Electrophysiological evidence of subclinical trigeminal dysfunction in patients with COVID-19 and smell impairment: A pilot study.

Autor:	Cosentino G; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.; Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy., Maiorano E; Department of Otolaryngology-Head and Neck Surgery, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy., Todisco M; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.; Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy., Prunetti P; Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy., Antoniazzi E; Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy., Tammam G; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy., Quartesan I; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy., Lettieri S; Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy., De Icco R; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.; Headache Science and Neurorehabilitation Center, IRCCS Mondino Foundation, Pavia, Italy., Corsico AG; Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.; Pneumology Unit, IRCCS San Matteo Hospital Foundation, Pavia, Italy., Benazzo M; Department of Otolaryngology-Head and Neck Surgery, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.; Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy., Pisani A; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.; Movement Disorders Research Center, IRCCS Mondino Foundation, Pavia, Italy., Tassorelli C; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy.; Headache Science and Neurorehabilitation Center, IRCCS Mondino Foundation, Pavia, Italy., Alfonsi E; Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy.
Jazyk:	angličtina
Zdroj:	Frontiers in neurology [Front Neurol] 2022 Oct 14; Vol. 13, pp. 981888. Date of Electronic Publication: 2022 Oct 14 (Print Publication: 2022).
DOI:	10.3389/fneur.2022.981888
Abstrakt:	Background: Smell and taste disturbances are among the most frequent neurological symptoms in patients with COVID-19. A concomitant impairment of the trigeminal nerve has been suggested in subjects with olfactory dysfunction, although it has not been confirmed with objective measurement techniques. In this study, we explored the trigeminal function and its correlations with clinical features in COVID-19 patients with impaired smell perception using electrophysiological testing. Methods: We enrolled 16 consecutive patients with mild COVID-19 and smell impairment and 14 healthy controls (HCs). Olfactory and gustatory symptoms were assessed with self-reported questionnaires. Electrophysiological evaluation of the masseter inhibitory reflex (MIR) and blink reflex (BR) was carried out to test the trigeminal function and its connections within the brainstem. Results: Masseter inhibitory reflex (MIR) analysis revealed higher latency of ipsilateral and contralateral early silent period in patients when compared with HCs. No significant differences between groups were detected as regards the duration of the early and late silent period. However, several patients showed a prolonged duration of the early silent period. BR evaluation disclosed only an increased amplitude of early components in patients. Conclusions: Patients with COVID-19 and smell impairment show a subclinical trigeminal nerve impairment. Trigeminal alterations mainly involve the oligosynaptic pathway, as a result of either direct viral damage or secondary neuroinflammation of the peripheral trigeminal fibers, whereas the polysynaptic ponto-medullary circuits seem to be spared. The prolonged duration of the early silent period and the increased amplitude of early BR response might reflect a compensatory upregulation of the trigeminal function as a consequence of the olfactory dysfunction. Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. (Copyright © 2022 Cosentino, Maiorano, Todisco, Prunetti, Antoniazzi, Tammam, Quartesan, Lettieri, De Icco, Corsico, Benazzo, Pisani, Tassorelli and Alfonsi.)
Databáze:	MEDLINE
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