Clinical neurophysiology and cerebrospinal liquor analysis to detect Guillain-Barré syndrome and polyneuritis cranialis in COVID-19 patients: A case series

Long-term effects of SARS-CoV-2 infection in patients with and without chemosensory disorders at disease onset: a psychophysical and magnetic resonance imaging exploratory study

A preserved sense of smell and taste allows us to understand many environmental "messages" and results in meaningfully improvements to quality of life. With the COVID-19 pandemic, it became clear how important these senses are for social and nutritional status and catapulted this niche chemosensory research area towards widespread interest. In the current exploratory work, we assessed two groups of post-COVID-19 patients who reported having had (Group 1) or not (Group 2) a smell/taste impairment at the disease onset. The aim was to compare them using validated smell and taste tests as well as with brain magnetic resonance imaging volumetric analysis. Normative data were used for smell scores comparison and a pool of healthy subjects, recruited before the pandemic, served as controls for taste scores. The majority of patients in both groups showed an olfactory impairment, which was more severe in Group 1 (median UPSIT scores: 24.5 Group 1 vs 31.0 Group 2, p = 0.008), particularly among women (p = 0.014). No significant differences emerged comparing taste scores between Group 1 and Group 2, but dysgeusia was only present in Group 1 patients. However, for taste scores, a significant difference was found between Group 1 and controls (p = 0.005). No MRI anatomical abnormalities emerged in any patients while brain volumetric analysis suggested a significant difference among groups for the right caudate nucleus (p = 0.028), although this was not retained following Benjamini-Hochberg correction. This exploratory study could add new information in COVID-19 chemosensory long-lasting impairment and address future investigations on the post-COVID-19 patients' research.

Post-COVID-19 patients suffer from chemosensory, trigeminal, and salivary dysfunctions

Recent literature indicates that post-COVID-19 patients suffer from a plethora of complications, including chemosensory dysfunction. However, little attention has been given to understand the interactions between chemosensory, trigeminal, and salivary dysfunctions in these patients. The aims of this study were (1) to investigate the prevalence and combinations of chemosensory, trigeminal, and salivary dysfunctions, (2) to identify the odorants/tastants that are compromised, and (3) to explore possible associations between the four dysfunctions in post-COVID-19 patients. One hundred post-COVID-19 patients and 76 healthy controls (pre-COVID-19) were included in this cross-sectional, case-controlled study. Participants' smell, taste, trigeminal, and salivary functions were assessed. The patients had a significantly higher prevalence of parosmia (80.0%), hyposmia (42.0%), anosmia (53.0%), dysgeusia (34.0%), complete ageusia (3.0%), specific ageusia (27.0%), dysesthesia (11.0%) and dry mouth (18.0%) compared to controls (0.0% for all parameters, except 27.6% for hyposmia). Complete loss of bitter taste was the most prevalent specific ageusia (66.7%) and coffee was the most common distorted smell (56.4%). Seven different combinations of dysfunction were observed in the patients, the most common being a combination of olfactory and gustatory dysfunction (48.0%). These findings indicate that post-COVID-19 patients experience a range of chemosensory, trigeminal, and salivary disturbances, occurring in various combinations.

Persisting Shadows: Unraveling the Impact of Long COVID-19 on Respiratory, Cardiovascular, and Nervous Systems

The coronavirus disease 2019 (COVID-19), instigated by the zoonotic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), rapidly transformed from an outbreak in Wuhan, China, into a widespread global pandemic. A significant post-infection condition, known as 'long- COVID-19' (or simply 'long- COVID'), emerges in a substantial subset of patients, manifesting with a constellation of over 200 reported symptoms that span multiple organ systems. This condition, also known as 'post-acute sequelae of SARS-CoV-2 infection' (PASC), presents a perplexing clinical picture with far-reaching implications, often persisting long after the acute phase. While initial research focused on the immediate pulmonary impact of the virus, the recognition of COVID-19 as a multiorgan disruptor has unveiled a gamut of protracted and severe health issues. This review summarizes the primary effects of long COVID on the respiratory, cardiovascular, and nervous systems. It also delves into the mechanisms underlying these impacts and underscores the critical need for a comprehensive understanding of long COVID's pathogenesis.

What Is the Impact of the Novel Coronavirus and the Vaccination on Guillain-Barre Syndrome?

The COVID-19 pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has resulted in devastating medical and economic consequences worldwide over the past 3 years. As the pandemic enters a new stage, it is essential to consider the potential impact on rare diseases such as Guillain-Barre syndrome (GBS), which has been intimately associated with COVID-19 since the first COVID-19-related GBS case was reported in January 2020. There are notable differences between COVID-19-related GBS and GBS without COVID-19 in terms of diagnostic types and clinical manifestations. Furthermore, with the widespread administration of COVID-19 vaccines, there have been reports of GBS occurring shortly after vaccination, which requires close attention despite its rarity. This review also explores the vaccines associated with heightened GBS risks, offering insights that may guide vaccination policies and clinical practice. To provide a visual summary of these findings, we have included a graphical abstract. This article will discuss the characteristic manifestations of GBS patients after being positive for the novel coronavirus and the safety of several COVID-19 vaccines. Firstly, this article comprehensively expounds and discusses the epidemiological aspects of novel coronavirus-related GBS. For example, from the perspective of the same population, the expected incidence of GBS in the COVID-19-positive population (persons/100,000 persons/ year) is about 43 times that of the COVID-19-negative population, and the incidence of GBS is significantly increased. Secondly, the clinical characteristics of COVID-19-negative GBS patients and SARS-CoV-2-GBS (SC2-GBS) patients were summarized and compared. Thirdly, this article reviews GBS cases in the current adverse events after COVID-19 vaccination and analyzes and discusses from multiple perspectives, such as the incidence of GBS events, the age proportion of patients, and the interval of onset.

Neurological manifestations of COVID-19: a systematic review and detailed comprehension

The current pandemic caused by severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is accompanied with a rapid increase of reports and papers detailing its neurological effects and symptoms. The virus infection causes respiratory illness named by the world health organization as corona virus 19 (COVID-19).This systematic review aims to study and summarize the different neurological manifestations of this virus. All articles published and indexed via Pubmed, Medline and Google Scholar databases between January 1st 2020 and February 28th 2021 that reported neurological symptoms of SARS-CoV-2 are reviewed following the Preferred Reporting Items for Systemic review and Meta-Analysis (PRISMA) guidelines.We included data from 113 articles: eight prospective studies, 25 retrospective studies and the rest were case reports/series. COVID-19 can present with central nervous system manifestations, such as headache, encephalitis and encephalopathy, peripheral nervous system manifestations, such as anosmia, ageusia and Guillian Barre syndrome, and skeletal muscle manifestations, such as myalgia and myasthenia gravis. Our systematic review showed that COVID-19 can be manifested by a wide spectrum of neurological symptoms reported either in the early stage or within the course of the disease. However, a detailed comprehension of these manifestations is required and more studies are needed in order to improve our scientific knowledge and to develop preventive and therapeutic measures to control this pandemic.

Deficient GABABergic and glutamatergic excitability in the motor cortex of patients with long-COVID and cognitive impairment

OBJECTIVE

Attention, working memory and executive processing have been reported to be consistently impaired in Neuro-Long coronavirus disease (COVID). On the hypothesis of abnormal cortical excitability, we investigated the functional state of inhibitory and excitatory cortical regulatory circuits by single "paired-pulse" transcranial magnetic stimulation (ppTMS) and Short-latency Afferent Inhibition (SAI).

METHODS

We compared clinical and neurophysiological data of 18 Long COVID patients complaining of persistent cognitive impairment with 16 Healthy control (HC) subjects. Cognitive status was evaluated by means of the Montreal Cognitive Assessment (MoCA) and a neuropsychological evaluation of the executive function domain; fatigue was scored by the Fatigue Severity Scale (FSS). Resting motor threshold (RMT), the amplitude of the motor evoked potential (MEP), Short Intra-cortical Inhibition (SICI), Intra-cortical Facilitation (ICF), Long-interval Intracortical Inhibition (LICI) and Short-afferent inhibition (SAI) were investigated over the motor (M1) cortex.

RESULTS

MoCA corrected scores were significantly different between the two groups (p = 0.023). The majority of the patients' performed sub-optimally in the neuropsychological assessment of the executive functions. The majority (77.80%) of the patients reported high levels of perceived fatigue in the FSS. RMT, MEPs, SICI and SAI were not significantly different between the two groups. On the other hand, Long COVID patients showed a reduced amount of inhibition in LICI (p = 0.003) and a significant reduction in ICF (p < 0.001).

CONCLUSIONS

Neuro-Long COVID patients performing sub-optimally in the executive functions showed a reduction of LICI related to GABAb inhibition and a reduction of ICF related to glutamatergic regulation. No alteration in cholinergic circuits was found.

SIGNIFICANCE

These findings can help to better understand the neurophysiological characteristics of Neuro-Long COVID, and in particular, motor cortex regulation in people with "brain fog".

A likely association between low mannan-binding lectin level and brain fog onset in long COVID patients

Brain fog can be described as a constellation of new-onset neuropsychiatric sequelae in the post-acute phase of COVID-19 (long COVID). The symptoms include inattention, short-term memory loss, and reduced mental acuity, which may undermine cognition, concentration, and sleep. This cognitive impairment, persisting for weeks or months after the acute phase of SARS-CoV-2 infection, can significantly impact on daily activities and the quality of life. An important role for the complement system (C) in the pathogenesis of COVID-19 has emerged since the beginning of pandemic outbreak. A number of pathophysiological characteristics including microangiopathy and myocarditis have been attributed to dysregulated C activation due to SARS-CoV-2 infection. Mannan-binding lectin (MBL), the first recognition subcomponent of the C lectin pathway, has been shown to bind to glycosylated SARS-CoV-2 spike protein, genetic variants of MBL2 are suggested to have an association with severe COVID-19 manifestations requiring hospitalization. In the present study, we evaluated MBL activity (lectin pathway activation) and levels in the sera of a cohort of COVID-19 patients, presenting brain fog or only hyposmia/hypogeusia as persistent symptoms, and compared them with healthy volunteers. We found significantly lower levels of MBL and lectin pathway activity in the sera of patients experiencing brain fog as compared to recovered COVID-19 patients without brain fog. Our data indicate that long COVID-associated brain fog can be listed among the variegate manifestations of increased susceptibility to infections and diseases contributed by MBL deficiency.

Efficacy of intravenous immunoglobulin (IVIg) on COVID-19-related neurological disorders over the last 2 years: an up-to-date narrative review

Introduction

Among the clinical manifestations of SARS-CoV-2 infection, neurological features have been commonly reported and the state-of-the-art technique suggests several mechanisms of action providing a pathophysiological rationale for central and peripheral neurological system involvement. However, during the 1st months of the pandemic, clinicians were challenged to find the best therapeutic options to treat COVID-19-related neurological conditions.

Methods

We explored the indexed medical literature in order to answer the question of whether IVIg could be included as a valid weapon in the therapeutic arsenal against COVID-19-induced neurological disorders.

Results

Virtually, all reviewed studies were in agreement of detecting an acceptable to great efficacy upon IVIg employment in neurological diseases, with no or mild adverse effects. In the first part of this narrative review, the interaction of SARS-CoV-2 with the nervous system has been discussed and the IVIg mechanisms of action were reviewed. In the second part, we collected scientific literature data over the last 2 years to discuss the use of IVIg therapy in different neuro-COVID conditions, thus providing a summary of the treatment strategies and key findings.

Discussion

Intravenous immunoglobulin (IVIg) therapy is a versatile tool with multiple molecular targets and mechanisms of action that might respond to some of the suggested effects of infection through inflammatory and autoimmune responses. As such, IVIg therapy has been used in several COVID-19-related neurological diseases, including polyneuropathies, encephalitis, and status epilepticus, and results have often shown improvement of symptoms, thus suggesting IVIg treatment to be safe and effective.

Guillain-Barré syndrome AMSAN variant in a 90-year-old woman after COVID-19: a case report

BACKGROUND

Guillain-Barré syndrome (GBS) is an inflammatory disease of the peripheral nervous system characterized by rapidly evolving polyneuropathy caused by autoimmune demyelination and/or axonal degeneration. Since SARS-CoV-2 outbreak, several GBS cases following exposure to coronavirus disease-2019 (COVID-19) have been reported in literature, raising the concern of the latter being a potential trigger event for GBS.

CASE PRESENTATION

We report the case of a 90-year-old Caucasian woman who was admitted to our hospital because of fatigue, worsening gait and leg strength, dysphonia, dysarthria and dysphagia, started 3 weeks after being exposed to COVID-19. Based on clinical presentation GBS was suspected, so she performed a lumbar puncture and electromyography, which confirmed the diagnosis of acute motor and sensory axonal neuropathy (AMSAN) variant. We administered high dose of intravenous immunoglobulin with slight neurological improvement. However, after 2 weeks of hospitalization with maximization of care, her physical condition worsen, manifesting severe frailty. The patient was discharged with home support services for managing parenteral nutrition and intense scheduled physiotherapy. A few days later, the patient experienced a further decline in her clinical condition and died at home.

CONCLUSIONS

To the best of our knowledge, we report the oldest woman with GBS AMSAN variant after COVID-19 described in the existing literature. Our case supports further research aimed at improving recognition, characterization and prompt management of neurological diseases related to COVID-19 in older patients.

Cognitive deficit in post-acute COVID-19: an opportunity for EEG evaluation?

BACKGROUND AND PURPOSE

Among the most common post-COVID symptoms, many patients experienced subjective cognitive deficit, commonly named "brain fog," that might be present also in those individuals without severe acute COVID-19 respiratory involvement. Some studies have investigated some of the mechanisms that might be associated with the brain fog with objective techniques including transcranial magnetic stimulation and neuroimaging.

METHODS

The aim of this study was to investigate the presence of electroencephalographic (EEG) alterations in people with post-COVID self-reported cognitive deficit.

RESULTS

Out of the 90 patients attending the post-COVID neurology ambulatory service, twenty patients presenting brain fog at least 4 weeks after acute non-severe COVID-19 infection, and without previous history of epilepsy, were investigated with 19-channel EEG, Montreal Cognitive Assessment (MoCA), and magnetic resonance imaging (MRI). EEG was found altered in 65% of the sample, among which 69% presented a slowing activity and 31% were characterized by epileptic discharges principally in the frontal areas. None of the patients showed DWI MRI lesions.

CONCLUSIONS

These findings highlight the usefulness of EEG analysis to objectively describe possible neurophysiological abnormalities in post-COVID patients presenting subjective cognitive deficit.

Cranial Nerve Impairment Associated With COVID-19 Infections: A Systematic Review

The COVID-19 pandemic has created huge economic and healthcare burdens. In most cases, the virus affects the lungs and causes respiratory symptoms. Additionally, its impact on the cranial nerves remains unclear. We thus aimed to investigate cranial nerve dysfunction in patients with COVID-19 infection.  We conducted a systematic literature search of relevant and eligible literature in five databases: PubMed, Web of Science, Medline, EBSCO, and Google Scholar.  Our sample included 21 case reports, one case series with 29 patients, and one analytical study with 135 cases. Participant ages ranged from 23 months to 72 years (mean age of 47.5 ± 19.02). The mean time from respiratory symptoms to the onset of neurological signs was (9.6 ± 7.4) days, and the mean recovery time was (16.3 ± 15.3) days.  Cranial nerve impairment associated with COVID-19 infection has affected a large population, from infants to the elderly. Facial and abducent nerves were the most commonly affected cranial nerves with reported good prognosis or complete recovery within a few days to weeks. Olfactory dysfunctions were widely detected among COVID-19 patients.

Facial palsy as a manifestation of COVID-19: A systematic review of cases

Background and Aims

Facial palsy is a rare complication of the COVID-19 infection. Herein, we conducted a systematic review of all published cases of facial palsy post-COVID-19 infection in an attempt to educate the general population and medical practitioners regarding the likely occurrence of facial palsy in COVID-19 patients, its detection, effective treatment plan, and prognosis of the condition.

Methods

We searched PubMed, Google Scholar, and Directory of Open Access Journals (DOAJ) from December 1, 2019 to September 21, 2021.

Results

We included 49 studies bearing accounts of 75 cases who had facial palsy. The mean age of patients was 42.9 ± 19.59 years, with a male-to-female ratio of 8:7. The majority of the cases were reported from Brazil (n = 14), USA (n = 9), Turkey (n = 9), and Spain (n = 9). Noticeably, 30.14% of COVID-19 patients were diagnosed with Guillain-Barré syndrome. In total, 22.97% of patients complained of bilateral facial paralysis (n = 17), whereas ipsilateral paralysis was observed in 77.03% (n = 57). These were common complaints of Lagophthalmos, otalgia, facial drooping, dysarthria, and compromised forehead wrinkling. The treatment regimen mainly included the use of corticosteroids (n = 51) (69.86%), antivirals (n = 23) (31.51%), IVIG (n = 18) (24.66%), antibiotics (n = 13) (17.81%), antiretroviral (n = 9) (12.33%), and antimalarial (n = 8) (10.96%) medications. In all, 35.62% of patients (n = 26) adhered to a combination of antiviral and corticosteroid-based therapy. Positive treatment outcomes were observed in 83.58% (n = 56) of cases. In contrast, 10 patients (14.93%) showed nonsignificant recovery, out of which 3 (4.48%) died from the disease.

Conclusion

The association of facial palsy with COVID-19 is controversial and therefore requires further investigation and published work to confirm a causal relationship. However, physicians should not overlook the likelihood of facial palsy post-COVID-19 infection and treat it accordingly.

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.

Electrophysiological evidence of subclinical trigeminal dysfunction in patients with COVID-19 and smell impairment: A pilot study

Background

Smell and taste disturbances are among the most frequent neurological symptoms in patients with COVID-19. A concomitant impairment of the trigeminal nerve has been suggested in subjects with olfactory dysfunction, although it has not been confirmed with objective measurement techniques. In this study, we explored the trigeminal function and its correlations with clinical features in COVID-19 patients with impaired smell perception using electrophysiological testing.

Methods

We enrolled 16 consecutive patients with mild COVID-19 and smell impairment and 14 healthy controls (HCs). Olfactory and gustatory symptoms were assessed with self-reported questionnaires. Electrophysiological evaluation of the masseter inhibitory reflex (MIR) and blink reflex (BR) was carried out to test the trigeminal function and its connections within the brainstem.

Results

Masseter inhibitory reflex (MIR) analysis revealed higher latency of ipsilateral and contralateral early silent period in patients when compared with HCs. No significant differences between groups were detected as regards the duration of the early and late silent period. However, several patients showed a prolonged duration of the early silent period. BR evaluation disclosed only an increased amplitude of early components in patients.

Conclusions

Patients with COVID-19 and smell impairment show a subclinical trigeminal nerve impairment. Trigeminal alterations mainly involve the oligosynaptic pathway, as a result of either direct viral damage or secondary neuroinflammation of the peripheral trigeminal fibers, whereas the polysynaptic ponto-medullary circuits seem to be spared. The prolonged duration of the early silent period and the increased amplitude of early BR response might reflect a compensatory upregulation of the trigeminal function as a consequence of the olfactory dysfunction.

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

COVID-19 disease and autoimmune disorders: A mutual pathway

Coronavirus disease 2019 (COVID-19) is a real challenge for humanity with high morbidity and mortality. Despite being primarily a respiratory illness, COVID-19 can affect nearly every human body tissue, causing many diseases. After viral infection, the immune system can recognize the viral antigens presented by the immune cells. This immune response is usually controlled and terminated once the infection is aborted. Nevertheless, in some patients, the immune reaction becomes out of control with the development of autoimmune diseases. Several human tissue antigens showed a strong response with antibodies directed against many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins, such as SARS-CoV-2 S, N, and autoimmune target proteins. The immunogenic effects of SARS-CoV-2 are due to the sizeable viral RNA molecules with interrupted transcription increasing the pool of epitopes with increased chances of molecular mimicry and interaction with the host immune system, the overlap between some viral and human peptides, the viral induced-tissue damage, and the robust and complex binding between sACE-2 and SARS-CoV-2 S protein. Consequently, COVID-19 and its vaccine may trigger the development of many autoimmune diseases in a predisposed patient. This review discusses the mutual relation between COVID-19 and autoimmune diseases, their interactive effects on each other, the role of the COVID-19 vaccine in triggering autoimmune diseases, the factors affecting the severity of COVID-19 in patients suffering from autoimmune diseases, and the different ways to minimize the risk of COVID-19 in patients with autoimmune diseases.

Guillain-Barré Syndrome and COVID-19: a one-year observational multicenter study

Background and purpose

Many single cases and small series of Guillain–Barré syndrome (GBS) associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection were reported during the coronavirus disease 19 (COVID‐19) outbreak worldwide. However, the debate regarding the possible role of infection in causing GBS is still ongoing. This multicenter study aimed to evaluate epidemiological and clinical findings of GBS diagnosed during the COVID‐19 pandemic in northeastern Italy in order to further investigate the possible association between GBS and COVID‐19.

Methods

Guillain–Barré syndrome cases diagnosed in 14 referral hospitals from northern Italy between March 2020 and March 2021 were collected and divided into COVID‐19‐positive and COVID‐19‐negative. As a control population, GBS patients diagnosed in the same hospitals from January 2019 to February 2020 were considered.

Results

The estimated incidence of GBS in 2020 was 1.41 cases per 100,000 persons/year (95% confidence interval 1.18–1.68) versus 0.89 cases per 100,000 persons/year (95% confidence interval 0.71–1.11) in 2019. The cumulative incidence of GBS increased by 59% in the period March 2020–March 2021 and, most importantly, COVID‐19‐positive GBS patients represented about 50% of the total GBS cases with most of them occurring during the two first pandemic waves in spring and autumn 2020. COVID‐19‐negative GBS cases from March 2020 to March 2021 declined by 22% compared to February 2019–February 2020.

Conclusions

Other than showing an increase of GBS in northern Italy in the “COVID‐19 era” compared to the previous year, this study emphasizes how GBS cases related to COVID‐19 represent a significant part of the total, thus suggesting a relation between COVID‐19 and GBS.

A Systematic Review on Neurological Aspects of COVID-19: Exploring the Relationship Between COVID-19-Related Olfactory Dysfunction and Neuroinvasion

Objectives

To identify neurological aspects of Coronavirus disease 2019 (COVID-19) and to investigate COVID-19 infected patients with and without olfactory dysfunction in relation to polymerase chain reaction (PCR) assay results for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in the cerebrospinal fluid (CSF).

Methods

PubMed and EMBASE databases were searched until March 26, 2021, for observational studies with COVID-19 patients that had performed CSF PCR assay due to the neurologic symptom and reported anosmia status.

Results

Initially, 2,387 studies were identified;167 studies performed SARS-CoV-2 CSF PCR assay, of which our review comprised 45 observational studies that conducted CSF PCR assay for SARS-CoV-2 in 101 patients and reported anosmia status in 55 of 101 patients. Central and peripheral neurological manifestations observed in COVID-19 patients were diverse. The most common neurological diagnoses were Guillain-Barré syndrome (GBS) and its variants (24%), followed by encephalopathy (21%). The SARS-CoV-2 PCR assay was positive in only four CSF samples, of which two patients had olfactory dysfunction while the others did not.

Conclusions

The neurological spectrum of COVID-19 is diverse, and direct neuroinvasion of SARS-CoV-2 is rare. The neuroprotection against SARS-CoV-2 in COVID-19 patients with anosmia is controversial, as an equal number of patients with and without olfactory dysfunction had positive CSF PCR results for SARS-CoV-2 in our study, and further studies are required to provide more insight into this topic.

Sex-dependent characteristics of Neuro-Long-COVID: Data from a dedicated neurology ambulatory service

“Long-COVID” is a clinical entity that consists of persisting post-infectious symptoms that last for more than three months after the onset of the first acute COVID-19 symptoms. Among these, a cluster of neurological persisting symptoms defines Neuro-Long-COVID. While the debate about the pathogenesis of Long-COVID is still ongoing, sex differences have been individuated for both the acute and the chronic stage of the infection. We conducted a retrospective study describing sex differences in a large sample of patients with Neuro-Long-COVID. Demographic and clinical data were collected in a specifically designed Neuro-Long-Covid outpatient service. Our sample included 213 patients: 151 were females and 62 were males; the mean age was similar between females (53 y, standard deviation 14) and males (55 y, standard deviation 15); no significant differences was present between the demographic features across the two groups. Despite the prevalence of the specific chronic symptoms between male and females showed no significant differences, the total number of females accessing our service was higher than that of males, confirming the higher prevalence of Neuro-Long-COVID in female individuals. Conversely, a worse acute phase response in males rather than females was confirmed by a significant difference in the rates of acute respiratory symptoms (p = 0.008), dyspnea (p = 0.018), respiratory failure (p = 0.010) and the consequent need for ventilation (p = 0.015), together with other acute symptoms such as palpitations (p = 0.049), headache (p = 0.001) and joint pain (p = 0.049). Taken together, these findings offer a subgroup analysis based on sex-dependent characteristics, which can support a tailored-medicine approach.

SARS-CoV-2 and Guillain-Barré Syndrome: Lessons from Viral Infections

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. COVID-19 has a broad clinical spectrum from asymptomatic patients to multiorgan dysfunction and septic shock. Most of the common symptoms of COVID-19 are classified as respiratory disorders, but some reports show neurological involvements. During the COVID-19 pandemic, a case series of neurological complications, such as Guillain-Barré syndrome (GBS), were reported. GBS is a neuroimmune disorder with acute inflammatory radicular polyneuropathy in different parts of the peripheral nerve. Some studies have reported GBS as an inflammatory neuropathy related to various viral infections, such as cytomegalovirus (CMV), Epstein-Barr Virus (EBV), herpes simplex virus (HSV), human immunodeficiency virus (HIV), influenza, and Zika virus. There are some immunomodulation approaches for the management of GBS. Studies have evaluated the effects of the various therapeutic approaches, including intravenous immunoglobulin (IVIG), plasma exchange (PE), complement inhibitors, and corticosteroids to regulate overactivation of immune responses during GBS in experimental and clinical studies. In this regard, the possible association between GBS and SARS-CoV-2 infection during the outbreak of the current pandemic and also the mentioned therapeutic approaches were reviewed.

Neurological and Head/Eyes/Ears/Nose/Throat Manifestations of COVID-19: A Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVE

Coronavirus disease 2019 (COVID-19) has been associated with various neurological and atypical head/eyes/ears/nose/throat (HEENT) manifestations. We sought to review the evidence for these manifestations.

METHODS

In this systematic review and meta-analysis, we compiled studies published until March 31, 2021 that examined non-respiratory HEENT, central, and peripheral nervous system presentations in COVID-19 patients. We included 477 studies for qualitative synthesis and 59 studies for meta-analyses.

RESULTS

Anosmia, ageusia, and conjunctivitis may precede typical upper/lower respiratory symptoms. Central nervous system (CNS) manifestations include stroke and encephalopathy, potentially with brainstem or cranial nerve involvement. MRI studies support CNS para-/postinfectious etiologies, but direct neuroinvasion seems very rare, with few cases detecting Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the CNS. Peripheral nervous system (PNS) manifestations include muscle damage, Guillain-Barre syndrome (GBS), and its variants. There was moderate-to-high study heterogeneity and risk of bias. In random-effects meta-analyses, anosmia/ageusia was estimated to occur in 56% of COVID-19 patients (95% CI: 0.41-0.71, I2:99.9%), more commonly than in patients without COVID-19 (OR: 14.28, 95% CI: 8.39-24.29, I2: 49.0%). Neurological symptoms were estimated to occur in 36% of hospitalized patients (95% CI: 0.31-0.42, I2: 99.8%); ischemic stroke in 3% (95% CI: 0.03-0.04, I2: 99.2%), and GBS in 0.04% (0.033%-0.047%), more commonly than in patients without COVID-19 (OR[stroke]: 2.53, 95% CI: 1.16-5.50, I2: 76.4%; OR[GBS]: 3.43,1.15-10.25, I2: 89.1%).

CONCLUSIONS

Current evidence is mostly from retrospective cohorts or series, largely in hospitalized or critically ill patients, not representative of typical community-dwelling patients. There remains a paucity of systematically gathered prospective data on neurological manifestations. Nevertheless, these findings support a high index of suspicion to identify HEENT/neurological presentations in patients with known COVID-19, and to test for COVID-19 in patients with such presentations at risk of infection.

Neuroimmune disorders in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the aetiologic agent of the coronavirus disease 2019 (COVID-19), is now rapidly disseminating throughout the world with 147,443,848 cases reported so far. Around 30-80% of cases (depending on COVID-19 severity) are reported to have neurological manifestations including anosmia, stroke, and encephalopathy. In addition, some patients have recognised autoimmune neurological disorders, including both central (limbic and brainstem encephalitis, acute disseminated encephalomyelitis [ADEM], and myelitis) and peripheral diseases (Guillain-Barré and Miller Fisher syndrome). We systematically describe data from 133 reported series on the Neurology and Neuropsychiatry of COVID-19 blog ( https://blogs.bmj.com/jnnp/2020/05/01/the-neurology-and-neuropsychiatry-of-covid-19/ ) providing a comprehensive overview concerning the diagnosis, and treatment of patients with neurological immune-mediated complications of SARS-CoV-2. In most cases the latency to neurological disorder was highly variable and the immunological or other mechanisms involved were unclear. Despite specific neuronal or ganglioside antibodies only being identified in 10, many had apparent responses to immunotherapies. Although the proportion of patients experiencing immune-mediated neurological disorders is small, the total number is likely to be underestimated. The early recognition and improvement seen with use of immunomodulatory treatment, even in those without identified autoantibodies, makes delayed or missed diagnoses risk the potential for long-term disability, including the emerging challenge of post-acute COVID-19 sequelae (PACS). Finally, potential issues regarding the use of immunotherapies in patients with pre-existent neuro-immunological disorders are also discussed.

Acute neuromuscular syndromes with respiratory failure during COVID-19 pandemic: where we stand and challenges ahead

Coronavirus disease 2019 (COVID-19), a disease caused by the novel betacoronavirus SARS-COV-2, has become a global pandemic threat. SARS- COV-2 is structurally similar to SARS-COV, and both bind to the angiotensin-converting enzyme 2 (ACE2) receptor to enter human cells. While patients typically present with fever, shortness of breath, sore throat, and cough, in some cases neurologic manifestations occur due to both direct and indirect involvement of the nervous system. Case reports include anosmia, ageusia, central respiratory failure, stroke, acute necrotizing hemorrhagic encephalopathy, toxic-metabolic encephalopathy, headache, myalgia, myelitis, ataxia, and various neuropsychiatric manifestations. Some patients with COVID-19 may present with concurrent acute neuromuscular syndromes such as myasthenic crisis (MC), Guillain–Barré syndrome (GBS) and idiopathic inflammatory myopathies (IIM); these conditions coupled with respiratory failure could trigger a life-threatening condition. Here, we review the current state of knowledge on acute neuromuscular syndromes with respiratory failure related to COVID-19 infection in an attempt to clarify and to manage the muscle dysfunction overlapping SARS-COV-2 infection.

The potential association between COVID-19 disease and Guillain-Barré syndrome

The aim is to investigate the rate of GBS in the pre- and postpandemic period and potential differences in probable COVID-19-associated Guillain-Barré syndrome (GBS) cases and nonassociated cases. The medical records of individuals older than 18 years who were hospitalized with acute and rapidly developing progressive extremity weakness between March 2019 and March 2021 were analyzed retrospectively, and the rate of GBS 1 year before the first reported COVID-19 case (March 2020) in Turkey and 1 year later was compared. Neurological symptoms, medical histories, and GBS disability scores, as well as the findings of electrophysiological, blood, and cerebrospinal fluid (CSF) investigations at the time of presentation, were reviewed. The GBS cases were divided into those with confirmed COVID-19 within 6 weeks before the clinical presentation of GBS and those without COVID-19. The rate of COVID-19 was significantly higher in the patients with GBS as an etiological factor. When the probable COVID-19-associated GBS cases and nonassociated cases were compared, there was a significant between-group difference with respect to sedimentation, C-reactive protein, D-dimer, ferritin, albumin, lymphocyte number, mean platelet volume, neutrophil-lymphocyte ratio, fibrinogen, and lactate dehydrogenase values. In addition, there was a significant between-group difference in admission and discharge disability scores. The GBS rate did not increase after the COVID-19 pandemic, but probable COVID-19-associated GBS significantly affected inflammatory markers and admission-discharge GBS disability scores.

COVID-19 and the Peripheral Nervous System. A 2-year review from the pandemic to the vaccine era

Increasing literature has linked COVID‐19 to peripheral nervous system (PNS) diseases. In addition, as we move from the pandemic to the vaccination era, literature interest is shifting towards the potential association between COVID‐19 vaccines and PNS manifestations. We reviewed published literature on COVID‐19, COVID‐19 vaccines and PNS manifestations between 1 January 2020 and 1 December 2021. For Guillain‐Barré syndrome (GBS), isolated cranial neuropathy (ICN) and myositis associated with COVID‐19, the demographic, clinical, laboratory, electrophysiological and imaging features were included in a narrative synthesis. We identified 169 studies on COVID‐19‐associated complications, including 63 papers (92 patients) on GBS, 29 papers (37 patients) on ICN and 11 papers (18 patients) on myositis. Additional clinical phenotypes included chronic inflammatory demyelinating polyneuropathy, vasculitic neuropathies, neuralgic amyotrophy, critical care‐related complications, and myasthenia gravis. PNS complications secondary to COVID‐19 vaccines have been reported during randomized clinical trials, in real‐world case reports, and during large‐scale surveillance programs. These mainly include cases of GBS, Bell's palsy, and cases of neuralgic amyotrophy. Based on our extensive review of the literature, any conclusion about a pathophysiological correlation between COVID‐19 and PNS disorders remains premature, and solely supported by their temporal association, while epidemiological and pathological data are insufficient. The occurrence of PNS complications after COVID‐19 vaccines seems limited to a possible higher risk of facial nerve palsy and GBS, to a degree that widespread access to the ongoing vaccination campaign should not be discouraged, while awaiting for more definitive data from large‐scale surveillance studies.

Occupational and Physical Therapy Strategies for the Rehabilitation of COVID-19 Related Guillain-Barré Syndrome in the Long-Term Acute Care Hospital Setting: A Case Report

BACKGROUND

While several reports have described the diagnosis and treatment of patients with COVID-19 associated Guillain-Barré Syndrome (GBS), there is a paucity of literature describing the occupational and physical therapy strategies used in the long-term acute care hospital (LTACH) setting to rehabilitate these patients.

OBJECTIVE

A 61 year-old male was admitted to an LTACH for the rehabilitation of GBS following COVID-19 infection and intravenous immunoglobulin treatment.

METHODS

Rehabilitation in the LTACH setting uses a variety of skilled treatment interventions to meet patient driven goals and maximize their function to the highest level possible in preparation of their discharge to a subacute or homecare setting. In this case, this was accomplished through individual occupational and physical therapy sessions, occupational and physical therapy co-treatment sessions, and targeted group therapy sessions focused on leg, arm, and fine motor coordination exercises.

RESULTS

With the occupational and physical therapy standard of care, the patient's improvement was demonstrated by several outcome measures including manual muscle testing, range-of-motion, grip-strength, and the Activity Measure for Post-Acute Care. The patient was successfully rehabilitated and returned to the community after presenting with COVID-19 associated GBS.

CONCLUSIONS

This report highlights the complex rehabilitation needs patients require to regain independence after diagnosis of COVID-19 associated GBS.

Guillain Barre Syndrome as a Complication of COVID-19: A Systematic Review

BACKGROUND

In January 2020, the first case of Guillain Barre syndrome (GBS) due to COVID-19 was documented in China. GBS is known to be postinfectious following several types of infections. Although causality can only be proven through large epidemiological studies, we intended to study this association by a thorough review of the literature.

METHODS

We searched PubMed, EMBASE, and Google scholar and included all papers with English or Spanish full text and original data of patients with GBS and recent COVID infection. Variables of interest were demographics, diagnostic investigations, and the latency between arboviral and neurological symptoms. Further variables were pooled to identify GBS clinical and electrophysiological variants, used treatments, and outcomes. The certainty of GBS diagnosis was verified using Brighton criteria.

RESULTS

We identified a total of 109 GBS cases. Ninety-nine cases had confirmed COVID-19 infection with an average age of 56.07 years. The average latency period between the arboviral symptoms and neurologic manifestations for confirmed COVID-19 cases was 12.2 d. The predominant GBS clinical and electromyography variants were the classical sensorimotor GBS and acute demyelinating polyneuropathy respectively. Forty cases required intensive care, 33 cases required mechanical ventilation, and 6 cases were complicated by death.

CONCLUSIONS

Studies on COVID-19-related GBS commonly reported sensorimotor demyelinating GBS with frequent facial palsy. The time between the onset of infectious and neurological symptoms suggests a postinfectious mechanism. Early diagnosis of GBS in COVID-19 patients is important as it might be associated with a severe disease course requiring intensive care and mechanical ventilation.

Autoimmune complications of COVID-19

Coronavirus disease 2019 (COVID-19) is still propagating a year after the start of the pandemic. Besides the complications patients face during the COVID-19 disease period, there is an accumulating body of evidence concerning the late-onset complications of COVID-19, of which autoimmune manifestations have attracted remarkable attention from the first months of the pandemic. Autoimmune hemolytic anemia, immune thrombocytopenic purpura, autoimmune thyroid diseases, Kawasaki disease, Guillain-Barre syndrome, and the detection of autoantibodies are the cues to the discovery of the potential of COVID-19 in inducing autoimmunity. Clarification of the pathophysiology of COVID-19 injuries to the host, whether it is direct viral injury or autoimmunity, could help to develop appropriate treatment.

Guillain-Barré Syndrome in the COVID-19 Pandemic

There have been several reported cases of severe acute respiratory syndrome (SARS-CoV-2) infection that were associated with an increased incidence of neurological manifestations, including Guillain–Barré syndrome (GBS). This review aims to present information on the reports of GBS associated with coronavirus disease 2019 (COVID-19) infection. Our review is retrospective work examining articles published from the 1 April 2020 to the 8 May 2021 in the English language. We used the diagnostic criteria and classification published by the National Institute of Neurological Disorders and Stroke and Brighton Collaboration. GBS is usually a postinfectious syndrome, but GBS in the COVID-19 pandemic also takes on a para-infectious profile. In the reports, the genetic factor has a role in developing GBS in some patients. In conclusion, the association between COVID-19 and GBS is not very clear. Still, one mechanism is strongly associated with COVID-19 and immune-mediated neurological complications, which is molecular mimicry between SARS-CoV-2 and human autoantigens.

Global prevalence of persistent neuromuscular symptoms and the possible pathomechanisms in COVID-19 recovered individuals: A systematic review and meta-analysis

This study was conducted to determine the prevalence of prolonged neuromuscular symptoms, including fatigue, anosmia, headache, myalgia, and joint pain in COVID-19 survivors hospitalized with mild, moderate, or severe infections worldwide. The search was conducted up to January 30th, 2021 using three databases (PubMed, Scopus, and Web of Science) to identify potentially eligible studies. Data on study characteristics, follow-up characteristics, and severity of COVID-19 during hospitalization were collected in accordance with PRISMA guidelines. The Newcastle-Ottawa scale was used to assess the quality of relevant articles. The estimated prevalence of specific prolonged neuromuscular symptoms and the association between COVID-19 severity and occurrence of prolonged neuromuscular symptoms was analyzed wherever appropriate. Database search yielded 4,050 articles and 22 articles were included for meta-analysis. The estimated prevalence of prolonged fatigue was recorded in 21.2% (95%CI: 11.9%- 34.8%) of 3,730 COVID-19 survivors. Persistent anosmia was recorded in 239 of 2,600 COVID-19 survivors (9.7%, 95%CI: 6.1%-15.2%). In 84 out of 2,412 COVID-19 survivors (8.9%, 95%CI: 3.2%-22.6%), prolonged headache was observed. A total of 53 out of 1,125 COVID-19 patients (5.6%, 95%CI: 2.1%-14.2%) complained of persistent myalgia even after being discharged from the hospital. The prevalence of prolonged joint pain was in 15.4% (95%CI: 8.2%-27.2%) of subjects. Due to data scarcity on COVID-19 severity and prolonged neuromuscular symptoms, association analysis could not be conducted. Widespread concern regarding long-term impacts of COVID-19 was raised after several studies reported prolonged symptoms in COVID-19 survivors. Numerous theories have been proposed to address this concern; however, as the research on this pandemic is still ongoing, no explanation is definitive yet. Therefore, follow-up studies in COVID-19 survivors after recovery from COVID-19 are warranted to determine the pathogenesis of prolonged symptoms. PROSPERO registration: CRD42021242332.

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.

Infection of Human Cells by SARS-CoV-2 and Molecular Overview of Gastrointestinal, Neurological, and Hepatic Problems in COVID-19 Patients

The gastrointestinal tract is the body's largest interface between the host and the external environment. People infected with SARS-CoV-2 are at higher risk of microbiome alterations and severe diseases. Recent evidence has suggested that the pathophysiological and molecular mechanisms associated with gastrointestinal complicity in SARS-CoV-2 infection could be explained by the role of angiotensin-converting enzyme-2 (ACE2) cell receptors. These receptors are overexpressed in the gut lining, leading to a high intestinal permeability to foreign pathogens. It is believed that SARS-CoV-2 has a lesser likelihood of causing liver infection because of the diminished expression of ACE2 in liver cells. Interestingly, an interconnection between the lungs, brain, and gastrointestinal tract during severe COVID-19 has been mentioned. We hope that this review on the molecular mechanisms related to the gastrointestinal disorders as well as neurological and hepatic manifestations experienced by COVID-19 patients will help scientists to find a convenient solution for this and other pandemic events.

Relevance of CSF, Serum and Neuroimaging Markers in CNS and PNS Manifestation in COVID-19: A Systematic Review of Case Report and Case Series

BACKGROUND

The data on neurological manifestations in COVID-19 patients has been rapidly increasing throughout the pandemic. However, data on CNS and PNS inflammatory disorders in COVID-19 with respect to CSF, serum and neuroimaging markers is still lacking.

METHODS

We screened all articles resulting from a search of PubMed, Google Scholar and Scopus, using the keywords "SARS-CoV-2 and neurological complication", "SARS-CoV-2 and CNS Complication" and "SARS-CoV-2 and PNS Complication" looking for transverse myelitis, vasculitis, acute disseminated encephalomyelitis, acute hemorrhagic necrotizing encephalitis (AHNE), cytotoxic lesion of the corpus callosum (CLOCC) and Guillain-Barré syndrome (GBS), published between 1 December 2019 to 15 July 2021.

RESULTS

Of the included 106 CNS manifestations in our study, CNS inflammatory disorders included transverse myelitis (17, 14.7%), AHNE (12, 10.4%), ADEM (11, 9.5%), CLOCC/MERS (10, 8.6%) and vasculitis (4, 3.4%). Others were nonspecific encephalopathy, encephalitis, seizures and stroke. Most patients were >50 years old (75, 70.8%) and male (64, 65.3%). Most (59, 63.4%) were severe cases of COVID-19 and 18 (18%) patients died. Of the included 94 PNS manifestations in our study, GBS (89, 92.7%) was the most common. Most of these patients were >50 years old (73, 77.7%) and male (59, 64.1%). Most (62, 67.4%) were non-severe cases of COVID-19, and ten patients died.

CONCLUSION

Our comprehensive review of the clinical and paraclinical findings in CNS and PNS manifestations of COVID-19 provide insights on the pathophysiology of SARS-CoV-2 and its neurotropism. The higher frequency and severity of CNS manifestations should be noted by physicians for increased vigilance in particular COVID-19 cases.

Persistent chemosensory dysfunction in a young patient with mild COVID-19 with partial recovery 15 months after the onset

Objective

It is reported that recovery from COVID-19 chemosensory deficit generally occurs in a few weeks, although olfactory dysfunction may persist longer. Here, we provide a detailed follow-up clinical investigation in a very young female patient (17-year-old) with a long-lasting anosmia after a mild infection, with partial recovery 15 months after the onset.

Methods

Neuroimaging and neurophysiologic assessments as well as olfactory mucosa swabbing for microbiological and immunocytochemical analyses were performed. Olfactory and gustatory evaluations were conducted through validated tests.

Results

Chemosensory evaluations were consistent with anosmia associated with parosmia phenomena and gustatory impairment, the latter less persistent. Brain MRI (3.0 T) showed no microvascular injury in olfactory bulbs and brain albeit we cannot rule out slight structural abnormalities during the acute phase, and a high-density EEG was negative. Immunocytochemistry of olfactory mucosa swabs showed high expression of ACE2 in sustentacular cells and lower dot-like cytoplasmic positivity in neuronal-shaped cells.

Discussion

The occurrence of long-term persistent olfactory deficit in spite of the absence of structural brain and olfactory bulb involvement supports the view of a possible persistent dysfunction of both sustentacular cells and olfactory neurons. The gustatory dysfunction even if less persisting for the described features could be related to a primary gustatory system involvement. Future longitudinal studies are needed to investigate the persistence of chemosensory impairment, which could have a relevant impact on the daily life.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05635-y.

Treatment Options for COVID-19-Related Guillain-Barré Syndrome: A Systematic Review of Literature

BACKGROUND

Central nervous system complications are reported in an increasing number of patients with Coronavirus Disease 2019 (COVID-19). COVID-19-related Guillain-Barré syndrome (GBS) is of particular importance given its association with higher mortality rates and prolonged respiratory failure.

REVIEW SUMMARY

We conducted a systematic review of published cases for COVID-19-related GBS, and provide a summary of clinical management strategies for these cases. Sixty-three studies, including 86 patients, were included. Seventy-six cases with reported outcome data were eligible for the outcome analysis. Ninety-nine percent of patients were diagnosed with COVID-19 before diagnosis of GBS (median: 14 d prior, interquartile range: 7 to 20). Intravenous immunotherapy (intravenous immunoglobulin: 0.4 g/kg/d for 5 d) was the most frequently used treatment approach. The review indicated that the outcome was not favorable in 26% of cases (persistent neurological deficits). A mortality rate of 3.5% was observed in patients with COVID-19-related GBS.

CONCLUSIONS

Although evidence to support specific treatments is lacking, clinicians should consider the benefits of immunotherapy and plasma exchange in addition to the standard antimicrobial and supportive therapies for patients who meet the diagnostic criteria for acute sensory and motor polyradiculoneuritis. Intravenous immunoglobulin treatment alone is not shown to result in improved outcomes or mortality. More extensive studies aimed at exploring the neurological manifestations and complications of COVID-19 and distinctive treatment options for COVID-19-related GBS are warranted.

Neurologic Features Associated With SARS-CoV-2 Infection in Children: A Case Series Report

INTRODUCTION

Although multiple neurologic manifestations associated with SARS-CoV-2 infection have been described in adults, there is little information about those presented in children. Here, we described neurologic manifestations associated with COVID-19 in the pediatric population.

METHODS

Retrospective case series report. We included patients younger than 18 years, admitted with confirmed SARS-CoV-2 infection and neurologic manifestations at our hospital in Santiago, Chile. Demographics, clinical presentations, laboratory results, radiologic and neurophysiological studies, treatment, and outcome features were described. Cases were described based on whether they presented with predominantly central or peripheral neurologic involvement.

RESULTS

Thirteen of 90 (14.4%) patients admitted with confirmed infection presented with new-onset neurologic symptoms and 4 patients showed epilepsy exacerbation. Neurologic manifestations ranged from mild (headache, muscle weakness, anosmia, ageusia), to severe (status epilepticus, Guillain-Barré syndrome, encephalopathy, demyelinating events).

CONCLUSIONS

We found a wide range of neurologic manifestations in children with confirmed SARS-CoV-2 infection. In general, neurologic symptoms were resolved as the systemic presentation subsided. It is essential to recognize and report the main neurologic manifestations related to this new infectious disease in the pediatric population. More evidence is needed to establish the specific causality of nervous system involvement.

Autonomic dysfunction in post-COVID patients with and witfhout neurological symptoms: a prospective multidomain observational study

The autonomic nervous system (ANS) can be affected by COVID-19, and dysautonomia may be a possible complication in post-COVID individuals. Orthostatic hypotension (OH) and postural tachycardia syndrome (POTS) have been suggested to be common after SARS-CoV-2 infection, but other components of ANS function may be also impaired. The Composite Autonomic Symptom Scale 31 (COMPASS-31) questionnaire is a simple and validated tool to assess dysautonomic symptoms. The aim of the present study was to administer the COMPASS-31 questionnaire to a sample of post-COVID patients with and without neurological complaints. Participants were recruited among the post-COVID ambulatory services for follow-up evaluation between 4 weeks and 9 months from COVID-19 symptoms onset. Participants were asked to complete the COMPASS-31 questionnaire referring to the period after COVID-19 disease. Heart rate and blood pressure were manually taken during an active stand test for OH and POTS diagnosis. One-hundred and eighty participants were included in the analysis (70.6% females, 51 ± 13 years), and OH was found in 13.8% of the subjects. Median COMPASS-31 score was 17.6 (6.9-31.4), with the most affected domains being orthostatic intolerance, sudomotor, gastrointestinal and pupillomotor dysfunction. A higher COMPASS-31 score was found in those with neurological symptoms (p < 0.01), due to more severe orthostatic intolerance symptoms (p < 0.01), although gastrointestinal (p < 0.01), urinary (p < 0.01), and pupillomotor (p < 0.01) domains were more represented in the non-neurological symptoms group. This study confirms the importance of monitoring ANS symptoms as a possible complication of COVID-19 disease that may persist in the post-acute period.

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.

Peripheral nerve adaptations to 10 days of horizontal bed rest in healthy young adult males

Space analogs, such as bed rest, are used to reproduce microgravity-induced morphological and physiological changes and can be used as clinical models of prolonged inactivity. Nevertheless, nonuniform decreases in muscle mass and function have been frequently reported, and peripheral nerve adaptations have been poorly studied, although some of these mechanisms may be explained. Ten young healthy males (18-33 yr) underwent 10 days of horizontal bed rest. Peripheral neurophysiological assessments were performed bilaterally for the dominant (DL) and nondominant upper and lower limbs (N-DL) on the 1st and 10th day of bed rest, including ultrasound of the median, deep peroneal nerve (DPN), and common fibular nerve (CFN) , as well as a complete nerve conduction study (NCS) of the upper and lower limbs. Consistently, reduced F waves, suggesting peripheral nerve dysfunction, of both the peroneal (DL: P = 0.005, N-DL: P = 0.013) and tibial nerves (DL: P = 0.037, N-DL: P = 0.005) were found bilaterally, whereas no changes were observed in nerve ultrasound or other parameters of the NCS of both the upper and lower limbs. In these young healthy males, only the F waves, known to respond to postural changes, were significantly affected by short-term bed rest. These preliminary results suggest that during simulated microgravity, most changes occur at the muscle or central nervous system level. Since the assessment of F waves is common in clinical neurophysiological examinations, caution should be used when testing individuals after prolonged immobility.

Neurological manifestations of COVID-19: A comprehensive literature review and discussion of mechanisms

Several neurological symptoms and complications have been described in association with COVID-19, such as anosmia, ageusia, encephalitis and Guillain-Barré syndrome. Here, we review the literature describing SARS-CoV-2-induced neurological manifestations and provide a comprehensive discussion of proposed mechanisms underlying the neurological pathophysiology. First, we analyse the neuroinvasiveness potential of the coronavirus family based on previous SARS-CoV-1 studies. Then, we describe the current evidence on COVID-19-induced nervous tissue damage, including processes behind brain vasculopathy and cytokine storm. We also discuss in detail anosmia and Guillain-Barré syndrome. Finally, we provide a summarised timeline of the main findings in the field. Future perspectives are presented, and suggestions of further investigations to clarify how SARS-COV-2 can affect the CNS.

[Polyneuropathies during COVID-19 epidemics]

Our review article aimed for analysis of pathogenesis, diagnostyics and treatment of polyneuropathies manifesting in the course of COVID-19. The reasons for hyposmia and taste disturbances are considered in the subjects with this coronavirus infection as well as relationship between these clinical manifestations and severity of the viral infection. Special attention is given to description of autoimmune mechanisms of Guillain-Barré syndrome and polyneuropathies of critical conditions associated with COVID-19. Some data report about clinical deterioration of diabetic and alcoholic neuropathy during the SARS-CoV-2 infection. Inclusion of group B vitamins, together with C and D vitamins, is recommended to the schedules of combined treatment for polyneuropathies in these patients. Early diagnostics of polyneuropathies, especially, Guillain-Barré syndrome, is required during COVID-19 pandemics, thus helping to administer rational therapy and promoting better quality of life in the patients.

Cerebrospinal fluid from COVID-19 patients with olfactory/gustatory dysfunction: A review

Objective

We reviewed the literature on cerebrospinal fluid (CSF) testing in patients with altered olfactory/gustatory function due to COVID-19 for evidence of viral neuroinvasion.

Methods

We performed a systematic review of Medline and Embase to identify publications that described at least one patient with COVID-19 who had altered olfactory/gustatory function and had CSF testing performed. The search ranged from December 1, 2019 to November 18, 2020.

Results

We identified 51 publications that described 70 patients who met inclusion criteria. Of 51 patients who had CSF SARS-CoV-2 PCR testing, 3 (6%) patients had positive results and 1 (2%) patient had indeterminate results. Cycle threshold (Ct; the number of amplification cycles required for the target gene to exceed the threshold, which is inversely related to viral load) was not provided for the patients with a positive PCR. The patient with indeterminate results had a Ct of 37 initially, then no evidence of SARS-CoV-2 RNA on repeat testing. Of 6 patients who had CSF SARS-CoV-2 antibody testing, 3 (50%) were positive. Testing to distinguish intrathecal antibody synthesis from transudation of antibodies to the CSF via breakdown of the blood-brain barrier was performed in 1/3 (33%) patients; this demonstrated antibody transmission to the CSF via transudation.

Conclusion

Detection of SARS-CoV-2 in CSF via PCR or evaluation for intrathecal antibody synthesis appears to be rare in patients with altered olfactory/gustatory function. While pathology studies are needed, our review suggests it is unlikely that these symptoms are related to viral neuroinvasion.

Cerebrospinal fluid and serum interleukins 6 and 8 during the acute and recovery phase in COVID-19 neuropathy patients

This case series describes three patients affected by severe acute respiratory syndrome coronavirus 2, who developed polyradiculoneuritis as a probable neurological complication of coronavirus disease 2019 (COVID-19). A diagnosis of Guillain Barré syndrome was made on the basis of clinical symptoms, cerebrospinal fluid analysis, and electroneurography. In all of them, the therapeutic approach included the administration of intravenous immunoglobulin (0.4 gr/kg for 5 days), which resulted in the improvement of neurological symptoms. Clinical neurophysiology revealed the presence of conduction block, absence of F waves, and in two cases, a significant decrease in amplitude of compound motor action potential cMAP. Due to the potential role of inflammation on symptoms development and prognosis, interleukin-6 (IL-6) and IL-8 levels were measured in serum and cerebrospinal fluid during the acute phase, while only serum was tested after recovery. Both IL-6 and IL-8 were found increased during the acute phase, both in the serum and cerebrospinal fluid, whereas 4 months after admission (at complete recovery), only IL-8 remained elevated in the serum. These results confirm the inflammatory response that might be linked to peripheral nervous system complications and encourage the use of IL-6 and IL-8 as prognostic biomarkers in COVID-19.

Systemic and organ-specific immune-related manifestations of COVID-19

Immune-related manifestations are increasingly recognized conditions in patients with COVID-19, with around 3,000 cases reported worldwide comprising more than 70 different systemic and organ-specific disorders. Although the inflammation caused by SARS-CoV-2 infection is predominantly centred on the respiratory system, some patients can develop an abnormal inflammatory reaction involving extrapulmonary tissues. The signs and symptoms associated with this excessive immune response are very diverse and can resemble some autoimmune or inflammatory diseases, with the clinical phenotype that is seemingly influenced by epidemiological factors such as age, sex or ethnicity. The severity of the manifestations is also very varied, ranging from benign and self-limiting features to life-threatening systemic syndromes. Little is known about the pathogenesis of these manifestations, and some tend to emerge within the first 2 weeks of SARS-CoV-2 infection, whereas others tend to appear in a late post-infectious stage or even in asymptomatic patients. As the body of evidence comprises predominantly case series and uncontrolled studies, diagnostic and therapeutic decision-making is unsurprisingly often based on the scarcely reported experience and expert opinion. Additional studies are required to learn about the mechanisms involved in the development of these manifestations and apply that knowledge to achieve early diagnosis and the most suitable therapy.

The course of COVID-19 infection in patients with multiple sclerosis-The experience of one center based on the population of Upper Silesia

Background

It is suspected that patients with multiple sclerosis (MS) are at greater risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection due to disability and immunotherapy. The relationship between MS and coronavirus disease 2019 (COVID-19) is uncertain. The aim of the study was to collect and analyze this relationship.

Methods

All MS patients of the Neurological Outpatient Clinic in Zabrze, Poland, were regularly questioned for the symptoms of COVID-19 and contact with an infected person. Patients that presented with COVID-19 symptoms or confirmed contact with an infected person were referred for the COVID-19 test. All patients with confirmed SARS-CoV-2 infection (n = 41) were included in the analysis. Medical records of the study group were analyzed. Patient condition was monitored in the outpatient clinic after recovery. In 26 subjects, additional examinations, including brain magnetic resonance imaging (MRI), electroneurography (ENG), electroencephalography (EEG), color duplex Doppler (CDD), visual evoked potentials (VEPs), brainstem auditory evoked potentials (BAEPs) and psychological assessment were performed following recovery.

Results

Only one patient required hospitalization during COVID-19 infection, whereas 87.80% of patients did not require treatment for COVID-19. In all patients, C-reactive protein (CRP) levels were below 10 mg/L. In 2.44% of patients, oxygen partial pressure was below 95%. In most MS patients, the results of further examinations after COVID-19 infection were similar to those prior to infection. Psychological assessment revealed that anxiety was found in 42.31% of patients.

Conclusions

A mild course of COVID-19 in MS patients seems common despite disease-modifying drug treatment and disability. Self-isolation is recommended to reduce the number of infected patients. COVID-19 infection did not worsen the course of MS in most subjects. Patients with MS may require additional psychological support during the pandemic due to their susceptibility to anxiety.

Axonal Guillain-Barre syndrome associated with SARS-CoV-2 infection in a child

The relation between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and demyelinating Guillain-Barre syndrome (GBS) has been defined. We aim to report the clinical features of a child with axonal GBS associated with SARS-CoV-2. A 6-year-old male presented with symmetric ascending paralysis progressed over a 4-day course and 2 days of fever. He had bilateral lower and upper limb flaccid weakness of 1/5 with absent deep tendon reflexes. He had severe respiratory muscle weakness requiring invasive mechanical ventilation. On admission, SARS-CoV-2 returned as positive by real-time polymerase chain reaction on a nasopharyngeal swab. Cerebrospinal fluid analysis showed elevated protein without pleocytosis. He was diagnosed with GBS associated with SARS-CoV-2 infection. The nerve conduction study was suggestive of acute motor axonal neuropathy. Ten consecutive therapeutic plasma exchange sessions with 5% albumin replacement followed by four sessions on alternate days were performed. On Day 12, methylprednisolone (30 mg/kg/day for 5 days) was given. On Day 18, intravenous immunoglobulin (2 g/kg/day) was given and repeated 14 days after due to severe motor weakness. On Day 60, he was discharged from the hospital with weakness of neck flexor and extensor muscles of 3/5 and the upper limbs and the lower limbs of 2/5 on home-ventilation. Our patient is considered to be the youngest patient presenting with a possible para-infectious association between axonal GBS and SARS-CoV-2 infection. The disease course was severe with a rapid progression, an earlier peak, and prolonged duration in weakness as expected in axonal GBS.

Prevalence, clinical characteristics and outcomes of Guillain-Barré syndrome spectrum associated with COVID-19: A systematic review and meta-analysis

Background and purpose

Mounting evidence supports an association between Guillain−Barré syndrome spectrum (GBSs) and severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. However, GBSs in the setting of coronavirus disease 2019 (COVID‐19) remains poorly characterized, whilst GBSs prevalence amongst COVID‐19 patients has not been previously systematically evaluated using a meta‐analytical approach.

Methods

A systematic review and meta‐analysis of observational cohort and case series studies reporting on the occurrence, clinical characteristics and outcomes of patients with COVID‐19‐associated GBSs was performed. A random‐effects model was used to calculate pooled estimates and odds ratios (ORs) with corresponding 95% confidence intervals (CIs), compared to non‐COVID‐19, contemporary or historical GBSs patients.

Results

Eighteen eligible studies (11 cohorts, seven case series) were identified including a total of 136,746 COVID‐19 patients. Amongst COVID‐19 patients, including hospitalized and non‐hospitalized cases, the pooled GBSs prevalence was 0.15‰ (95% CI 0%–0.49‰; I² = 96%). Compared with non‐infected contemporary or historical controls, patients with SARS‐CoV‐2 infection had increased odds for demyelinating GBSs subtypes (OR 3.27, 95% CI 1.32%–8.09%; I² = 0%). In SARS‐CoV‐2‐infected patients, olfactory or concomitant cranial nerve involvement was noted in 41.4% (95% CI 3.5%–60.4%; I² = 46%) and 42.8% (95% CI 32.8%–53%; I² = 0%) of the patients, respectively. Clinical outcomes including in‐hospital mortality were comparable between COVID‐19 GBSs patients and non‐infected contemporary or historical GBSs controls.

Conclusion

GBSs prevalence was estimated at 15 cases per 100,000 SARS‐CoV‐2 infections. COVID‐19 appears to be associated with an increased likelihood of GBSs and with demyelinating GBSs variants in particular.