Responses of spinal trigeminal neurons to noxious stimulation of paranasal cavities - a rat model of rhinosinusitis headache

COVID-19-related headache and sinonasal inflammation: A longitudinal study analysing the role of acute rhinosinusitis and ICHD-3 classification difficulties in SARS-CoV-2 infection

Background

The genesis of headache in coronavirus disease 2019 (COVID-19) is currently unclear and the multitude of disease symptoms often further hinders locating the source of pain. Interestingly, many subjects with COVID-19 have symptoms of acute rhinosinusitis. The relation between nasal symptoms and headache in SARS-CoV-2 infection remains unknown.

Methods

This bi-center longitudinal study evaluated symptoms in consecutive COVID-19 patients in the participating practices. The first assessment was performed during the initial consultation after infection confirmation. That was followed up by a second consultation after a median 9 days.

Results

130 patients were included in the study (80 women, 50 men; mean age 46.9 years). Headache was highly prevalent at the first visit (72%) and significantly associated with acute rhinosinusitis symptoms. The odds ratio for headache in subjects with rhinosinusitis was 3.5. Headache could be attributed to systemic viral infection in 96% and to acute rhinosinusitis in 51% of cases according to 3rd edition of the International Classification of Headache Disorders. Criterium C.3 (exacerbation of headache by pressure applied over paranasal sinuses) and C.4 (ipsilaterality of headache and sinusitis) had low sensitivity in headache attributed to acute rhinosinusitis.

Conclusions

Nasal inflammation is associated with headache in COVID-19, although the pain mechanism lies probably in a systemic reaction to the virus. 3rd edition of the International Classification of Headache Disorders criteria for headache attributed to acute rhinosinusitis need adjusting to the current understanding of acute sinonasal infection.

Activation of the trigeminal system as a likely target of SARS-CoV-2 may contribute to anosmia in COVID-19

Clinical publications show consistently that headache is a common symptom in the coronavirus disease of 2019 (COVID-19). Several studies specifically investigated headache symptomatology and associated features in patients with COVID-19. The headache is frequently debilitating with manifold characters including migraine-like characteristics. Studies suggested that COVID-19 patients with headache vs. those without headache are more likely to have anosmia. We present a pathophysiological hypothesis which may explain this phenomenon, discuss current hypotheses about how the coronavirus SARS-CoV-2 enters the central nervous system and suggest that activation of the trigeminal nerve may contribute to both headache and anosmia in COVID-19.