Is Sleep the Next Frontier in Movement Science?

Abstract

Lack of sleep is a major health concern in the United States. Poor sleep is associated with lower quality of life and a host of negative health outcomes, including increased mortality.1–4 Sleep disorders are more common in people with neurologic disorder than in the general population. Sleep disordered breathing (SDB) is a risk factor for stroke and leads to poorer functional recovery in people with stroke.5 SDB is common in people with spinal cord injury (SCI), and over 50% of people with SCI report symptoms of insomnia.6 Sleep disorders such as restless leg syndrome (RLS), rapid eye movement sleep behavior disorder, and SDB are common nonmotor symptoms in people with Parkinson disease (PD),7 and people with multiple sclerosis (MS) also report sleep difficulties.8 Physical therapists are uniquely suited to support patients with neurologic disorders who may have sleep difficulties. There are a variety of screening tools that can be used to identify potential sleep disorders. These include the Insomnia Severity Index,9 the STOP-Bang questionnaire for sleep apnea,10 Cambridge Hopkins Restless Leg Syndrome questionnaire,11 and the Epworth Sleepiness Scale.12 Scores on these screening tools taken during an initial examination can guide a referral to a sleep specialist. Importantly for physical therapists, exercise and activity appear to improve sleep quality, apnea hypopnea index, and subjective sleep quality in neurologically intact people.13,14 Although these findings have not been definitively confirmed in people with neurologic disorders, there is preliminary evidence that exercise and activity can improve sleep in people with PD,15 SCI,16 and MS.17 Physical therapy interventions may be having a positive impact on our patients' health that we are not aware of. Research studies examining the impact of exercise and activity in people with neurologic disorders should also consider sleep because it may play a role as a mediator or moderator. Because of the broad impact of activity and sleep on health and quality of life, it is important that we gain a better understanding of the complex relationship between the two. Although there are still many unknowns about how activity and sleep interact, the growing body of research indicates that neurologic physical therapists can play an important role in supporting sleep in our patients.