Neuroimaging to Evaluate for Structural Brain Lesions in Central Sleep Apnea

Diagnostic Rationale

In patients with five or more central sleep apnea episodes per hour, brain MRI should be performed to evaluate for structural lesions affecting respiratory control centers, particularly in the brainstem and cerebellum 1
The presence of significant central sleep apnea warrants investigation for underlying neurological causes, as structural brain lesions can disrupt respiratory control mechanisms 1

Polysomnography must first confirm the diagnosis of CSA by demonstrating central apneas without respiratory effort, an apnea-hypopnea index (AHI) ≥5 events/hour with central events predominating, and absence of rib cage and abdominal movement during apneic episodes 1

Neurological disorders are a recognized cause of CSA, and the following presentations should prompt neuroimaging: history of stroke or transient ischemic attack, suspected neurodegenerative disease, unexplained CSA without heart failure, medication use, or other clear etiology, and presence of other neurological symptoms or signs 1

Before attributing CSA to structural brain lesions, exclude more common etiologies such as heart failure, atrial fibrillation, chronic opioid or sedative use, renal failure, and treatment-emergent CSA from CPAP therapy 1
Do not assume all apneas are obstructive - polysomnography with assessment of respiratory effort is mandatory to distinguish central from obstructive events before pursuing neuroimaging 1
In patients with marked respiratory muscle weakness, true obstructive events may be misscored as "central" on external sensors, requiring esophageal pressure monitoring 2 3

Brain imaging may be deferred initially if CSA occurs in the context of known severe heart failure with typical Cheyne-Stokes respiration pattern, recent initiation or dose increase of opioids or sedatives, or end-stage renal disease on dialysis 1
In these cases, treat the underlying condition first and reassess CSA persistence before pursuing neuroimaging 1