Definition

     Sleep apnea is a condition characterized by episodes of stopped breathing during sleep. There are three types of Sleep Apnea: central, obstruction, or mixed. Central Sleep Apnea occurs because the respiratory drive in the brain is suppressed, or the muscles and nerves that control respiration are functioning abnormally. Obstructive Sleep Apnea is where the throat-pharynx narrows during sleep and obstructs airflow to the lungs.

Causes

• Central:

1. Metabolic control of the airway is impaired e.g., respiration does not "kick in" when carbon dioxide levels in the blood rise.

2. Respiratory drive center in the brain is not working properly e.g., from a Stroke, heart disease, or lung disease

3. Neurological reflexes (undesirably) inhibit the central respiratory drive in the brain, e.g., esophageal Reflux or aspiration

1. Increased airway muscle tone (so less air gets in)

2. Increased airway lumen tone

3. Decrease upper airway pressure (below atmospheric so upper airways collapse)

4. Obstruction of part of the airway

Symptoms 

     It is important to emphasize that often, the person who has obstructive sleep apnea does not remember the episodes of apnea during the night. The predominant symptoms are usually associated with excessive daytime sleepiness due to poor sleep during the night. Often, family members, especially spouses, witness the periods of apnea. Symptoms that may be observed include:

• Loud snoring

• Periods of not breathing (apnea)

• Awakening not rested in the morning

• Abnormal daytime sleepiness, including falling asleep at inappropriate times

• Morning headaches

• Recent weight gain

• Limited attention

• Memory loss

• Poor judgment

• Personality changes

• Lethargy

     Additional symptoms that may be associated with this disease:

• Hyperactive behavior, especially in children

• High blood pressure

• Automatic behavior (performing actions by rote)

• Leg swelling (if severe)

Screening and Diagnostics

• Sleep study called polysomnography-measures the stages of sleep, ventilation, oxygen saturation, and the heart rate.

• Evaluation by an Ear, Nose, & Throat Specialist may be needed in obstructive Sleep Apnea

Treatment

• Obstructive Sleep Apnea (listed by cause)

• Central Sleep Apnea

Complications 

• Hypertension

• Right-sided heart failure

• Abnormal heart rhythm (arrhythmia)

• Excessive carbon dioxide levels (hypercapnia)

• Sleep deprivation

• Stroke

• Heart disease

Prevention 

     Weight reduction and avoiding alcohol and sedatives may help some individuals. Children with very large adenoids and tonsils may develop obstructive sleep apnea and its associated problems, and should have a tonsillectomy and adenoidectomy.