What is your diagnostic approach to patients referred for central sleep apnea on PSG but normal overnight EEG and MRI?

In lab titration study, starting with CPAP (first-line treatment, can work in many cases). If remains, BiPAP-S titration is next (usually same night) with minimum EPAP titrated to prevent apneas and IPAP to prevent hypopneas but care as to avoid too much pressure support and over ventilation. Failur...