The Science of Sleep Medicine

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LEXINGTON According to the Centers for Disease Control and Prevention (CDC), most adults need between seven and nine hours of sleep each night. However, only two-thirds of adults in the U. S. actually achieve this, meaning there is one-third of the U.S. adult population that is not getting enough sleep.

“When a patient suffers from insufficient sleep, many problems can occur. Insufficient sleep has been linked to the onset of chronic illnesses including diabetes, hypertension, obesity, and depression, as well as an increase in the likelihood of motor vehicle crashes and machinery-related accidents,” says Craig A. Knox, MD, a neurologist with Lexington Clinic who also serves as a physician with Lexington Clinic’s Sleep Center. “Insufficient sleep may also lead to a decline in the quality of life, reduced work productivity, and increased mortality rate.”

Knox is one of three physicians at the Lexington Clinic Sleep Center, along with Wayne B. Colin, MD, and John F. Dineen, MD. Together, the three physicians provide a comprehensive approach to diagnosing and treating sleep disorders using their expertise in otolaryngology, pulmonology, and neurology. Services and procedures offered include:

► Overnight sleep studies
► At-home sleep studies
► Professional mask fit and instruction
► CPAP titration studies
► CPAP instruction and maintenance
► Durable medical equipment supplies
► Follow-up care for CPAP
► Multiple sleep latency test
► Maintenance of wakefulness test

While the Lexington Clinic Sleep Center treats a wide-range of sleep disorders, the most common condition seen at the sleep clinic is obstructive sleep apnea (OSA). This condition, which occurs mildly in one in five adults, and severely in one in 15, occurs when the airway of a patient becomes blocked during sleep due to relaxation of the throat muscles and tongue. When the airway is blocked, the patient will cease breathing for short periods of time (10 seconds or more) during sleep. This is called an apnea.

“When an apnea occurs, oxygen levels in the patient’s blood may drop, which may result in poor oxygen supply to the brain and heart, increasing the risk of stroke and heart attack,” says Knox. “If left untreated, sleep apnea may also result in poor memory, emotional problems, decreased cognitive functioning, and increased cardiovascular disease.”

“OSA is very much associated with high blood pressure, diabetes, coronary artery disease, irregular heart rhythms, heart failure, stroke, and shortened lifespan,” adds Colin, who is certified by the American Board of Otolaryngology in head and neck surgery, as well as sleep medicine. “Most, if not all, of these conditions seem to be made easier to treat by resolving the OSA.”

OSA is characterized by loud snoring; excessive daytime sleepiness; observed episodes of breathing cessation during sleep; abrupt awakenings with shortness of breath; awaking with dry mouth or sore throat; and morning headaches. To accurately diagnose OSA, a polysomnogram, commonly called a sleep study, is conducted. At the Lexington Clinic Sleep Center, these sleep studies can either be performed in a patient’s home or at the facility.

“During a sleep study, a patient’s efforts at breathing, oxygen levels, and heart rhythms are measured,” says Dineen, a board-certified physician with Lexington Clinic’s Pulmonary department. “Additionally, an EEG is performed to give insight into the patient’s sleep architecture. Normal sleep architecture is seen as characteristic EEG waveforms and durations at the different levels of sleep. But with OSA, the normal EEG architecture is altered, and the deepest and most restful levels of sleep are minimized or gone completely.”

Once diagnosed, OSA can be treated in a variety of ways, both surgical and non-surgical. With very mild sleep apnea, weight loss or a dental appliance can be considered. The most common treatment is through the use of a continuous positive airway pressure machine, or CPAP. With CPAP, air pressure is administered by a mask. That air pressure provides support of the airway so as to prevent the airway’s collapse.

“While a CPAP machine offers relief to OSA patients when worn, it is not considered a cure. Indeed, if at any time a patient does not sleep with the machine, the apneas will still occur. Also, some patients don’t tolerate CPAP. To successfully cure a patient of OSA, surgical treatment is needed,” says Colin.

Surgical options performed at Lexington Clinic to relieve a patient of OSA are often staged and commonly include:

► Nasal, septal, and adenoid surgery (including turbinate reduction)
► Uvulo-palato-pharyngoplasty (UPPP) and tonsillectomy
► Genio-glossus advancement, tongue suspension, and base of tongue reduction
► Hyoid suspension
► Maxillo-mandibular advancement
► Tracheotomy

The type of surgical treatment received is designed specifically to meet the patient’s problem, as OSA blockages do not always occur in the same locations. After diagnosis of OSA and trial of CPAP, a consultation with the surgeon can be performed, which allows for a personal treatment plan to be developed.

“The unique thing about Lexington Clinic’s approach to treating not only OSA, but also sleep disorders in general, is that we take a multi-specialty comprehensive approach to the diagnosis and treatment,” says Dineen. “Through the combined expertise from physicians representing otolaryngology, pulmonary, and neurology specialties, we can more accurately diagnose a patient’s disorder and provide a treatment option that is best for them.”