Sleep Apnea after Stroke

Sleep apnea is quite common after stroke and associated with poor functional outcomes. Research studies have determined that over half (50%–70%) of stroke survivors have sleep apnea (Kotzian et al., 2012). Sleep-related breathing disturbances and sleep-wake disturbances are often neglected in stroke patients. There are two ways of determining if a person has sleep apnea — 1) Subjective evaluation of symptoms by the health care team (which could include the Berlin questionnaire) and 2) Sleep study that includes a polysonogram.

A recent study highly recommended sleep studies for stroke patients because stroke survivors with untreated sleep apnea have poorer functional outcomes.

A Sleep Study

A sleep study is the most accurate test for diagnosing sleep apnea. It records what happens with your breathing while you sleep. There are different kinds of sleep studies. If your doctor suspects you have sleep apnea, he or she may recommend a polysomnogram or a home-based portable monitor.

Most often sleep studies are done at sleep centers or sleep labs. In some cases, doctors will suggest using a portable sleep monitor at home because it is cheaper.

Prevent stroke by treating sleep apnea?

If you have sleep apnea, you may be at higher risk of stroke. A 2010  study of provides pretty compelling evidence that if you have untreated moderate to severe sleep apnea, you have 3 times the risk of stroke (Redline et al., 2010).

Ask your doctor to evaluate if you have sleep apnea.

More information

• National Institutes of Health - Sleep Apnea Diagnosis
• University of Maryland - Sleep Apnea Diagnosis 
• Redline et al., (2010). Obstructive Sleep Apnea–Hypopnea and Incident Stroke The Sleep Heart Health Study. American Journal of  Respiratory Critical  Care Medicine, 182;  269–277. 
• The Berlin Questionaire
• Kotzian ST; Stanek JK; Pinter MM; Grossmann W; Saletu MT (2012). Subjective evaluation of sleep apnea is not sufficient in stroke rehabilitation. Topics In Stroke Rehabilitation Vol. 19 (1), pp. 45-53. 

Objective: Sleep apnea (SA) is common in stroke patients and is associated with poor functional outcome. Therefore, we studied the clinical value of the Berlin Questionnaire (BQ), a subjective screening method to detect stroke patients with SA in a neurorehabilitation care unit, and compared it with respirographic sleep studies. Another aim was to explore the association of SA with functional status in the subacute phase after stroke.

Methods: Sixty-eight stroke patients were subjected to respirographic sleep studies to determine their apnea-hypopnea index (AHI). Subjective evaluation was performed by means of the BQ. Functional outcome was assessed by the Barthel Index (BI). Sensitivity and specificity of the BQ for detecting SA in stroke patients were calculated.

Results: Respirographic sleep studies showed a high prevalence of moderate and severe sleep apnea in 56% of stroke patients. Sensitivity and specificity of the BQ for SA (AHI ≯ 15) were 0.69 and 0.15, respectively. The area under the receiver operating characteristics (ROC) curve for detection of SA was 0.58. The AHI correlated significantly with the BI (r = -0.57, P ≤ .001).

Conclusion: As the BQ demonstrated low diagnostic utility in stroke rehabilitation, screening for SA should not be based solely on clinical interviews. SA is linked to poor functional status in the subacute phase post stroke.

Resources

• American Sleep Apnea Association
• American Academy of Sleep Medicine
• National Sleep Foundation
• National Center on Sleep Disorders Research
• Sleep Education from the American Academy of Sleep Medicine