There are two main types of sleep apnea. “Central Sleep Apnea” appears to be related to a malfunction of the brain’s normal signal to breathe, therefore cannot be treated by dental sleep appliances. It is less common than “Obstructive sleep apnea” which may represent cessation of breathing due to mechanical blockage of the airway. Prompt and proper diagnosis is an important first step to treating any and all forms of sleep apnea. Problems associated with untreated sleep apnea include hypertension, coronary artery disease, myocardial infarction, stroke, psychiatric problems, impotence, cognitive dysfunction, memory loss, and death.
Source: National Institutes of Health