Oropharyngeal Exercises and Post-Stroke Obstructive Sleep Apnea

BACKGROUND Obstructive sleep apnea (OSA) is characterized by recurrent obstruction of the upper airway during sleep due to intermittent loss of pharyngeal dilator muscle tone. OSA is both a risk factor for stroke, as well as a common post-stroke co-morbidity with approximately 72% of patients with stroke or transient ischemic attack (TIA) having OSA. Post-stroke OSA is linked to post-stroke, fatigue, which is a top research priority for stroke patients. Moreover, post-stroke OSA is associated with greater mortality, a higher risk of recurrent stroke, poorer cognition and lower functional status. In addition, stroke patients with OSA spend significantly longer times in rehabilitation and in acute care hospitals. Since OSA has a significant impact on the health of stroke patients, it is imperative that effective treatments are used to assist patients. Continuous positive airway pressure (CPAP) is the gold standard treatment for patients with moderate to severe OSA. However, despite having been demonstrated to improve post-stroke cognition, motor and functional outcomes,and overall quality of life, rates of CPAP adherence are low. Reasons for poor post-stroke CPAP adherence are multi-factorial and often not easily modifiable. Overall, there is a major clinical need to develop an alternative effective and well-tolerated treatment for OSA.

Oro-pharyngeal exercises (O-PEs) are commonly used by speech-language pathologists to improve oro-motor strength and range of motion and serve as a promising alternative approach to treat OSA. For example, in a randomized controlled trial in which patients with moderate OSA underwent 3 months of daily exercises focusing on strengthening oro-pharyngeal musculature, OSA severity and symptoms were demonstrated to be significantly reduced compared to sham exercises.Similarly, use of the didgeridoo, a wind instrument that strengthens muscles of the upper airway, has also been demonstrated to reduce OSA severity.

METHODS Research Question: Is a randomized controlled trial (RCT) of an O-PE regimen in post-stroke OSA feasible?

Primary Objective: To examine whether an RCT of an O-PE regimen is feasible in stroke patients with OSA who are unable to tolerate CPAP. (i) The O-PE regimen will be considered feasible if >80% of enrolled patients complete >80% of the study exercises. (ii) We will also track the monthly number of eligible vs. recruited patients from Dr. Boulos' stroke and sleep disorders clinic. Hypothesis: An RCT of an O-PE regimen in post-stroke OSA will be feasible in that >80% of enrolled patients will complete >80% of the study exercises.

Secondary Objectives: To explore whether an O-PE regimen, compared to sham activities, might be effective in (i) improving various objective sleep metrics (i.e. OSA severity and nocturnal oxygen saturation), (ii) improving various measures of oropharyngeal physiology and function (i.e. oro-pharyngeal deficits and dysarthria, tongue/lip/jaw weakness, and oro-facial kinematics), and (iii) enhancing self-reported sleep-related symptoms. Hypothesis: Compared to the sham activities, O-PEs will positively influence the outcomes noted above.

Inclusion criteria

• Imaging-confirmed stroke or stroke specialist-diagnosed transient ischemic attack (TIA)
• Prior diagnosis of OSA by a physician at any time in the past.
• Unable to tolerate CPAP after a 2-week trial of CPAP

Exclusion criteria

• BMI > 40 kg/m2
• The presence of conditions known to compromise the accuracy of portable sleep monitoring, such as moderate to severe pulmonary disease or congestive heart failure.
• Oxygen therapy (e.g. nasal prongs), a nasogastric tube, or other medical device that would interfere with the placement of the home sleep apnea test
• Cranial malformations/nasal obstruction
• Significant depressive symptoms
• Regular use of hypnotic medications
• Other neuromuscular diseases or conditions affecting oropharyngeal muscles
• Montreal Cognitive Assessment (MoCA) < 18
• Aphasia
• Oral or apraxia of speech