Modified Berlin Score for predicting sleep apnea in patients with acute ischemic stroke

Sleep-disorder breathing is common among ischemic stroke patients. It associated with increasing risk of stroke and poor functional outcome after stroke. Polysomnography (PSG) is the diagnostic standard but the application for acute stroke patients is limited. The Berlin Questionnaire (BQ) is a tool used for screen obstructive sleep apnea in general population, however, the diagnostic accuracy in acute ischemic stroke patients is inconsistent.

The study aims to explore the accuracy of Berlin Questionnaire (BQ) for detecting the sleep apnea for acute ischemic stroke patients, using home-based sleep apnea testing as a reference. We compare the accuracy between BQ and a modified BQ.

We conducted a prospective observational study between March 2023 and February 2025 at a teaching hospital in central Taiwan. Patients aged 20-85 years with MRI-confirmed acute ischemic stroke admitted within 48 h of onset were included. Each participant completed the Berlin Questionnaire and underwent home-based sleep apnea testing (Alice NightOne, Philips Respironics). Sleep apnea severity was defined by the respiratory event index (REI). The accuracy of BQ and mBQ in predicting moderate-to-severe sleep apnea (REI ≥ 15) was assessed using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Forty-six patients completed both assessments. Twenty-one patients (45.7%) had no or mild sleep apnea (REI < 15), and 25 (54.3%) had moderate-to-severe sleep apnea (REI ≥ 15). Alcohol use and higher body mass index (BMI) were significantly associated with moderate-to-severe apnea (p = 0.01 for both). The BQ demonstrated a sensitivity of 45.8%, specificity of 72.7%, PPV of 64.7%, and NPV of 55.2% for predicting moderate-to-severe sleep apnea. The mBQ improved performance to a sensitivity of 54.1%, specificity of 72.7%, PPV of 68.4%, and NPV of 59.3%. Patients with moderate-to-severe apnea exhibited significantly lower minimum oxygen saturation compared with those with no or mild apnea (p = 0.03).

The accuracy of the Berlin Questionnaire for detecting sleep apnea in acute ischemic stroke is moderate but improves with modification of BMI weighting. Moderate-to-severe apnea is associated with lower oxygen saturation, highlighting the importance of early screening and targeted management in stroke units. Larger, multicenter studies are warranted to validate these findings and explore the prognostic implications of nocturnal hypoxemia in stroke recovery.