WHY YOU CAN’T STAY AWAKE: THE PHYSICAL CAUSES OF SLEEP APNEA – CAUSES OF APENIA ARISING
There are a number of physical problems that can also provide hints about the causes of a patient’s OSA. As you might expect, if you are overweight you are more prone to airway obstruction. Your respiratory muscles may be unable to overcome the additional pressure from body weight in order to contract and keep the airway open. Furthermore, accumulations of fatty tissue in this region of the body may act to block the passage of air. Sleep apnea is especially common in children with large tonsils and adenoids. If obesity is also present, these children are known by the rather unflattering sobriquet “chubby puffers.”
Apnea can also arise from an excessively thick palate, an enlarged uvula or thyroid gland, or such deformities as retro-gnathia (receding jaw), micrognathia (small jaw), or bony abnormalities of the upper airway, including a short neck, which can position the tongue too close to the back of the pharyngeal wall and thus reduce airflow. Conditions such as amyloidosis (accumulation of starchy substance in tissue) or myxedema (swelling associated with hypothyroidism) can result in an enlarged tongue, causing obstructed breathing. Hypothyroidism blunts the respiratory drive and may also contribute to obesity. Sometimes lesions in the nose can be a factor in collapse of the airways, and polyps or tumors in the larynx can also lead to apnea. Acromegaly, an oversecretion of growth hormone that causes enlargements in skeletal extremities, including the jaw and nose, can do so as well.
On more than one occasion I’ve seen a patient whose dentures were to blame: badly fitting false teeth can cause the muscles of the mouth to strain to keep them in place. Removing the dentures at night can lead to unusual relaxation of the muscles, in turn causing the airways in the mouth and throat to collapse to some degree.
Sometimes, in rare cases, the cause is more serious—pharyngeal cancer, for example, or a neurological disease such as poliomyelitis, myasthenia gravis (a disease that can produce fatigue in the muscle systems of the throat and neck), or amyotrophic lateral sclerosis (an often fatal degeneration of the brain stem and spinal cord). In other cases, spinal surgery, brain stem infarction or growth, pulmonary disease, or cardiac disorders may be responsible.