Rhinitis and sleep disorders: The trigeminocardiac reflex link?

Area of Science:

• Nasal pathophysiology
• Sleep medicine
• Neuroimmunology

Background:

• Rhinitis, both allergic and non-allergic, involves nasal inflammation and is linked to various sleep disorders.
• Current understanding of sleep disorder mechanisms in rhinitis, often attributed to nasal congestion and inflammatory mediators, remains incomplete.
• The trigeminocardiac reflex (TCR), involving the trigeminal nerve, has been associated with sleep disorders like sleep apnea and bruxism.

Purpose of the Study:

• To explore the potential role of the trigeminocardiac reflex (TCR) as a mechanistic link between rhinitis and sleep disorders.
• To investigate how nasal inflammation in rhinitis might influence TCR occurrence and contribute to sleep disturbances.

Main Methods:

• Review of existing literature on rhinitis, sleep disorders, and the trigeminocardiac reflex.
• Analysis of the physiological interplay between nasal trigeminal afferents, inflammation, autonomic nervous system activity, and TCR.
• Hypothesizing the role of neuronal hyper-responsiveness in rhinitis-induced TCR.

Main Results:

• Nasal inflammation in rhinitis can lead to hyper-responsive trigeminal afferents, potentially increasing TCR frequency.
• Both rhinitis and TCR involve autonomic nervous system dysregulation, with parasympathetic overactivity and sympathetic inhibition noted in TCR.
• The trigeminal nerve stimulation, including via nasal mucosa, can trigger TCR, which manifests with bradycardia, hypotension, and apnea.

Conclusions:

• The trigeminocardiac reflex (TCR) is hypothesized to be a key link connecting rhinitis and sleep disorders.
• Further research into TCR in the context of rhinitis is warranted to elucidate the pathophysiology of associated sleep disturbances.
• Understanding this link may lead to novel therapeutic strategies for sleep disorders in patients with rhinitis.