Sleep-Disordered Breathing: Imposing Challenges in Spinal Cord Injury

Patients with spinal cord injury or disease (SCI/D) are 3 to 4 times more likely to have sleep disordered breathing (SDB) than individuals  in the general population.¹ The prevalence of SDB — both central and obstructive sleep apnea — ranges from 27% to 82% in patients with subacute and chronic SCI/D.¹

The Why and How of SDB in SCI

The type of spinal cord injury affects the prevalence of SDB; patients with quadriplegia are more likely to have SDB than patients with paraplegia.¹ Likewise, patients with cervical vs thoracic SCI have a higher prevalence of SDB (93% vs 55%, respectively).¹ Even in patients with nontraumatic SCI, such as multiple sclerosis, rheumatoid arthritis, and spinal muscular atrophy, SDB prevalence is higher than in the general population.¹

The sleep fragmentation and intermittent hypoxemia of SDB have shown deleterious effects on cardiovascular outcomes, especially nocturnal hypertension and increased mortality.¹ In patients with quadriplegia, SDB is associated with neuropsychological dysfunction such as impaired information processing, immediate recall, and attention.²

During sleep, the respiratory system works harder due to pharyngeal narrowing and the collapsibility of the upper airway.¹ Adding to the difficulty of nighttime breathing are neuromuscular weakness, abnormal chest wall mechanics, reduced lung volumes, and central nervous system suppressants.¹

Even the Best Treatments Are Not Optimal

Continuous positive airway pressure (CPAP) therapy is considered first-line therapy in patients with SCI/D who have SDB.¹ However, because of the inconvenience, limited upper extremity mobility, and nasal congestion, CPAP therapy is not always practical and is often discontinued.¹

To improve treatment in SDB, clinicians need to provide better facilities for diagnosing the type of SDB in specialized sleep centers that can accommodate patients with SCI/D, including wheelchair accessibility, lifts, and well-trained staff.¹ Future therapies could target nerve stimulation of the laryngeal and oropharyngeal muscles in patients with obstructive SDB.¹

The Consequences of SDB

Schembri and colleagues sought to determine whether sleep apnea leads to neurocognitive dysfunction and daytime sleepiness in patients with acute-onset cervical SCI.² In the study, 104 patients (mean age, 45.6 years; 90 men) were tested for attention, information processing, memory, executive function, learning, mood, and quality of life. Although severe sleep apnea did not affect memory, it did result in worse outcomes in attention, information processing, and immediate recall.²