Functional neurological disorder after COVID-19 vaccination

Opinions and experience of neurologists and neurology trainees in Saudi Arabia on functional neurological disorders: a survey based study

BACKGROUND

Functional Neurological Disorder (FND) is commonly encountered in clinical practice, causing functional impairment and poor quality of life. As there is limited data from Saudi Arabia, our study aims to explore the experience and opinions of Saudi neurologists and neurology trainees regarding FND.

METHODS

In our cross-sectional observational study, we included 100 neurology consultants and trainees. Data was collected using an online questionnaire from March to August 2023.

RESULTS

A total of one hundred neurologists participated in the survey. Although 41% of physicians encountered FND patients on a weekly basis or more frequently, only 41.7% of trainees reported receiving dedicated lectures on FND. Furthermore, only 46% of respondents felt comfortable providing a clear explanation of the FND diagnosis to their patients. While the majority (64%) used the term "Functional Neurological Disorder" in medical documentation, only 43% used this term when communicating the diagnosis to patients, with the terminology varying widely. Clinicians emphasized that inconsistent and variable neurological examinations were key indicators raising diagnostic suspicion, which aligns with the recommended reliance on detailed clinical history and neurological examination. Lastly, 61% of physicians stated that their approach to patients with FND lacked a structured management plan.

CONCLUSION

Our study findings emphasize that FND is commonly encountered in clinical practice and reveal a significant lack of targeted education on FND for neurology trainees. Enhancing educational programs for both trainees and practicing neurologists on this prevalent neurological condition is essential for improving patient care and outcomes.

Clinical characteristics of motor functional neurological disorder manifesting as limb weakness after vaccination against coronavirus disease 2019: A case series

Background

The characteristics of functional limb weakness (FLW) as one of the manifestations of functional neurological disorder after vaccination against coronavirus disease 2019 (COVID-19) remain controversial.

Methods

In this descriptive case series, we aimed to elucidate the characteristics of Japanese patients with FLW who claimed muscle weakness after COVID-19 vaccination among patients who visited our outpatient clinic between 1 June 2021 and 31 December 2022.

Results

Nine patients were diagnosed with FLW (mean age: 30.8 years), including two men and seven women. Seven patients were vaccinated with the BioNTech/Pfizer vaccine and two with the mRNA-1273 Moderna vaccine. All patients demonstrated various positive signs for FLW. Magnetic resonance imaging or computed tomography indicated no abnormality that could explain their symptoms. At the time of the clinic visit, five patients were treated for psychiatric disorders, including depression, insomnia, attention-deficit hyperactivity disorder, and Asperger's syndrome. Muscle weakness spread to the limbs beyond the vaccinated arm in seven patients.

Conclusions

We describe the basic characteristics of FLW in Japanese patients after COVID-19 vaccination. Further recognition of these characteristics could aid the diagnosis of FLW by physicians allowing them to support these patients effectively.

Acute encephalomyelitis in a 52-year-old male post messenger ribonucleic acid severe acute respiratory syndrome coronavirus 2 vaccination: a case report

BACKGROUND

Acute disseminated encephalomyelitis is a well-known, but rare, side effect of some vaccines, or symptom following a febrile illness.

CASE

A 69-year-old, otherwise healthy Hispanic male presented with acute fever, confusion, and later progressive weakness after receiving the first dose of the mRNA-1273 (Moderna) severe acute respiratory syndrome coronavirus 2 vaccine. Considering the progressive deterioration of the patient, despite being on multiple immunosuppressive agents, a brain biopsy was obtained, which revealed nonspecific meningoencephalitis.

CONCLUSION

In this case, we highlight the need for a regulatory framework to assist clinicians and patients with coverage of treatment for acute disseminated encephalomyelitis. The use of intravenous immunoglobulin in conjunction with glucocorticoids seems to be an effective treatment option.

Functional neurological disorder: Clinical manifestations and comorbidities; an online survey

Functional Neurological Disorder (FND) is common and is often accompanied by multiple comorbid symptoms and conditions. There have been no large-scale studies exploring the change of its clinical manifestations and comorbidities. We used an online survey to assess FND patient characteristics, changes to fatigue, sleep and pain and comorbid symptoms and diagnoses, as well as treatment strategies. The survey was shared via the charities FND Action and FND Hope. 527 participants were included in the analysis. Most (97.3%) reported experiencing more than one core FND symptom. Many respondents reported associated pain (78.1%), fatigue (78.0%) and sleep disturbances (46.7%) before FND diagnosis which often increased thereafter. Rates of obesity were higher (36.9%) than in the general population. Obesity was associated with increased pain, fatigue and sleep difficulties. There was frequent weight gain after diagnosis. 50.0% of participants reported having other diagnoses prior to FND, while in 43.3% new comorbidities arise after FND diagnosis. Many respondents reported being dissatisfied with their care, expressing a wish for further follow-up from mental health (32.7%) and/or neurological services (44.3%). This large online survey further supports the phenotypic complexity of FND. High rates of pain, fatigue and sleep disturbance exist before diagnosis but monitoring for change is worthwhile. Our study identified major gaps in service provision; we highlight the importance of an open mind regarding change in symptoms; this could aid the early identification and management of co-morbidities, including obesity and migraine, which possibly have a negative impact on FND.

A review of neurological side effects of COVID-19 vaccination

Following the COVID-19 virus epidemic, extensive, coordinated international research has led to the rapid development of effective vaccines. Although vaccines are now considered the best way to achieve collective safety and control mortality, due to the critical situation, these vaccines have been issued the emergency use licenses and some of their potential subsequence side effects have been overlooked. At the same time, there are many reports of side effects after getting a COVID-19 vaccine. According to these reports, vaccination can have an adverse event, especially on nervous system. The most important and common complications are cerebrovascular disorders including cerebral venous sinus thrombosis, transient ischemic attack, intracerebral hemorrhage, ischemic stroke, and demyelinating disorders including transverse myelitis, first manifestation of MS, and neuromyelitis optica. These effects are often acute and transient, but they can be severe and even fatal in a few cases. Herein, we have provided a comprehensive review of documents reporting neurological side effects of COVID-19 vaccines in international databases from 2020 to 2022 and discussed neurological disorders possibly caused by vaccination.

Co-VAN study: COVID-19 vaccine associated neurological diseases- an experience from an apex neurosciences centre and review of the literature

BACKGROUND

Recent studies have shown various neurological adverse events associated with COVID-19 vaccine.

OBJECTIVE

We aimed to retrospectively review and report the neurological diseases temporally associated with COVID-19 vaccine.

METHODS

We performed a retrospective chart review of admitted patients from 1st February 2021 to 30th June 2022. A total of 4672 medical records were reviewed of which 51 cases were identified to have neurological illness temporally associated with COVID-19 vaccination.

RESULTS

Out of 51 cases, 48 had probable association with COVID-19 vaccination while three had possible association. Neurological spectrum included CNS demyelination (n = 39, 76.5 %), Guillain-Barré-syndrome (n = 3, 5.9 %), stroke (n = 6, 11.8 %), encephalitis (n = 2, 3.9 %) and myositis (n = 1, 2.0 %). Female gender had a greater predisposition (F:M, 1.13:1). Neurological events were more commonly encountered after the first-dose (n = 37, 72.5%). The mean latency to onset of symptoms was 13.2 ± 10.7 days after the last dose of vaccination. COVIShield (ChAdOx1) was the most commonly administered vaccine (n = 43, 84.3 %). Majority of the cases with demyelination were seronegative (n = 23, 59.0 %) which was followed by anti-Myelin oligodendrocyte-glycoprotein associated demyelination (MOGAD) (n = 11, 28.2 %) and Neuromyelitis optica (NMOSD) (n = 5, 12.8 %). Out of 6 Stroke cases, 2 cases (33.3 %) had thrombocytopenia and coagulopathy. At discharge, 25/51 (49.0 %) of the cases had favourable outcome (mRS 0 to 1). Among six patients of stroke, only one of them had favourable outcome.

CONCLUSION

In this series, we describe the wide variety of neurological syndromes temporally associated with COVID-19 vaccination. Further studies with larger sample size and longer duration of follow-up are needed to prove or disprove causality association of these syndromes with COVID-19 vaccination.

Bell's Palsy and COVID-19 Vaccines: A Systematic Review and Meta-Analysis

INTRODUCTION

Once the COVID-19 pandemic was declared, the world was waiting for the clue that would be able to cut down the progression of the disease. Vaccines play a crucial role in reducing the disease and saving many people worldwide. However, there are several side effects of these vaccines, like pain, fatigue, fever, and neurological defects like Bell's palsy. In this systematic review, we presented evidence about the occurrence of Bell's palsy followed by COVID-19 vaccination.

METHODS

We searched PubMed, SCOPUS, EBSCO, and Web of Science (WOS) from inception till October 2022. The quality assessment was conducted using the Joanna Briggs Institute, National Institute of Health, and Newcastle-Ottawa. The analysis was conducted on SPSS.

RESULTS

Thirty-five records were involved in our study. The results of our cases revealed that most of the patients (62.8%) experienced unilateral facial paralysis. Also, the majority of the cases were reported after the first dose, and most cases were after Pfizer, AstraZeneca, and Sputnik V vaccines, respectively. The patients who were treated with corticosteroids, IVIG, and anti-viral drugs, showed marked recovery afterward.

CONCLUSION

The rate ratio of Bell's palsy after COVID-19 vaccination was 25.3 per 1,000,000. The ratio was higher after the first dose compared to the second dose and was higher among those who took Oxford/AstraZeneca vaccine compared to other vaccines. However, this condition was reported in a small number of cases among a large number of vaccinated people worldwide. It is important to note that the benefits of getting vaccinated far outweigh any potential risks.

Functional Neurological Disorder-Old Problem New Perspective

Functional neurological disorder (FND) is a common issue in the pediatric population. The concept and our understanding of functional neurological disorders have changed over the past years, and new etiologic models and treatment plans have been explored. Knowledge about FND in the pediatric population, however, is lacking. The aim of this review is to provide an update on pediatric functional neurological disorder. We conducted a literature search of PubMed and SCOPUS databases and reviewed a total of 85 articles to gain insight into the current understanding of FND etiology, diagnosis, treatment, and prognosis in children and adolescents. Functional and high resolution MRI revealed abnormal connectivity and structural changes in patients with functional symptoms. The diagnostic criteria no longer require the presence of a psychological factor and instead focus on a rule-in diagnosis. Treatment of FND includes a clear communication of the diagnosis and the support of a multidisciplinary team. Although FND typically has a poor prognosis, better outcomes appear to have been achieved in children and young adults. We conclude that pediatric functional neurological disorder is a prevalent pathology and that this patient population has additional specific needs compared to the adult population.

Neurological Complications Following COVID-19 Vaccination

PURPOSE OF REVIEW

A variety of neurological complications have been reported following the widespread use of the COVID-19 vaccines which may lead to vaccine hesitancy and serve as a major barrier to the public health aim of achieving protective herd immunity by vaccination. In this article, we review the available evidence regarding these neurological adverse events reported, to provide clarity regarding the same so that unfounded fears maybe put to rest.

RECENT FINDINGS

There is a greater than expected occurrence of severe neurological adverse events such as cortical sinus venous thrombosis, Bell's palsy, transverse myelitis, and Guillain-Barré syndromes along with other common effects such as headaches following different kinds of COVID-19 vaccination. Precipitation of new onset demyelinating brain lesions with or without detection of specific antibodies and worsening of pre-existing neurological disorders (like epilepsy, multiple sclerosis) are also a matter of great concern though no conclusive evidence implicating the vaccines is available as of now. The COVID-19 pandemic is far from being over. Till such time that a truly effective anti-viral drug is discovered, or an appropriate therapeutic strategy is developed, COVID-appropriate behavior and highly effective mass vaccination remain the only weapons in our armamentarium to fight this deadly disease. As often occurs with most therapeutic means for the treatment and prevention of any disease, vaccination against COVID-19 has its hazards. These range from the most trivial ones like fever, local pain and myalgias to several potentially serious cardiac and neurological complications. The latter group includes conditions like cerebral venous thrombosis (curiously often with thrombocytopenia), transverse myelitis and acute inflammatory demyelinating polyneuropathy amongst others. Fortunately, the number of reported patients with any of these serious complications is far too low for the total number of people vaccinated. Hence, the current evidence suggests that the benefits of vaccination far outweigh the risk of these events in majority of the patients. As of now, available evidence also does not recommend withholding vaccination in patients with pre-existing neurological disorders like epilepsy and MS, though adenoviral vaccines should be avoided in those with history of thrombotic events.

COVID-19 Still Surprising Us-A Rare Movement Disorder Induced by Infection

BACKGROUND

Many neurological manifestations are part of COVID-19 infections, including movement disorders, but a clinical picture closely resembling stiff-person syndrome has not yet been described.

CASE PRESENTATION

We report a case of a stiff-person-like syndrome in the context of COVID-19 infection. A 79-year-old woman, with no prior history of diseases, presented global reversible stiffness associated with SARS-CoV-2 infection. We aim to shed light on several particularities regarding this clinical picture and its evolution in close relationship with the infectious disease progression, with full regression of symptoms and signs once the infectious process ceased. The impairment of speech and motility caused the wrong diagnosis of stroke in the Emergency Room. In addition, we would also like to emphasize the concomitant rhabdomyolysis, closely linked to the grade of muscle rigidity.

CONCLUSIONS

We would like to raise awareness regarding this clinical setting and its association with SARS-COV-2 infection, to aid in its future recognition and management. To our knowledge, this is the first case of a stiff-person-like syndrome to be described in association with COVID-19 infection.

Brain perfusion single photon emission computed tomography abnormality in MRI-negative stroke-like patients post COVID-19 vaccination

Stroke-like symptoms after COVID-19 vaccination was thought to be functional if there was no anatomical image abnormality. We aimed to analyze brain perfusion changes in these patients. A case-control study of brain perfusion single photon emission computed tomography (SPECT) of 12 vaccinated patients with left-sided stroke-like symptoms were compared with 12 age- and gender-matched normal interictal brain SPECTs using voxel-based analysis. Significant hyperperfusion was seen on the right side in postcentral, inferior parietal, mid temporal, parahippocampal, and caudate regions, and on the left side in the thalamus, hippocampus, and mid temporal areas. In addition, there were hypoperfused bilateral superior frontal gyri and right mid/posterior cingulate cortex (Family-wise-error corrected p-values  < .05). Both hypoperfusion and hyperperfusion in the brain are demonstrated. We hypothesize that these findings might be the result of the functional neurological disorder. However, based on other previous studies, circulating spike protein in the patients' plasma early after vaccination might also be the cause.

Diagnostic challenges of functional neurological disorders after covid-19 disease or vaccination: case series and review of the literature

BACKGROUND

Functional neurological disorders have rarely been described in patients recovering from Covid-19 or after vaccination but they are probably under diagnosed.

MATERIAL AND METHODS

Six patients referred for rehabilitation of persistent symptoms and/or sequelae of Coronavirus disease 2019 (COVID-19) were diagnosed with functional neurological disorders. A literature review was conducted to identify reported cases of functional neurological disorders after Covid-19 infection or vaccination.

RESULTS

In the current case series, patients diagnosed with functional neurological disorders presented high variability of clinical symptoms including hemiplegia, lower limb unilateral or bilateral paralysis, myoclonus, dystonia, tremor and sensory impairment. Four patients were young females with mild Covid-19 infection without hospital admission. Their neurological symptoms developed over the course of 4 weeks after the beginning of Covid-19 symptoms or vaccine administration with normal ancillary exams. One patient presented overlapping functional neurological symptoms and mild impairment of the left common peroneal nerve after prolonged ICU stay. In addition, all patients in our case series reported other non-motor symptoms such as fatigue, cognitive impairment and diffuse pain or dysesthesia, which are compatible with post Covid-19 condition.

CONCLUSIONS

It is important that clinicians recognize functional neurological symptoms and consider it as a differential diagnosis in patients with neurological complications of Covid-19 infection and vaccination.

Neurological manifestations associated with COVID-19 vaccine

INTRODUCTION

Coronavirus disease 2019 (COVID-19) has spread rapidly, giving rise to a pandemic, causing significant morbidity and mortality. In this context, many vaccines have emerged to try to deal with this disease.

OBJECTIVE

To review the reported cases of neurological manifestations after the application of COVID-19 vaccines, describing clinical, analytical and neuroimaging findings and health outcomes.

METHODS

We carried out a review through bibliographic searches in PubMed.

RESULTS

We found 86 articles, including 13 809 patients with a wide spectrum of neurological manifestations temporally associated with COVID-19 vaccination. Most occurred in women (63.89%), with a median age of 50 years. The most frequently reported adverse events were Bell's palsy 4936/13 809 (35.7%), headache (4067/13 809), cerebrovascular events 2412/13 809 (17.47%), Guillain-Barré syndrome 868/13 809 (6.28%), central nervous system demyelination 258/13 809 (1.86%) and functional neurological disorder 398/13 809 (2.88%). Most of the published cases occurred in temporal association with the Pfizer vaccine (BNT162b2), followed by the AstraZeneca vaccine (ChAdOX1-S).

CONCLUSIONS

It is not possible to establish a causal relationship between these adverse events and COVID-19 vaccines with the currently existing data, nor to calculate the frequency of appearance of these disorders. However, it is necessary for health professionals to be familiar with these events, facilitating their early diagnosis and treatment. Large controlled epidemiological studies are necessary to establish a possible causal relationship between vaccination against COVID-19 and neurological adverse events.

[NEUROLOGICAL MANIFESTATIONS ASSOCIATED WITH COVID-19 VACCINE]

INTRODUCTION

Coronavirus disease 2019 (COVID-19) has spread rapidly, giving rise to a pandemic, causing significant morbidity and mortality. In this context, many vaccines have emerged to try to deal with this disease.

OBJECTIVE

To review the reported cases of neurological manifestations after the application of COVID-19 vaccines, describing clinical, analytical and neuroimaging findings and health outcomes.

METHODS

We carried out a review through bibliographic searches in PubMed.

RESULTS

We found 86 articles, including 13,809 patients with a wide spectrum of neurological manifestations temporally associated with COVID-19 vaccination. Most occurred in women (63.89%), with a median age of 50 years. The most frequently reported adverse events were Bell's palsy 4936/13809 (35.7%), headache (4067/13809), cerebrovascular events 2412/13809 (17.47%), Guillain-Barré syndrome 868/13809 (6.28%), central nervous system demyelination 258/13809 (1.86%) and functional neurological disorder 398/13809 (2.88%). Most of the published cases occurred in temporal association with the Pfizer vaccine (BNT162b2), followed by the AstraZeneca vaccine (ChAdOX1 nCoV-19).

CONCLUSIONS

It is not possible to establish a causal relationship between these adverse events and COVID-19 vaccines with the currently existing data, nor to calculate the frequency of appearance of these disorders. However, it is necessary for health professionals to be familiar with these events, facilitating their early diagnosis and treatment. Large controlled epidemiological studies are necessary to establish a possible causal relationship between vaccination against COVID-19 and neurological adverse events.

Safety of COVID-19 Vaccines: Spotlight on Neurological Complications

The COVID-19 pandemic has led to unprecedented demand on the global healthcare system. Remarkably, at the end of 2021, COVID-19 vaccines received approvals for human use in several countries worldwide. Since then, a solid base for response in the fight against the virus has been placed. COVID-19 vaccines have been shown to be safe and effective drugs. Nevertheless, all kinds of vaccines may be associated with the possible appearance of neurological complications, and COVID-19 vaccines are not free from neurological side effects. Neurological complications of COVID-19 vaccination are usually mild, short-duration, and self-limiting. However, severe and unexpected post-vaccination complications are rare but possible events. They include the Guillain-Barré syndrome, facial palsy, other neuropathies, encephalitis, meningitis, myelitis, autoimmune disorders, and cerebrovascular events. The fear of severe or fatal neurological complications fed the “vaccine hesitancy” phenomenon, posing a vital communication challenge between the scientific community and public opinion. This review aims to collect and discuss the frequency, management, and outcome of reported neurological complications of COVID-19 vaccines after eighteen months of the World Health Organization’s approval of COVID-19 vaccination, providing an overview of safety and concerns related to the most potent weapon against the SARS-CoV-2.

Good recovery of immunization stress-related responses presenting as a cluster of stroke-like events following CoronaVac and ChAdOx1 vaccinations

Background

Immunization stress-related responses presenting as stroke-like symptoms could develop following COVID-19 vaccination. Therefore, this study aimed to describe the clinical characteristics of immunization stress-related responses causing stroke-like events following COVID-19 vaccination in Thailand.

Methods

We conducted a retrospective study of the secondary data of reported adverse events after COVID-19 immunization that presented with neurologic manifestations. Between March 1 and July 31, 2021, we collected and analyzed the medical records of 221 patients diagnosed with stroke-like symptoms following immunization. Two majority types of vaccines were used at the beginning of the vaccination campaign, including CoronaVac (Sinovac) or ChAdOx1 (AstraZeneca). Demographic and medical data included sex, age, vaccine type, sequence dose, time to event, laboratory data, and recovery status as defined by the modified Rankin score. The affected side was evaluated for associations with the injection site.

Results

Overall, 221 patients were diagnosed with immunization stress-related responses (stroke-like symptoms) following CoronaVac (Sinovac) or ChAdOx1 (AstraZeneca) vaccinations. Most patients (83.7%) were women. The median (interquartile range) age of onset was 34 (28–42) years in patients receiving CoronaVac and 46 (33.5–60) years in those receiving ChAdOx1. The median interval between vaccination and symptom onset for each vaccine type was 60 (16–960) min and 30 (8.8–750) min, respectively. Sensory symptoms were the most common symptomology. Most patients (68.9%) developed symptoms on the left side of the body; 99.5% of the patients receiving CoronaVac and 100% of those receiving ChAdOx1 had a good outcome (modified Rankin scores ≤2, indicating slight or no disability).

Conclusions

Immunization stress-related responses presenting as stroke-like symptoms can develop after COVID-19 vaccination. Symptoms more likely to occur on the injection side are transient (i.e., without permanent pathological deficits). Public education and preparedness are important for administering successful COVID-19 vaccination programs.

Patients with post-COVID-19 vaccination facial palsy: To boost or not to boost?

A possible association between Bell’s palsy and COVID-19 vaccination has been suggested. While it is likely that COVID-19 vaccine recipients from the general population do have a slightly increased risk of developing Bell’s palsy, there are little data regarding this risk in individuals with a history of disease. Gaining a better understanding of this association is particularly important for informing evidence-based recommendations regarding future booster shots in subjects who developed Bell’s palsy as a side effect of vaccination, or as a result of SARS-CoV-2 infection. We previously described the first case of COVID-19 vaccine-related Bell’s palsy; here we report an 18-month clinical and electromyographic follow-up and discuss the implications of receiving further vaccine doses in patients with positive disease history.

Do demographic and clinical features and comorbidities affect the risk of spread to an additional body site in functional motor disorders?

The aim of this study is to assess changes in the body distribution and the semeiology of functional motor disorder (FMD) in patients who reported only one or more than one body site affected at FMD onset. Data were obtained from the Italian Registry of Functional Motor Disorders, which included patients with a diagnosis of clinically definite FMDs. The relationship between FMD features and spread to other body sites was estimated by multivariate Cox regression analysis. We identified 201 (49%) patients who reported only one body site affected at FMD onset and 209 (51%) who reported multiple body sites affected at onset. FMD spread from the initial site to another site in 43/201 (21.4%) patients over 5.7 ± 7.1 years in those with only one site affected at FMD onset; FMD spread to an another body site in 29/209 (13.8%) over 5.5 ± 6.5 years. The spread of FMD was associated with non-motor functional symptoms and psychiatric comorbidities only in the patients with one body site affected at FMD onset. Our findings provide novel insight into the natural history of FMD. The number of body sites affected at onset does not seem to have a consistent influence on the risk of spread. Furthermore, our findings suggest that psychiatric comorbidities and non-motor functional symptoms may predict the spread of FMD symptoms, at least in patients with one body site affected at onset.

Inactivated COVID-19 vaccine induced acute stroke-like focal neurologic symptoms: a case series

Background

A subgroup of individuals experienced stroke-like symptoms after receiving an inactivated COVID-19 vaccine. We present clinical characteristics, neuroimaging, and outcome of these patients.

Methods

Medical personals who had neurological symptoms after receiving inactivated COVID-19 vaccine were enrolled. Clinical, laboratory investigation and neuroimaging were collected. Subjects were prospectively followed-up on clinical and neuroimaging to detect brain parenchymal or cerebrovascular abnormality.

Results

Nineteen out of 385 subjects (4.9%) developed neurological symptoms after vaccination. There was a female predominance (89.5%) with mean age of 34 ± 7.5 years. Majority of patients (52.6%) had symptoms within 60 min after vaccination. The most common neurological symptoms were numbness (94.7%) followed by headache (52.6%) and weakness (47.4%). The most common neurological signs were sensory deficit (79%) followed by motor weakness (52.6%) and tongue deviation (26.3%). Recurrent headache was observed in most patients (89.5%) during followed up. Serial brain imaging was done in all patients with median follow-up interval of 18 days. There was no evidence of acute brain infarction in any of the patients, 84.2% had no vascular abnormality, 15.8% had transient focal narrowing of cerebral vessels. Outcome was favorable, modified ranking scale 0–1 for all patients at 4 weeks after vaccination.

Conclusions

Transient focal neurological symptoms and deficits can be found after COVID-19 vaccination. However, benefit to stop COVID-19 pandemic by vaccination is outweighed by these seemingly reversible side effects. The pathophysiology underlined these phenomena should be further investigated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02739-6.

Psychiatric adverse reactions to COVID-19 vaccines: A rapid review of published case reports

We aimed to review the available reports of psychiatric adverse reactions to COVID vaccines. Electronic databases such as PubMed and Google scholar were combed to identify relevant reports. We found a total of 11 reports describing 14 cases of psychiatric reactions; these were mostly altered mental states, psychosis, mania, depression, and functional neurological disorder. The index case was commonly a young or middle-aged adult. All reports pertained to the use of either mRNA or vector-based vaccines. Symptom onset was within 10 days of vaccination in all cases; as such, this seems to be a high-risk period warranting vigilance.

Vaccine-induced functional neurological disorders in the Covid-19 era

The large amount of information available to the public regarding vaccines against Covid-19 coupled with pandemic stress and increased somatic attention could potentially precipitate development of functional neurological disorders (FNDs) following vaccination. A growing number of reports indicate that functional symptoms may follow Covid-19 vaccination, similar to those observed with other vaccines previously. We review previously reported cases of FND following vaccination against Covid-19 and present three additional cases. While two patients presented to the Emergency Department with functional movement disorders, one patient presented with protracted limb weakness and sensory dysfunction. The superficial resemblance to Guillain-Barré syndrome, a known but uncommon complication of vaccination prompted an extensive workup. Clinicians need to convey the diagnosis of FND in clear and unequivocal terms to facilitate institution of appropriate therapy and rehabilitation, but importantly also to dispel any doubts in the minds of the public regarding the safety of the available vaccines. Given the presence of significant vaccine hesitancy in many countries, this is critical to the success of the global immunisation effort.

Does Olfactory Dysfunction Correlate with Disease Progression in Parkinson’s Disease? A Systematic Review of the Current Literature

Background. Loss of olfaction is a well-established early feature of Parkinson’s disease (PD). Although olfactory dysfunction has been widely described as a prodromal feature of PD in the literature, whether it can be considered a biomarker of PD progression is still a matter of debate. Objective. The aim of this work is to define the possible relationship between the progression of olfactory dysfunction and other putative clinical hallmarks of PD over time, through a systematic review of the current literature. Methods. We conducted a systematic review of the literature on PubMed from inception to March 2022. We included only longitudinal studies conducted on patients with diagnosis of idiopathic PD who underwent olfactory function testing at baseline and repeated it at least once during follow-up. Results. Among 5740 records identified through database searching, nine longitudinal studies met full criteria and underwent data extraction. Conclusions. Olfaction seemed to decrease over time, albeit with a degree of fluctuation. Moreover, smell detection ability seems to deteriorate more rapidly in the early phase of disease, indicating a possible association with disease progression. More studies are needed to better understand the role of olfaction as a biomarker of PD progression over time.

Neurological and neuropsychological adverse effects of SARS-CoV-2 vaccines - where do we stand?

The devastating characteristic of COVID-19 pandemic calls for immediate and effective solutions to tackle it. Vaccines seem to be the only promising and effective way to fight against the novel coronavirus - even against new mutated variants. Because of the rapid development and distribution of numerous COVID-19 vaccines in different platforms, meticulous evaluation of vaccines' safety is more critical than ever - especially given the fact that most of the candidates have not completed the clinical phase. Therefore, to optimize the vaccines' safety and efficacy, it is highly important to carefully report and scientifically discuss the serious adverse effects following vaccination. In this respect, we discuss different neurological and neuropsychological adverse effects of COVID-19 vaccines including demyelinating diseases, Bell's palsy (BP), cerebrovascular complications, seizures, functional neurological disorders (FNDs), and some other rare adverse events, and hypothetical mechanisms which can lead to the reported side effects. Given the fact that the incidence of such events are rare and most of them are treatable, the current review aims to shed light on how much the relationship between COVID-19 vaccines and these complications can be reliable and provide an insight for future studies with much more meticulous methodologies to discuss the possible correlational or causal relationship between these complications and COVID-19 vaccines and elucidate whether or not the neurological side effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines can count as a considerable threat to public health.

Neurological side effects of SARS-CoV-2 vaccinations

SARS-CoV-2 and adverse reactions to SARS-CoV-2 vaccinations show a tropism for neuronal structures and tissues. This narrative review was conducted to collect and discuss published data about neurological side effects of SARS-CoV-2 vaccines in order to discover type, frequency, treatment, and outcome of these side effects. The most frequent neurological side effects of SARS-CoV-2 vaccines are headache, Guillain-Barre syndrome (GBS), venous sinus thrombosis (VST), and transverse myelitis. Other neurological side effects occur in a much lower frequency. Neurological side effects occur with any of the approved vaccines but VST particularly occurs after vaccination with vector-based vaccines. Treatment of these side effects is not at variance from similar conditions due to other causes. The worst outcome of these side effects is associated with VST, why it should not be missed and treated appropriately in due time. In conclusion, safety concerns against SARS-CoV-2 vaccines are backed by an increasing number of studies reporting neurological side effects. The most frequent of them are headache, GBS, VST, and transverse myelitis. Healthcare professionals, particularly neurologists involved in the management of patients having undergone SARS-CoV-2 vaccinations, should be aware of these side effects and should stay vigilant to recognize them early and treat them adequately.

Spectrum of neurological complications following COVID-19 vaccination

COVID-19 vaccines have brought us a ray of hope to effectively fight against deadly pandemic of COVID-19 and hope to save lives. Many vaccines have been granted emergency use authorizations by many countries. Post-authorization, a wide spectrum of neurological complications is continuously being reported following COVID-19 vaccination. Neurological adverse events following vaccination are generally mild and transient, like fever and chills, headache, fatigue, myalgia and arthralgia, or local injection site effects like swelling, redness, or pain. The most devastating neurological post-vaccination complication is cerebral venous sinus thrombosis. Cerebral venous sinus is frequently reported in females of childbearing age, generally following adenovector-based vaccination. Another major neurological complication of concern is Bell's palsy that was reported dominantly following mRNA vaccine administration. Acute transverse myelitis, acute disseminated encephalomyelitis, and acute demyelinating polyneuropathy are other unexpected neurological adverse events that occur as result of phenomenon of molecular mimicry. Reactivation of herpes zoster in many persons, following administration of mRNA vaccines, has been also recorded. Considering the enormity of recent COVID-19-vaccinated population, the number of serious neurological events is miniscule. Large collaborative prospective studies are needed to prove or disprove causal association between vaccine and neurological adverse events occurring vaccination.

Qualitative smell/taste disorders as sequelae of acute COVID-19

Background

Qualitative smell/taste disorders (such as phantosmia, parosmia, phantogeusia, and parageusia) have not yet been fully characterized in patients who had COVID-19, whereas quantitative disturbances (i.e., reduction/loss of smell/taste) have been widely investigated.

Objective

To simultaneously assess the presence of both quantitative and qualitative smell/taste dysfunctions in patients who suffered from COVID-19.

Methods

We enrolled 17 consecutive patients who suffered from COVID-19 over the last 6 months and 21 healthy controls, matched for sex and age. After a negative nasopharyngeal swab, the Sniffin’ Sticks Test and the Taste Strips were used to assess olfactory and taste function, respectively. At the same time, the presence of phantosmia, parosmia, phantogeusia, and parageusia was investigated with a standardized questionnaire.

Results

Qualitative disturbances of smell and/or taste were found in 6/17 (35.3%) patients. Phantosmia was reported in 2/17 (11.8%) patients and parosmia in 4/17 (23.5%). There were no significant differences in smell test scores between patients who reported phantosmia and/or parosmia and patients who did not. Phantogeusia was described in 3/17 (17.6%) patients, and parageusia was identified in 4/17 (23.5%) patients. All tested patients were normogeusic.

Conclusion

Around one-third of patients who recover from COVID-19 may have persistent qualitative dysfunction in smell/taste domains. Detection of phantogeusia in long-term COVID-19 patients represents a further novel finding. Further investigation is needed to better characterize the pathophysiology of phantosmia, parosmia, phantogeusia, and parageusia in patients who had COVID-19.