Breathing disorders including sleep apnea appear to have a higher prevalence in people after SCI than those without. In general, the studies that examined the prevalence of obstructive sleep apnea were limited by small sample sizes and by an experimental design that lacked an able-bodied control group that could be directly compared to the SCI patients. Both overnight oximetry and full polysomnography were used to diagnose disease. The prevalence rate ranged from 9.1-83% (Short et al. 1992; Burns et al. 2000; Burns et al. 2001; Stockhammer et al. 2002; Berlowitz et al. 2005). Obesity was identified as a risk factor for sleep apnea in most studies. The use of muscle relaxants was identified as a potential risk factor for sleep disordered breathing in some but not all studies (Short et al. 1992; Ayas et al. 2001; Burns et al. 2001; Berlowitz et al. 2005).
Obstructive sleep apnea is very common in patients with SCI; obesity appears to be a consistent risk factor. There are few studies that have assessed the impact of sleep apnea therapy in patients with SCI. In a three person case series, Biering-Sørensen demonstrated successful therapy with CPAP in two patients, and with weight loss in the third. No randomized controlled trials of CPAP have been reported. One study (Burns et al. 2000) demonstrated a low acceptance rate of CPAP (2 of 8 patients) given a trial of therapy. However, two larger studies demonstrated greater rates; Burns et al. (2005) demonstrated a long-term acceptance rate of CPAP of 63% (20/32) in patients offered CPAP therapy, and Stockhammer et al. (2002) reported a long-term rate of 69% (11/16 who accepted a trial). Patients who continued to use CPAP in general reported beneficial effects. No reports concerning the treatment of SCI patients with sleep apnea with a dental appliance or upper airway surgery were identified. There is a paucity of studies that have examined the impact of sleep apnea therapy on health and quality of life outcomes in SCI; this should be a focus of future investigations.
There is level 4 evidence (based on 2 case series and 1 pre-post study) (Stockhammer et al. 2002; Burns et al. 2005; Biering-Sørensen et al. 1995) to support therapies to treat obstructive sleep apnea in people with SCI.
- Patients with SCI have a high prevalence of obstructive sleep apnea, and therapy may improve quality of life and other outcomes. Therefore, we recommend vigilance for suggestive signs and symptoms (e.g., snoring, obesity, witnessed apneas, daytime sleepiness) and further testing in patients with suggestive symptoms/signs (with overnight oximetry or polysomnography).