Figure 2.

(A) Obstructive sleep apnea (OSA): The episodic breathing session and repeated obstructions in the upper airway worsen nocturnal respiration and sleep. OSA produces irregular respiratory patterns, hypoventilation, nocturnal worsened respiration, and oxidative stress due to the resaturation and desaturation of oxygen levels, and produces damage to dopaminergic neurons. (B) Restless legs syndrome (RLS): Hypo-functioning of dopamine signaling due to reduced dopamine subtype 2 receptor (D2R) expression in the CNS. Reduced peripheral blood flow causes peripheral hypoxia, which leads to urges to move legs and causes defects in neurological sensorimotor functions. (Figure created using BioRender.com; accessed on 27 June 2023).