Background and aims
COVID-19 is a single RNA virus that enters the host cells after binding to the Angiotensin-converting enzyme 2 (ACE2). The symptomatic picture of SARS-CoV-2 is dominated by respiratory disease. However, the spread of the virus, is not circumscribed considering that ACE2 receptor expression is also detected in other tissues, including the CNS. Neurological impairment is more likely in patients with more severe infection, and the most frequently encountered neurological pathologies were acute cerebrovascular disease, impaired consciousness, and impaired taste and sense of smell. Painful neuralgia was less frequent. The aim of our study is to evaluate the possible correlation between COVID-19 infection and trigeminal neuralgia.
From November 2020 to March 2021, 10 cases of trigeminal neuralgia arising after COVID-19 infection were observed. 7 women and 3 men aged 30–55 years with mild-to-moderate infection that did not required hospitalization. Painful symptoms mainly involved the II branch of the V cranial nerve. All patients had brain magnetic resonance imaging (MRI), blink reflex, and VAS pain scale, performed.
Neuroradiological and neurophysiological investigations showed no pathological data, while pain assessment with VAS showed values between 6 and 8. All patients underwent medical therapy with CBZ.
The loss or reduction of taste and/or smell could suggest that the virus reaches the CNS through the olfactory nerve, localizing in the brainstem. This could also explain the involvement of other cranial nerves.