenerative conditions such as Parkinson's disease (PD), it seems timely to review this literature again in the context of the COVID-19 pandemic and to glean some useful information from studies on similar viruses. In this commentary, we will consider the current knowledge on viral infections in the brain. In addition, we review the link between viral infection and neurodegeneration in PD, and review the recent literature on SARS infections, the potential link with PD and the potential areas of study in the future.

Clinical Manifestation, Evaluation, and Rehabilitative Strategy of Dysphagia Associated With COVID-19

ABSTRACT

Dysphagia is the difficulty in swallowing because of the presence of certain diseases; it particularly compromises the oral and/or pharyngeal stages. In severe acute respiratory syndrome coronavirus 2 infection, neuromuscular complications, prolonged bed rest, and endotracheal intubation target different levels of the swallowing network. Thus, critically ill patients are prone to dysphagia and aspiration pneumonia. In this review, we first discuss the possible cause and pathophysiology underlying dysphagia associated with coronavirus disease 2019, including cerebrovascular events, such as stroke, encephalomyelitis, encephalopathy, peripheral neuropathy, and myositis, that may lead to the dysphagia reported as a complication associated with the coronavirus disease 2019. Next, we present some recommendations for dysphagia evaluation with modifications that would allow a safe and comprehensive assessment based on available evidence to date, including critical considerations of the appropriate use of personal protective equipment and optimization individual's noninstrumental swallowing tasks evaluation, while preserving instrumental assessments for urgent cases only. Finally, we discuss a practical managing strategy for dysphagia rehabilitation to ensure safe and efficient practice in the risks of severe acute respiratory syndrome coronavirus 2 exposure, in which swallowing therapy using newer technology, such as telerehabilitation system or wearable device, would be considered as a useful option.

Cognitive and behavioral manifestations in SARS-CoV-2 infection: not specific or distinctive features?

Patients with COVID-19 are increasingly reported to suffer from a wide range of neurological complications, affecting both the central and peripheral nervous system. Among central manifestations, cognitive and behavioral symptoms are to date not exhaustively detailed. Furthermore, it is not clear whether these represent a combination of non-specific complications of a severe systemic disease, not differing from those usually seen in patients suffering from heterogenous pathological conditions affecting the central nervous system, or instead, they are a peculiar expression of COVID-19 neurotropism; in other words, if the infection has a coincidental or causal role in such patients. We examined both hypotheses, reporting opposite points of view, with the aim to stimulate discussion and raise awareness of the topic.

Clinical and Pathophysiologic Spectrum of Neuro-COVID

Though the lungs are predominantly affected in SARS-CoV-2-infected patients, extra-pulmonary manifestations can occur. Extra-pulmonary manifestations of the central and peripheral nervous system need to be recognised as they can strongly determine the outcome. This mini-review summarises and discusses previous and recent findings about neuro-COVID. The spectrum of central nervous system disease in COVID-19 patients is much broader than so far anticipated. Peripheral nerves and the skeletal muscle are less predominantly affected. In the vast majority of the cases, there is no direct attack of the virus towards vulnerable structures, which explains why various manifestations of the nervous system manifest favourably to immune suppression or immune modulation. Overall, the pathophysiology and clinical presentation of CNS/PNS involvement in COVID-19 is wider than believed. All patients with COVID-19 should be investigated by the neurologist for primary or secondary involvement of the CNS/PNS in the infection. neuro-COVID responds favourably to immune suppressants or immune modulation.

Brain dysfunction in COVID-19 and CAR-T therapy: cytokine storm-associated encephalopathy

OBJECTIVE

Many neurological manifestations are associated with COVID-19, including a distinct form of encephalopathy related to cytokine storm, the acute systemic inflammatory syndrome present in a subgroup of COVID-19 patients. Cytokine storm is also associated with immune effector cell-associated neurotoxicity syndrome (ICANS), a complication of chimeric antigen receptor T-cell (CAR-T) therapy, a highly effective treatment for refractory hematological malignancies. We investigated whether COVID-19-related encephalopathy, ICANS, and other encephalopathies associated with cytokine storm, share clinical and investigative findings.

METHODS

Narrative literature review.

RESULTS

Comparisons between COVID-19-related encephalopathy and ICANS revealed several overlapping features. Clinically, these included dysexecutive syndrome, language disturbances, akinetic mutism and delirium. EEG showed a prevalence of frontal abnormalities. Brain MRI was often unrevealing. CSF elevated cytokine levels have been reported. A direct correlation between cytokine storm intensity and severity of neurological manifestations has been shown for both conditions. Clinical recovery occurred spontaneously or following immunotherapies in most of the patients. Similar clinical and investigative features were also reported in other encephalopathies associated with cytokine storm, such as hemophagocytic lymphohistiocytosis, sepsis, and febrile infection-associated encephalopathies.

INTERPRETATION

COVID-19-related encephalopathy and ICANS are characterized by a predominant electro-clinical frontal lobe dysfunction and share several features with other encephalopathies associated with cytokine storm, which may represent the common denominator of a clinical spectrum of neurological disorders. Therefore, we propose a unifying definition of cytokine storm-associated encephalopathy (CySE), and its diagnostic criteria.

Subacute cerebellar ataxia following respiratory symptoms of COVID-19: a case report

Background

Severe acute respiratory syndrome virus 2 (SARS-CoV-2) is spreading globally and causes most frequently fever and respiratory symptoms, i.e. Coronavirus disease 2019 (COVID-19), however, distinct neurological syndromes associated with SARS-CoV-2 infection have been described. Among SARS-CoV-2-infections-associated neurological symptoms fatigue, headache, dizziness, impaired consciousness and anosmia/ageusia are most frequent, but less frequent neurological deficits such as seizures, Guillain-Barré syndrome or ataxia may also occur.

Case presentation

Herein we present a case of a 62-year-old man who developed a subacute cerebellar syndrome with limb-, truncal- and gait ataxia and scanning speech 1 day after clinical resolution of symptomatic SARS-CoV-2 infection of the upper airways. Apart from ataxia, there were no signs indicative of opsoclonus myoclonus ataxia syndrome or Miller Fisher syndrome. Cerebral magnetic resonance imaging showed mild cerebellar atrophy. SARS-CoV-2 infection of the cerebellum was excluded by normal cerebrospinal fluid cell counts and, most importantly, absence of SARS-CoV-2 RNA or intrathecal SARS-CoV-2-specific antibody production. Other causes of ataxia such as other viral infections, other autoimmune and/or paraneoplastic diseases or intoxication were ruled out. The neurological deficits improved rapidly after high-dose methylprednisolone therapy.

Conclusions

The laboratory and clinical findings as well as the marked improvement after high-dose methylprednisolone therapy suggest a post-infectious, immune-mediated cause of ataxia. This report should make clinicians aware to consider SARS-CoV-2 infection as a potential cause of post-infectious neurological deficits with an atypical clinical presentation and to consider high-dose corticosteroid treatment in case that a post-infectious immune-mediated mechanism is assumed.

Myoclonus and cerebellar ataxia associated with COVID-19: a case report and systematic review

Background

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic in December 2019, neurological manifestations have been recognized as potential complications. Relatively rare movement disorders associated with COVID-19 are increasingly reported in case reports or case series. Here, we present a case and systematic review of myoclonus and cerebellar ataxia associated with COVID-19.

Methods

A systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline using the PubMed and Ovid MEDLINE databases, from November 1, 2019 to December 6, 2020.

Results

51 cases of myoclonus or ataxia associated with COVID-19, including our case, were identified from 32 publications. The mean age was 59.6 years, ranging from 26 to 88 years, and 21.6% were female. Myoclonus was multifocal or generalized and had an acute onset, usually within 1 month of COVID-19 symptoms. Myoclonus occurred in isolation (46.7%), or with ataxia (40.0%) or cognitive changes (30.0%). Most cases improved within 2 months, and treatment included anti-epileptic medications or immunotherapy. Ataxia had an acute onset, usually within 1 month of COVID-19 symptoms, but could be an initial symptom. Concurrent neurological symptoms included cognitive changes (45.5%), myoclonus (36.4%), or a Miller Fisher syndrome variant (21.2%). Most cases improved within 2 months, either spontaneously or with immunotherapy.

Conclusions

This systematic review highlights myoclonus and ataxia as rare and treatable post-infectious or para-infectious, immune-mediated phenomena associated with COVID-19. The natural history is unknown and future investigation is needed to further characterize these movement disorders and COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10458-0.

COVID-19-Associated Neurological Manifestations: An Emerging Electroencephalographic Literature

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide since the end of year 2019 and is currently responsive for coronavirus infectious disease 2019 (COVID-19). The first reports considered COVID-19 as a respiratory tract disease responsible for pneumonia, but numerous studies rapidly emerged to warn the medical community of COVID-19-associated neurological manifestations, including encephalopathy at the acute phase and other postinfectious manifestations. Using standard visual analysis or spectral analysis, recent studies reported electroencephalographic (EEG) findings of COVID-19 patients with various neurological symptoms. Most EEG recordings were normal or revealed non-specific abnormalities, such as focal or generalized slowing, interictal epileptic figures, seizures, or status epilepticus. Interestingly, novel EEG abnormalities over frontal areas were also described at the acute phase. Underlying mechanisms leading to brain injury in COVID-19 are still unknown and matters of debate. These frontal EEG abnormalities could emphasize the hypothesis whereby SARS-CoV-2 enters the central nervous system (CNS) through olfactory structures and then spreads in CNS via frontal lobes. This hypothesis is reinforced by the presence of anosmia in a significant proportion of COVID-19 patients and by neuroimaging studies confirming orbitofrontal abnormalities. COVID-19 represents a new viral disease characterized by not only respiratory symptoms but also a systemic invasion associated with extra-respiratory signs. Neurological symptoms must be the focus of our attention, and functional brain evaluation with EEG is crucial, in combination with anatomical and functional brain imaging, to better understand its pathophysiology. Evolution of symptoms together with EEG patterns at the distance of the acute episode should also be scrutinized.

Opsoclonus-myoclonus syndrome, a post-infectious neurologic complication of COVID-19: case series and review of literature

Opsoclonus-myoclonus-ataxia syndrome is a heterogeneous constellation of symptoms ranging from full combination of these three neurological findings to varying degrees of isolated individual sign. Since the emergence of coronavirus disease 2019 (COVID-19), neurological symptoms, syndromes, and complications associated with this multi-organ viral infection have been reported and the various aspects of neurological involvement are increasingly uncovered. As a neuro-inflammatory disorder, one would expect to observe opsoclonus-myoclonus syndrome after a prevalent viral infection in a pandemic scale, as it has been the case for many other neuro-inflammatory syndromes. We report seven cases of opsoclonus-myoclonus syndrome presumably parainfectious in nature and discuss their phenomenology, their possible pathophysiological relationship to COVID-19, and diagnostic and treatment strategy in each case. Finally, we review the relevant data in the literature regarding the opsoclonus-myoclonus syndrome and possible similar cases associated with COVID-19 and its diagnostic importance for clinicians in various fields of medicine encountering COVID-19 patients and its complications.

Cognitive and Neuropsychiatric Manifestations of COVID-19 and Effects on Elderly Individuals With Dementia

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide and has had unprecedented effects in healthcare systems, economies and society. COVID-19 clinical presentation primarily affects the respiratory system causing bilateral pneumonia, but it is increasingly being recognized as a systemic disease, with neurologic manifestations reported in patients with mild symptoms but, most frequently, in those in a severe condition. Elderly individuals are at high risk of developing severe forms of COVID-19 due to factors associated with aging and a higher prevalence of medical comorbidities and, therefore, they are more vulnerable to possible lasting neuropsychiatric and cognitive impairments. Several reports have described insomnia, depressed mood, anxiety, post-traumatic stress disorder and cognitive impairment in a proportion of patients after discharge from the hospital. The potential mechanisms underlying these symptoms are not fully understood but are probably multifactorial, involving direct neurotrophic effect of SARS-CoV-2, consequences of long intensive care unit stays, the use of mechanical ventilation and sedative drugs, brain hypoxia, systemic inflammation, secondary effects of medications used to treat COVID-19 and dysfunction of peripheral organs. Chronic diseases such as dementia are a particular concern not only because they are associated with higher rates of hospitalization and mortality but also because COVID-19 further exacerbates the vulnerability of those with cognitive impairment. In patients with dementia, COVID-19 frequently has an atypical presentation with mental status changes complicating the early identification of cases. COVID-19 has had a dramatical impact in long-term care facilities, where rates of infection and mortality have been very high. Community measures implemented to slow the spread of the virus have forced to social distancing and cancelation of cognitive stimulation programs, which may have contributed to generate loneliness, behavioral symptoms and worsening of cognition in patients with dementia. COVID-19 has impacted the functioning of Memory Clinics, research programs and clinical trials in the Alzheimer’s field, triggering the implementation of telemedicine. COVID-19 survivors should be periodically evaluated with comprehensive cognitive and neuropsychiatric assessments, and specific mental health and cognitive rehabilitation programs should be provided for those suffering long-term cognitive and psychiatric sequelae.

Intravenous immunoglobulin therapy in COVID-19-related encephalopathy

Objective

To report on efficacy and safety of intravenous immunoglobulin (IVIg) therapy in a case series of patients with COVID-19-related encephalopathy.

Methods

We retrospectively collected data on all patients with COVID-19 hospitalized at two Italian hospitals who developed encephalopathy during disease course and were treated with IVIg.

Results

Five patients (two females, mean age 66.8 years) developed encephalopathy after a mean of 12.6 days, since the onset of respiratory/constitutional symptoms related to COVID-19. Four patients suffered severe respiratory distress, three of which required invasive mechanical ventilation. Neurological manifestations included impaired consciousness, agitation, delirium, pyramidal and extrapyramidal signs. EEG demonstrated diffuse slowing in all patients. Brain MRI showed non-specific findings. CSF analysis revealed normal cell count and protein levels. In all subjects, RT-PCR for SARS-CoV-2 in CSF tested negative. IVIg at 0.4 g/kg/die was commenced 29.8 days (mean, range: 19–55 days) after encephalopathy onset, leading to complete electroclinical recovery in all patients, with an initial improvement of neuropsychiatric symptoms observed in 3.4 days (mean, range: 1–10 days). No adverse events related to IVIg were observed.

Conclusions

Our preliminary findings suggest that IVIg may represent a safe and effective treatment for COVID-19-associated encephalopathy. Clinical efficacy may be driven by the anti-inflammatory action of IVIg, associated with its anti-cytokine qualities.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10248-0) contains supplementary material, which is available to authorized users.

Neuromuscular presentations in patients with COVID-19

COVID-19 is caused by the coronavirus SARS-CoV-2 that has an affinity for neural tissue. There are reports of encephalitis, encephalopathy, cranial neuropathy, Guillain-Barrè syndrome, and myositis/rhabdomyolysis in patients with COVID-19. In this review, we focused on the neuromuscular manifestations of SARS-CoV-2 infection. We analyzed all published reports on SARS-CoV-2-related peripheral nerve, neuromuscular junction, muscle, and cranial nerve disorders. Olfactory and gustatory dysfunction is now accepted as an early manifestation of COVID-19 infection. Inflammation, edema, and axonal damage of olfactory bulb have been shown in autopsy of patients who died of COVID-19. Olfactory pathway is suggested as a portal of entry of SARS-CoV-2 in the brain. Similar to involvement of olfactory bulb, isolated oculomotor, trochlear and facial nerve has been described. Increasing reports Guillain-Barrè syndrome secondary to COVID-19 are being published. Unlike typical GBS, most of COVID-19-related GBS were elderly, had concomitant pneumonia or ARDS, more prevalent demyelinating neuropathy, and relatively poor outcome. Myalgia is described among the common symptoms of COVID-19 after fever, cough, and sore throat. Duration of myalgia may be related to the severity of COVID-19 disease. Few patients had muscle weakness and elevated creatine kinase along with elevated levels of acute-phase reactants. All these patients with myositis/rhabdomyolysis had severe respiratory complications related to COVID-19. A handful of patients with myasthenia gravis showed exacerbation of their disease after acquiring COVID-19 disease. Most of these patients recovered with either intravenous immunoglobulins or steroids.