HABITUAL SNORERS AND SLEEP APNOICS HAVE ABNORMAL VASCULAR REACTIONS OF THE SOFT PALATAL MUCOSA ON AFFERENT NERVE-STIMULATION

A local disturbance in the afferent nerves involved in the reflexogeni c dilation of the upper airways (UAs) could contribute to the increase d collapsibility seen in patients with obstructive sleep apnea (OSA). Laser Doppler perfusion monitoring, combined with electrical stimulati on, is a method for investigating the afferent nerve regulation of the microcirculation. It was used in the mucosa of the soft palate in 35 patients with various degrees of UA obstruction and in 13 control subj ects, all nonsmoking men. In a majority of snorers and patients with m ild OSA, stimulation induced an exaggerated vasodilation, compared wit h controls. In contrast, in patients with severe OSA, the vasodilation was significantly reduced, compared with controls. These signs of dis turbances in the microcirculation support the hypothesis of a local pr ogressive afferent nerve lesion in heavy snorers with or without OSA.