What Is the Prevalence of Sleep Disorders in Neurologic Populations?

LOS ANGELES—About one-third of neurologic patients has a high risk of obstructive sleep apnea (OSA), and approximately one-quarter has significant symptoms of insomnia, according to data presented at the 70th Annual Meeting of the American Academy of Neurology. The presence of insomnia symptoms is associated with worse neurologic status in movement disorders and epilepsy populations, researchers said.

“Given the high prevalence of sleep disorder symptoms, further investigation into the role of sleep therapies on disease-specific outcomes in neurologic populations is warranted,” said Thapanee Somboon, MD, a neurologist at Prasat Neurological Institute in Bangkok, Thailand, and research fellow at the Cleveland Clinic Sleep Disorders Center, and colleagues.

Thapanee Somboon, MD

Analyzing STOP and Insomnia Severity Index Scores

OSA and insomnia are highly prevalent in the general population and may be more common in patients with neurologic conditions. To examine the association between sleep instrument scores and disease-specific outcomes in neurologic populations, Dr. Somboon and colleagues conducted a retrospective analysis of data from 19,052 adult initial visits to the psychiatry, brain tumor, movement disorders, cerebrovascular, and epilepsy centers at the Cleveland Clinic between March 2015 and October 2016.

In all, 7,762 patients had completed the snoring, tiredness, observed apnea, and high blood pressure (STOP) questionnaire, and 8,530 patients had completed the Insomnia Severity Index. A STOP score of 2 or greater predicted a high risk of OSA, and an Insomnia Severity Index score of 15 or greater indicated significant insomnia symptoms.

The crude prevalence of high-risk OSA was 47.9% in the cerebrovascular center, 44.1% in the movement disorders center, 34% in the brain tumor center, 33% in the epilepsy center, 29.8% in the psychiatry center, and 36.7% overall.

The crude prevalence of significant insomnia symptoms was 33.6% in the psychiatry center, 26.1% in the epilepsy center, 20.7% in the brain tumor center, 20% in the movement disorders center, 19.5% in the cerebrovascular center, and 25.5% overall.

Disease-Specific Outcomes

The researchers used regression models to adjust for patients’ age, sex, race, marital status, self-reported sleep duration, income, tobacco use, and comorbid conditions. Multivariate models evaluated the associations between abnormal sleep scores and scores on the Patient Health Questionnaire-9 (PHQ-9; from all centers), Karnofsky Performance Status (from the brain tumor center), Unified Parkinson’s Disease Rating Scale (UPDRS II; from the movement disorders center), modified Rankin Scale (from the cerebrovascular center), and Liverpool Seizure Severity Scale (from the epilepsy center).

Patients with a STOP score of 2 or greater were older, more likely to be male, more likely to be a current or former smoker, had greater PHQ-9 scores, and had more comorbidities.

Patients with Insomnia Severity Index scores of 15 or greater were younger, more likely to be female, more likely to be a current or former smoker, and had a higher prevalence of depression.

OSA and insomnia were significantly associated with PHQ-9 scores. In addition, insomnia symptoms were significantly associated with Liverpool Seizure Severity Scale and UPDRS II scores.

—Jake Remaly