Residual sleepiness in obstructive sleep apnea: Differential diagnosis, evaluation, and possible causes

There is evidence that patients with obstructive sleep apnea (OSA) can have residual excessive daytime sleepiness (EDS), possibly related to other underlying sleep disorders. Further areas of study concerning patients treated adequately for OSA include looking for a biomarker that can easily measure alertness or sleepiness. Radiological modalities may offer another means of assessing patients with EDS. A modality that can provide data without costing too much is key. Some patients continue to have sleepiness after adequate treatment with continuous positive airway pressure, and until these patients can be better classified, it will be difficult to outline better treatment options.