The latest Paper of the Month from The Journal of Laryngology & Otology is “A rise in facial nerve palsies during the coronavirus disease 2019 pandemic“, by M. Zammit, A. Markey and C. Webb

Throughout the COVID-19 pandemic, a number of multi-organ and neurological complications have been cited by numerous medical centres. During my clinical experience in the Ear, Nose and Throat emergency clinics, our clinical team were alarmed at the high rates of spontaneous lower motor neurone facial nerve (VIIth) palsy referrals received. 

VIIth palsies are thought to be a viral-induced inflammatory reaction, although the exact mechanisms remain uncertain. A course of steroids is the recommended treatment, with a good prognosis.

From a literature search, we did note two case reports of peripheral nerve and potential facial nerve palsies secondary to the infamous Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This led us to perform a retrospective review of VIIth palsy patients encountered over a six-month period.

What did we find?

30 from the 852 patients seen in clinic suffered from VIIth palsies in the six-month period from January to June 2020. This is more than double the number of patients reviewed in the same six-month period in 2019 (14 from 1081 patients).

25 patients attended their follow-up appointment. 72% (18/25) showed complete resolution of their symptoms, whilst 24% (6/25) of patients improved. The remaining 3 patients were booked in for further follow-up appointments, with no symptom improvement.

SARS-CoV-2 testing was performed in 17 patients, with 2 (6%) yielding a positive result. We further compared the COVID-19 incidence in our cohort with that of the catchment area of the NHS hospital trust (2412 recorded cases in the 498,042 population of Liverpool). This showed a significant difference between (6% vs. 0.5%).

What does this imply?

It is difficult to conclude with certainty that COVID-19 is the reason behind this steep incline in VIIth cases, due to our small sample size. Whilst only 57% (17/30) accepted to have SARS-CoV-2 testing, 12% (2/17) were positive, which may be an under-evaluation had the rest of the cohort agreed to testing.

A number of mechanisms have been put forward to explain COVID-19’s involvement. Indirect nerve insult through activation of enzymes triggered by the body’s immune system and direct invasion with resulting nerve damage inflicted by the virus being two explanations postulated by the medical community.

One study also showed a link between raised anxiety levels and VIIth palsy, with our suspect also potentially contributing in this aspect.

What has happened since then?

Further case reports and series have been published since, further raising suspicions COVID-19 being the culprit behind increased rates of VIIth palsy. A prospective study of 41 patients by Islamoglu et al. in 2021 re-affirmed our findings, with an increased prevalence rate of SARS-CoV-2 in VIIth palsy group when compared to their control groups.

With COVID-19 being a main suspect behind the rise in VIIth palsies, we do urge clinicians to be wary of this being one of the presentations of a SARS-CoV-2 infection.

The paper A rise in facial nerve palsies during the coronavirus disease 2019 pandemic“, by M. Zammit, A. Markey and C. Webb, published in The Journal of Laryngology and Otology, is available Open Access.