Millions of Indians are plagued by Sleep Disorders. It is a serious public health risk that too many doctors ignore. Half of Sleep Disorders consist of lack of sleep while other half consist of daytime sleepiness or over sleep. Sleep for certain hours is a compulsory physiological event of the brain for proper functioning of the body for remaining hours in 24 hours cycle. In 1953, it was discovered that sleep was actually comprised of two different states: non-rapid eye movement (NREM) and rapid eye movement (REM) Sleep.
Sleep Disorder Medicine is a clinical specialty, which deals with diagnosis and treatment of patients who complain about disturbed nocturnal sleep, excessive daytime sleep and other sleep related problems. The most important clinical symptom in sleep disorder medicine is awareness of sleep related impaired alertness, in other words a complaint of excessive sleepiness. Important sleep disorder are, insomnia, sleep apnea syndrome, narcolepsy and parasomnias.
Sleep apnea is a syndrome that causes people to frequently stop breathing during sleep. As a result they fail to get the oxygen their body needs and restful night’s sleep. Sleep apnea is a serious condition; it can lead to increased risk of heart problem, excessive daytime sleepiness, decreased performance at work, memory loss and greater possibility of accidents. Sleep apnea affects about 3.5 per cent to 5 per cent population between the age group of 40-50 years. the condition is seen primarily in males over 40 years of age. Approximately 70 per cent of these people are obese. Patients often have short and thick neck, usually 17 inches or greater. Sleep apnea is a correctable health problem.
There are three types of sleep apnea encountered in clinical practice.
A. Obstructive Sleep Apnea: It is a most common type of sleep apnea and is caused by upper airway obstruction. The respiratory effort is present but there is no airflow at mouth. The site of obstruction is at the pharynx.
B. Central Sleep Apnea: It is the least common type of sleep apnea. In this there is failure of respiratory Center to send proper signals for breathing. In this type of apnea there is total absence of respiratory efforts and airflow at mouth.
C. Mixed Apnea: It is a combination of obstructive and central apnea.
Obstructive sleep apnea is caused by closure of upper airway anywhere between nasopharynx to hypopharynx. This is combined effect of structural and neuromuscular factor on the patency of upper airway. Main structural factors are