Sleep-disordered breathing: Effects on brain structure and function

• Injury to neural structures and axons accompanies sleep-disordered breathing.
• Autonomic and major neurotransmitters systems are especially affected.
• Injury occurs as water diffusion, myelin and axonal changes, and tissue loss.
• Time- or amplitude-distorted fMRI signals emerge to ventilatory/autonomic challenges.
• Sympathetic, breathing, memory, mood, and cognitive deficits result from the injuries.

Sleep-disordered breathing is accompanied by neural injury that affects a wide range of physiological systems which include processes for sensing chemoreception and airflow, driving respiratory musculature, timing circuitry for coordination of breathing patterning, and integration of blood pressure mechanisms with respiration. The damage also occurs in regions mediating emotion and mood, as well as areas regulating memory and cognitive functioning, and appears in structures that serve significant glycemic control processes. The injured structures include brain areas involved in hormone release and action of major neurotransmitters, including those playing a role in depression. The injury is reflected in a range of structural magnetic resonance procedures, and also appears as functional distortions of evoked activity in brain areas mediating vital autonomic and breathing functions. The damage is preferentially unilateral, and includes axonal projections; the asymmetry of the injury poses unique concerns for sympathetic discharge and potential consequences for arrhythmia. Sleep-disordered breathing should be viewed as a condition that includes central nervous system injury and impaired function; the processes underlying injury remain unclear.