Sleep-related laryngospasm is a rare sleep condition that refers to episodic, abrupt awakenings from sleep caused by breathing difficulties associated with feelings of suffocation, fear, coughing, and tachycardia. The American Academy of Sleep Medicine’s Third International Classification of Sleep Disorders (ICSD-3) included sleep-related laryngospasm among the sleep-related medical and neurologic disorders in the Appendix A. Though the literature is still mainly based on case series, there is now evidence that the disorder’s prompt recognition and treatment is vital for the patient’s well-being due to its significant impact on sleep. In this article, the authors elaborate on the broad differential diagnosis that has to be considered. Furthermore, the authors shed light on the pathogenesis, complications, and various treatment options available for this intriguing disorder.
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• Sleep-related laryngospasm is a rare condition related to episodic awakenings from sleep, associated with breathing difficulties and a feeling of suffocation.
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• Characteristically, patients describe sudden awakenings from sleep due to feelings of acute suffocation, accompanied by coughing, intense fear, airway obstruction, tachycardia, and stridor. This, in turn, resolves within a few minutes, and breathing returns to normal. Such attacks are traumatic experiences, and patients who suffer frequent attacks are afraid to go to sleep.
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• Sleep-related laryngospasm can be primary or secondary. To give a correct diagnosis it is necessary to collect a detailed history and perform a neurologic and otolaryngologic examination eventually including fibroscopy. Video-polysomnographic recording represents the ideal diagnostic tool in most cases.
Historical note and terminology
Laryngospasm is defined as a sudden, prolonged, forceful apposition of the vocal cords, and it is believed to be the result of a laryngeal reflex response to noxious stimuli. Sleep-related laryngospasm is a clinical condition characterized by episodic, abrupt awakenings from sleep accompanied by a sense of suffocation and followed by stridor that usually evolves to normal breathing. Little has been published on spontaneous laryngospasm during sleep and its devastating effects on sleep quality and patients’ overall quality of life. In 1977, Chodosh reported the first case of gastroesophageal-pharyngeal reflux-induced laryngospasm (08). The first case series was published in 1995, and the term “sleep-related laryngospasm” was designated to describe this condition (01). In 1999, Morrison and colleagues described a distinct clinical entity under the term “the irritable larynx” characterized by dysphonia, episodic laryngospasm, globus and/or cough. The irritable larynx syndrome is hypothesized to arise from repeated exposure to noxious stimuli, such as gastroesophageal reflux, viral illness, or emotional or postural muscle misuse. The authors proposed a hypothesis on neural plastic change to brainstem control networks. According to this theory, the controlling neurons are held in a “spasm-ready” state, and symptoms may be triggered by various stimuli (33).
In the Third International Classification of Sleep Disorders, sleep-related laryngospasm is classified among the sleep-related medical and neurologic disorders in the Appendix A (03).