Sleep Disorders Increase Likelihood of Poor Functional Status in Neurological Populations

Sleep disorder risk was associated with worse functional and disease-specific outcomes in patients with certain neurological and psychiatric disorders, according to findings in a Cleveland Clinic study recently published in Sleep Medicine.

“Sleep is foundational to health and wellness, along with diet and exercise,” says neurologist Nancy Foldvary-Schaefer, DO, a specialist in sleep disorders and epilepsy at Cleveland Clinic. “You need all three for every cell in your body to get rejuvenated, restored and function optimally.”

While the importance of sleep is common knowledge among physicians, Dr. Foldvary-Schaefer says researchers are now beginning to better understand the mechanistic underpinnings between sleep disorder risk and disease severity. This study represents the largest investigation to date assessing the prevalence of obstructive sleep apnea (OSA), insomnia and comorbid OSA and insomnia (COMISA) in a diverse neurological and psychiatric population and the relationship of sleep screenings with disease-specific severity.

Sleep assessments are key

The study included data collected on 6,224 patients in five specialized centers at Cleveland Clinic Neurological Institute – Brain Tumor, Movement Disorders, Cerebrovascular, Epilepsy and Psychiatric Centers. All patients presenting at these centers complete sleep screening questionnaires along with disease-specific instruments as part of routine clinical care.

The researchers extracted demographic and clinical comorbidity data from electronic health records. Patient-entered data were collected using Cleveland Clinic’s Knowledge Program, an electronic platform for systematic collection of patient-reported outcomes administered on tablets or through the EHR patient portal.

Three metrics were used to assess sleep:

• Average reported sleep time
• The STOP instrument, which notes snoring, feeling tired or sleepy during the day, observed apneas and high blood pressure
• The Insomnia Severity Index, a seven-item instrument assessing the severity of nighttime and daytime components of insomnia symptoms

“Prior to data collection, we already knew that patients with some neurological conditions have higher risk of sleep disorders. For example, sleep apnea and insomnia are particularly prevalent in people with epilepsy,” says Dr. Foldvary-Schaefer. “But we had a unique opportunity to leverage the huge patient-entered data system at Cleveland Clinic and expand our observations to some other areas in neurology and neurosurgery.”

Insight into high-risk COMISA

The study revealed that across the population of people with diverse neurological and psychiatric conditions, approximately a third met criteria for high-risk OSA, a quarter met criteria for insomnia and nearly 12% met criteria for COMISA.

In addition, the researchers examined the relationship between these findings and disease-specific outcomes.

“Smaller studies have documented the prevalence of obstructive sleep apnea and insomnia in conditions such as brain tumor, movement disorders, stroke and epilepsy,” says Dr. Foldvary-Schaefer. “Our findings provide a more comprehensive view, particularly highlighting the heightened prevalence and associated disease-related severity and the prevalence of high-risk COMISA, previously not reported.”

An appeal for large-scale screening

Dr. Foldvary-Schaefer hopes the study helps raise awareness of the high prevalence of common sleep disorders and the importance of screening patients for them.

“It’s a wakeup call to neurological caregivers. Don’t forget about the importance of sleep and the value of sleep disorder screening,” she says. “We have an opportunity to treat sleep disorders, make people feel better, improve their quality of life and perhaps modulate their underlying neurological condition.”

Cleveland Clinic's Sleep app screening tool provides another way for patients and clinicians to keep sleep health issues on the front burner.