Brain Perfusion in Patients with Severe Sleep Apnea Syndrome (SAS) before and after n-CPAP-Therapy

The aim of the study was to evaluate the therapeutic potential of nocturnal transnasal continuous positive airway pressure breathing (n-CPAP-therapy) with respect to regional cerebral blood flow. 30 patients with severe sleep apnea syndrome (SAS) underwent daytime Tc-99m ECD SPET before and after 6 month n-CPAP-therapy and brain CT (n = 25) to evaluate atrophy. SPET data were analysed visually by 3 experts: Perfusion deficits were mainly located in frontal and temporal lobes. Frontal (p< 0.01) and temporal (p< 0.05) activity significantly increased after therapy. In 10 patients with brain atrophy activity did not change significantly, what probably reflects morphological changes induced by hypoxemia and/or sleep fragmentation.