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. 2024 Jun 28;12:1355. Originally published 2023 Oct 18. [Version 2] doi: 10.12688/f1000research.140514.2

Case Report: Bell’s palsy: a neurological manifestation of COVID-19 infection

Amro Abdelrahman 1, Amira Bitar 1, Isra Babiker 1, Fawaz Elgak 1, Mohamed Elgassim 1,a
PMCID: PMC11809692  PMID: 39931161

Version Changes

Revised. Amendments from Version 1

In addition to re-ordering of the references, the following paragraphs/sentences were added/changed based on reviewer recommendations: The relationship between COVID-19 and neurological complications, including facial palsy, is complex and has been the subject of ongoing research. While some cases report facial nerve paralysis occurring within a week of viral symptom onset, there is variability in the reported timeframes. A diagnosis of Bell's palsy potentially related to COVID-19 infection was made. The relationship between COVID-19 and neurological complications, including facial palsy, is complex and has been the subject of ongoing research. While some cases report facial nerve paralysis occurring within a week of viral symptom onset, there is variability in the reported timeframes. various types of neurological manifestations of COVID-19 infection have been reported. Past medical history will be deleted in the second paragraph.

Abstract

Background

Coronavirus (COVID-19) is the causative agent of the most recent pandemic that hit the globe and has been the cause of a vast range of symptoms, including neurological symptoms. Bell’s palsy is an acute peripheral facial paralysis commonly associated with viral infections.

Case presentation

This case report describes a patient with incidental COVID-19 infection that led to acute unilateral peripheral facial paralysis, Bell’s palsy. Our patient is a 35-year-old male with no known comorbidities who was presenting with upper respiratory tract infection symptoms and was found to be positive for COVID-19. Soon after the onset of symptoms, he also developed right-sided facial weakness in association with his symptoms. A thorough examination revealed a peripheral neurological lesion. The diagnosis of Bell’s palsy secondary to COVID-19 virus infection was through the exclusion of other possible causes.

Conclusions

This case report suggests a potential link between Bell’s palsy and COVID-19, highlighting the importance of a comprehensive understanding of the neurological manifestations of COVID-19. Further research is essential to determine the significance of neuropathies in COVID-19 and enhance treatment strategies.

Keywords: COVID-19, Coronavirus, Bell's palsy, Isolated facial neuropathy, Acute peripheral neuropathy

Introduction

Coronavirus (COVID-19) infection has affected millions of people worldwide. It’s an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). People with COVID-19 infection have a wide range of reported symptoms, ranging from a mild cough to acute respiratory syndrome (ARDS). 1 Patients with COVID-19 commonly face complications and potential causes of mortality, including conditions such as sepsis, acute kidney injury, ARDS, acute hypoxic encephalopathy, and acute cardiac injury. 1

A growing number of COVID-19 cases have been associated with facial nerve paralysis, often presenting as the initial symptom or occurring within the first week after the onset of viral symptoms or a positive COVID-19 test. 2

The relationship between COVID-19 and neurological complications, including facial palsy, is complex and has been the subject of ongoing research. While some cases report facial nerve paralysis occurring within a week of viral symptom onset, there is variability in the reported timeframes. 3

Additionally, individuals may experience other neurological complications such as loss of smell (anosmia), altered taste perception (dysgeusia), encephalopathy, Guillain-Barre syndrome, Miller-Fisher syndrome, and polyneuritis cranialis. 4 In this case we’re reporting a case of Bell’s palsy following COVID-19 infection in a previously healthy 35-year-old-male. This case report follows the CARE guidelines. 15

Case presentation

A 35-year-old South Asian male taxi driver with no past medical history presented to the Emergency Department of Hamad General Hospital complaining of a two day history of sudden right-sided facial weakness associated with fever, cough, and sore throat. Three days before admission the patient had gone to a primary health care center due to upper respiratory tract symptoms, and a diagnosis of COVID-19 was made.

Two days later, the patient suddenly developed weakness associated with numbness, drooling saliva while eating and difficulty closing the right eye. He had no other neurologic symptoms and denied ear pain, skin rash, or arthralgia. He had no recent history of travel, or a tick bite. The review of other systems was unremarkable.

At the Emergency Department, his temperature was 37°C, his peripheral pulse rate was 70 bpm, and his respiratory rate was 18 breaths per minute. His oxygen saturation was 98% on room air, blood pressure was 122/74 mmHg. Physical examination revealed the absence of right-sided forehead wrinkles compared to the left, drooping of the right eyelid, and prominent mouth deviation suggestive of right lower motor neuron facial nerve palsy. Careful examination of ears showed dry impacted wax in the right ear with no vesicles. Examination of the parotid gland was unremarkable. Sensation in both upper and lower extremities was intact. No weakness was noted in either the upper or lower limbs. Kernig’s and Brudzinski’s signs were negative. Examination of other systems was unremarkable.

The patient’s complete blood count and basic metabolic panel were within normal ranges. His COVID-19 rapid antigen test was positive. The chest X-ray was unremarkable. A diagnosis of Bell’s palsy potentially related to COVID-19 infection was made, and the patient was discharged and prescribed the following medications:

  • Prednisolone: 20 mg orally (PO) daily for 10 days.

  • Levocetirizine: 5 mg PO daily for 5 days.

  • Gentamicin solution: 0.3% solution, applied twice daily to both eyes for 7 days.

  • Paracetamol: 1,000 mg PO every 6 hours as needed for 5 days.

  • Eye drops: Applied twice daily for 14 days.

He was also referred to a physical therapy clinic. On his four-week follow-up visit, the patient showed no significant improvement. On his 10-week follow up clinic appointment, the patient symptoms showed a significant improvement.

Discussion

Besides the usual and well-known respiratory symptoms, SARS-CoV-2 can affect the peripheral and central nervous systems. Neurological symptoms can be the first manifestation of COVID-19 infection or concurrent respiratory symptoms. A retrospective review reported neurological symptoms in 36.5% of patients. 5

Two different mechanisms could explain the neuropathogenesis of SARS-CoV-2. The first mechanism is due to endothelial damage and the subsequent passing of the virus from the systemic circulation to the cerebral circulation. The alternative mechanism is thought to be due to the direct entering of the virus through the cribriform wall and olfactory bulb, where the olfactory nerve terminates. 6 Using the olfactory pathways, the virus can harm the central nervous system (CNS), which may propagate from neuron to neuron by axonal transport. 7

When glial cells get infected with the virus, the body enters a pro-inflammatory state and releases cytokines. The prolonged exposure to cytokines may lead to nerve damage. 8

Moreover, various types of neurological manifestations of COVID-19 infection have been reported. 9

An observational study conducted in Spain documented cases where COVID-19 was associated with cranial nerve manifestations. In one of these cases, polyneuritis cranialis developed on the third day, while in the other case, Miller Fisher syndrome occurred on the fifth day. 10 A previous study also described a case of an isolated facial paralysis presented after six days in a patient with COVID-19 infection. 2 Our patient experienced a lower motor neuron facial paralysis on the third day of his ongoing COVID-19 infection.

Bell’s palsy is a lower motor neuron impairment of the facial cranial nerve, manifesting acutely as a unilateral facial paralysis. 11 Although the reason for many cases is unidentifiable, the most common cause of peripheral facial palsy is attributed to infections, mainly Herpes Simplex Virus-1 (HSV-1), Varicella Zoster Virus (VZV), and Lyme disease. 3 Our patient denied any recent travel, trauma, insect bite, skin rash, joint pain, itchiness, or tingling sensation in the body. Physical examination was unremarkable, with no skin rash; the outer ear canal was clear, and no signs of meningitis. Causes such as autoimmune and vasculitis were excluded as the patient did not have any systemic findings. Human Immunodeficiency Virus (HIV) infection was also excluded as it is a part of the infectious screening for all people getting their residencies in the country. The patient had a fever, sore throat, and generalized body pain, and his COVID-19 rapid antigen test came positive. Therefore, no other etiologies than COVID-19 infection could be attributed to palsy.

COVID-19 infection is known to present mainly as respiratory symptoms ranging from mild to severe, such as ARDS and fever. 12 In addition, neurological manifestations, including Guillain-Barre syndrome, anosmia/ageusia, encephalopathy, and myelitis, are also encountered. 3 Bell’s palsy is one of the manifestations of COVID-19. Poor prognosis is predicted in patients >60 years of age with systemic problems such as diabetes mellitus, severe pain in the ear, and decreased tear production. Bell’s palsy generally has a good prognosis and recovery rate of 90%. 13 Regarding the treatment, the most used one in facial paralysis is corticosteroids, with high effectiveness rates. 12 Prednisolone’s effect on the facial nerve is by reducing its edema. 14 In our case, the patient had no risk factors for poor prognosis; he was prescribed prednisolone (20 mg) for 10 days and referred to a physiotherapy clinic. His four-week follow-up visit showed no significant change in his condition. However, on his 10-week follow-up clinic visit his weakness improved significantly.

Limitations

The viral screening wasn’t done to rule out all other viral etiologies.

Conclusions

This case report raises the possibility that Bell’s palsy and COVID-19 infection are related. However, to prove the causal association, more cases with epidemiological data are required. For a deeper knowledge of COVID-19 infection, it is crucial to investigate its neurologic symptoms. Therefore, additional research is needed to fully understand the prognostic importance of cranial neuropathies in COVID-19 disease and their natural history and choose the most effective therapy approach.

Key clinical message

Any patient with a fever and neurological symptoms should be evaluated for COVID-19.

Consent

Written informed consent for publication of their clinical details was obtained from the patient.

Acknowledgments

We deeply thank our patient for giving us the chance to share this valuable and scientific information. An earlier version of this article can be found on Authorea (doi: https://doi.org/10.22541/au.166797382.23559879/v1).

Funding Statement

Open Access funding was provided by the Qatar National Library.

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

[version 2; peer review: 2 approved

Data availability

Underlying data

All data underlying the results are available as part of the article and no additional source data are required.

Reporting guidelines

Zenodo: CARE checklist for “Case Report: Bell’s palsy: a neurological manifestation of COVID-19 infection”. https://doi.org/10.5281/zenodo.8359632. 15

Data are available under the terms of the Creative Commons Attribution 4.0 International license (CC-BY 4.0).

References

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F1000Res. 2024 Dec 28. doi: 10.5256/f1000research.168370.r328968

Reviewer response for version 2

Josef Finsterer 1

F1000REs,  Case Report: Bell’s palsy: a neurological manifestation of COVID-19 infection

Abdelrahman et al report a single case of a 35yo male patient with SARS-CoV-2 infection that was complicated by unilateral facial palsy.

Major points:

Facial palsy is a common complications of SC2 infection and vaccinations. This should be added to the limitations

Minor points:

Do not use the term “Bell’s palsy”. It is reserved for idiopathic facial palsy.

Are enough details provided of any physical examination and diagnostic tests, treatment given and outcomes?

Yes

Is the case presented with sufficient detail to be useful for other practitioners?

Yes

Is sufficient discussion included of the importance of the findings and their relevance to future understanding of disease processes, diagnosis or treatment?

Yes

Is the background of the case’s history and progression described in sufficient detail?

Yes

Reviewer Expertise:

neuromuscular

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

F1000Res. 2024 Dec 26. doi: 10.5256/f1000research.168370.r346701

Reviewer response for version 2

Isabel Vilaseca 1

In the treatment section, please explain why the patient required gantamicin in both eyes and levocetiricine. I cannot understand the rationale of this prescription.

In the discussion a paragraph should be included to highlight that the association of Bell's palsy  and COVID-19 is still controversial.

In fact, a recent historical cohort comparison study evaluating the crude incidence of patients diagnosed with Bell's palsy, did not find association between vaccination or COVID-19 infection and the development of Bell's Palsy before and after the pandemic period.

Are enough details provided of any physical examination and diagnostic tests, treatment given and outcomes?

Partly

Is the case presented with sufficient detail to be useful for other practitioners?

Yes

Is sufficient discussion included of the importance of the findings and their relevance to future understanding of disease processes, diagnosis or treatment?

Partly

Is the background of the case’s history and progression described in sufficient detail?

Yes

Reviewer Expertise:

Otorhinolaryngology

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

References

  • 1. : Bell's palsy and COVID-19: A cohort study with historical rate comparison. Acta Otorrinolaringol Esp (Engl Ed) .2024; 10.1016/j.otoeng.2024.07.004 10.1016/j.otoeng.2024.07.004 [DOI] [PubMed] [Google Scholar]
F1000Res. 2024 Jul 16. doi: 10.5256/f1000research.168370.r296810

Reviewer response for version 2

Sohyeon Kim 1

I acknowledge some of the changes made by the authors and I respect the effort.

Are enough details provided of any physical examination and diagnostic tests, treatment given and outcomes?

Partly

Is the case presented with sufficient detail to be useful for other practitioners?

Partly

Is sufficient discussion included of the importance of the findings and their relevance to future understanding of disease processes, diagnosis or treatment?

Partly

Is the background of the case’s history and progression described in sufficient detail?

Partly

Reviewer Expertise:

neuromuscular diseases

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

F1000Res. 2024 May 21. doi: 10.5256/f1000research.153880.r274184

Reviewer response for version 1

Sohyeon Kim 1

I found it as a quite interesting case, but there are several important issues to be checked over in this case report.

First of all, the diagnostic process seemed somewhat insufficient to me. If someone wants to attribute a certain neurologic symptom to be caused by COVID-19, he/she should explain either a causative mechanism or a temporal relationship together with thorough exclusion of other causes.

In the Case presentation section, the author stated as "A diagnosis of Bell's palsy secondary to COVID-19 infection was made". I think this sounds too confirmative since the causative mechanism of COVID-19 triggering Bell's palsy in this case is uncertain. Also, regarding the exclusion of other causes, the case is lacking of objective results from the diagnostic evaluations and the diagnosis mostly depended merely on the implications from clinical symptoms. If the authors had performed any laboratory test about autoimmune etiology or auxiliary diagnostic work up such as nerve conduction study, cranial MRI, and etc., I recommend containing the results in the revised manuscript. If the objective data are unavailable, the author should mention this as a limitation and need to tone down about the diagnostic certainty.  

Secondly, In the Introduction section, the author mentioned "A growing number of COVID-19 cases have been associated with facial nerve paralysis, often presenting as the initial symptom or occurring within the first week after the onset of viral symptoms or a positive COVID-19 test". While I acknowledge that facial paralysis occurred within three days of the COVID-19 diagnosis in the present case and it is close enough to allege their temporal relationship, the above sentence sounds to me as if facial palsy and COVID-19 need to occur within one week from each other to generally define the temporal relationship. As there have been controversy among researchers regarding the definition of the time interval as evidence of a specific temporal relationship between COVID-19 and neurological complications, I suggest that the authors supplements the manuscript with additional references to clarify the definition of the temporal relationship between facial palsy and COVID-19.

Also, I am not sure if we could adopt the same prognostic factors of Bell's palsy in COVID-19 related cases as the authors mentioned in Discussion section. I think the clinical characteristics and prognostic factors specifically of COVID-19 related Bell's palsy cases should be investigated and explained with supplementary references. 

Additionally, there are several minor comments for the manuscript as well. 

- In the Case presentation section, the phrase "no past medical history" is repeated in the first and second paragraph, and I recommend omitting one of them to avoid repetition.

- In the Discussion section, I think it is out of context to mention the encephalopathy case in the fourth paragraph, or the paragraph can be improved with additional references as there are numerous case reports so far about diverse neurologic manifestations following COVID-19 infection.  

The author presented with an intriguing cases for sure, but I think the manuscript needs a major revision.

Are enough details provided of any physical examination and diagnostic tests, treatment given and outcomes?

Partly

Is the case presented with sufficient detail to be useful for other practitioners?

Partly

Is sufficient discussion included of the importance of the findings and their relevance to future understanding of disease processes, diagnosis or treatment?

Partly

Is the background of the case’s history and progression described in sufficient detail?

Partly

Reviewer Expertise:

neuromuscular diseases

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

F1000Res. 2024 Jun 24.
Amro Abdelrahman

Dear reviewer 

Thanks for taking time and review our article.

- The diagnosis of Bell's palsy is primarily clinical and typically idiopathic. Our diagnosis was based on the acute presentation of classical symptoms, alongside a recent history of upper respiratory infection. According to local protocols, additional investigations such as nerve conduction studies, MRI, or CT are not routinely indicated unless systemic manifestations, recurrent symptoms, or other nerve involvement are present. Further investigations may be warranted in cases with atypical features.

- I agree with you we're not 100% sure about COVID-19 being  the etiology in this case. I think changing the sentence to "A diagnosis of Bell's palsy potenially related to COVID-19 infection was made" would be suffecient.

- The introduction section, a new sentence with a reference will be added for clarification "The relationship between COVID-19 and neurological complications, including facial palsy, is complex and has been the subject of ongoing research. While some cases report facial nerve paralysis occurring within a week of viral symptom onset, there is variability in the reported timeframes."

- We just highlighted briefly some of the poor prognostic factors for the healthcare providers to give extra attention and close follow up for those with the mentioned poor prognostic factors. We believe (prognostic factors in bells palsy related to COVID-19) is a big topic to be included in a case report and need a different paper to extensively go through it. 

- Past medical history will be deleted in the second paragraph

- The sentence will be rephrased to "Various types of neurological manifestations of COVID-19 infection have been reported."  with a new referance

Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Data Citations

    1. Abdelrahman A: Case Report: Bell’s palsy: a neurological manifestation of COVID-19 infection.[Dataset]. Zenodo. 2023. 10.5281/zenodo.8359632 [DOI] [PMC free article] [PubMed]

    Data Availability Statement

    Underlying data

    All data underlying the results are available as part of the article and no additional source data are required.

    Reporting guidelines

    Zenodo: CARE checklist for “Case Report: Bell’s palsy: a neurological manifestation of COVID-19 infection”. https://doi.org/10.5281/zenodo.8359632. 15

    Data are available under the terms of the Creative Commons Attribution 4.0 International license (CC-BY 4.0).


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