Spontaneous yawning in patients with multiple sclerosis: A polygraphic study

Area of Science:

• Neurology
• Neuroscience
• Sleep Medicine

Background:

• Multiple sclerosis (MS) is associated with sleep disturbances and repetitive yawning.
• Yawning and swallowing mechanisms may involve brainstem networks, making MS patients a relevant group for study.
• Previous research indicates a temporal relationship between yawning and swallowing in healthy adults.

Purpose of the Study:

• To investigate the frequency of spontaneous yawning (SY) and spontaneous swallowing (SS) in MS patients using polygraphic recordings.
• To explore the relationship between yawning, swallowing, and potential brainstem involvement in MS.
• To test the hypothesis that SY is increased in MS patients.

Main Methods:

• Recruited 49 MS patients and 19 healthy controls.
• Utilized a twelve-channel electroencephalography (EEG) device with electromyography (EMG) and a laryngeal sensor.
• Synchronously recorded cardiac rhythm, respiration, and sympathetic skin responses during swallowing, evaluating SY and SS rates.

Main Results:

• MS patients exhibited significantly higher rates of spontaneous yawning compared to controls (p = 0.044).
• Yawning unrelated to spontaneous swallowing was also significantly increased in MS patients (p = 0.047).
• No significant differences were found in swallowing frequency within, before, or after yawning between the groups. Only 37.5% of MS patients with brainstem involvement showed yawning.

Conclusions:

• Polygraphic recording confirms a significant increase in yawning among MS patients.
• Clinical and MRI findings suggest no direct link between brainstem involvement and the origin of increased yawning in MS.
• The preservation of safe swallowing during yawning suggests intact brainstem mechanisms or oropharyngeal reflexes, though precise localization in MS remains challenging due to the disease's relapsing nature.