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Sleep Disorders Center

Phone: (865) 373-1975

What is a Sleep Disorder?

Sleep disorders can affect overall health, and some may be life threatening. In addition to daytime sleepiness and fatigue, certain disorders may cause high blood pressure and serious heart problems. Sufferers often experience more illness, more accidents, reduced job performance, and strained relationships.


Patients may see many of the following during their evaluation and treatment:

Our Certified Sleep Physician, Nurse Practitioner, or PSG/CPAP technicians.

Berta Bergia, MD, DABSM, FAASM

Berta Bergia, MD, DABSM, FAASM became a Diplomate of the American Board of Sleep Medicine in January 2008. She comes to sleep medicine from the field of Neurology with Board Certification in Neurology and Neurophysiology. She did her residencies at the University of Texas at Houston, and Boston University. She did her fellowship training in clinical Neurophysiology and sleep at Emory University of Atlanta Georgia. Dr. Bergia is bilingual; speaking English and Spanish. She is a disability examiner for the State of Tennessee with special training in Independent Medical Exams. She became the Medical Director of Parkwest Sleep Disorders Center in March 2008.

Farrukh Siddiqui, MD, MPH

Farrukh Siddiqui, MD, MPH, sleep medicine specialist, specializes in treating sleep disorders for people of all ages, including conditions such as sleep-disordered breathing, insomnia, hypersomnia, parasomnias and narcolepsy. Dr. Siddiqui is board certified in both sleep medicine and family medicine. He received his medical degree from Northeast Ohio Medical University and a master’s degree in public health from the Harvard School of Public Health. Dr. Siddiqui completed a residency in occupational medicine at Harvard University and a residency in family medicine at East Tennessee State University. He received fellowship training in sleep medicine at the University of Michigan. Dr. Siddiqui has been in private practice for more than 10 years. He is a member of the American Academy of Sleep Medicine, American Board of Family Medicine, Tennessee Academy of Family Physicians, American Academy of Family Physicians, and the American Medical Association.

Gwen Crenshaw, NP

Crenshaw is a Nurse Practitioner with five years of experience in Sleep Medicine. Initially earning a BS in Physical Therapy in 1988 from the Medical University of South Carolina, Crenshaw earned her Masters Degree in Nursing from University of Tennessee Knoxville in 1998. She is board certified in Family Medicine and Occupational Health. She has also worked in Occupational Medicine and the Urgent Walk-in Clinic environment for eight years before joining Covenant Health.

Professionals in Behavioral Medicine, Weight Management, Neurology, ENT, Pulmonary, or Urology

Types Of Sleep Disorders

There are more than 84 different types of sleep disorders. Following are a few of the most common:

  • Restless Legs Syndrome (RLS): Neurological movement disorder characterized by abnormal, uncomfortable stinging in the legs that typically occurs or worsens when a person is at rest; a near-constant “pins and needles” feeling that results in constant moving of the legs and prevents a restful sleep.
  • Obstructive Sleep Apnea (OSA): A disorder that occurs when air cannot flow in or out of a person’s nose or mouth although efforts to breathe continue; caused by mechanical and structural problems in the airway that cause interruptions in breathing (i.e., throat muscles and tongue relax, excessive amount of tissue in the airway); results in choking sensations during sleep and is almost always accompanied by snoring between apnea episodes.
  • Insomnia: The most common sleep disorder; described as the inability to initiate or maintain sleep and is associated with daytime fatigue and sleepiness; often the result of stress, illness, environmental factors, or other conditions that throw off a normal sleep schedule. It is important to establish Good Sleep Habits as part of your insomnia treatment.
  • Narcolepsy: A disorder that manifests itself through excessive daytime sleepiness, uncontrollable sleep attacks and muscle weakness triggered by sudden emotional reactions such as laughter or fear; sometimes accompanied by vivid dreamlike scenes or paralysis upon falling asleep or waking.
  • Sleep/Wake Cycle Disorders: A disorder accompanied by symptoms of insomnia or sleepiness at inappropriate times; associated with patients who work rotating schedules, suffer from jet lag, or have insufficient sleep syndrome; can become progressive and chronic, but can be treated with medication and therapy.
  • Chronic fatigue: A disorder that produces an ongoing feeling of tiredness, malaise, sleepiness, boredom, or depression; has various causes and is sometimes associated with a sleep disorder.
  • Parasomnia’s: A disorder that may include nightmares, chest pain, night terrors, sleepwalking and sleep talking; most common in childhood and sometimes worsens during adolescence and adulthood.

Sleep Studies

A complete evaluation typically involves one to two nights of sleep monitoring.

Sleep studies measure factors such as the amount of oxygen in the blood during sleep, the amount of restless movement during sleep, and the time it takes for a person to fall asleep during the day. The following tests are performed at the Parkwest Sleep Disorders Center:

  • A polysomnography is a test that records a variety of body functions during sleep, such as the electrical activity of the brain, eye movement, muscle activity, heart rate, respiratory effort, air flow, and blood oxygen levels.
  • An overnight polysomnography test involves monitoring brain waves, muscle tension, eye movement, respiration, oxygen level in the blood and audio monitoring.
  • A Multiple Sleep Latency Test (MSLT) is a test that measures the excess of daytime sleepiness in an individual. Individuals who fall asleep in less than five minutes are likely to require some type of treatment for sleep disorders.

Most insurance companies provide coverage for evaluation of sleep disorders. Contact your insurance company for details on your policy’s specific conditions.


Once a test has been performed to determine the type of sleep disorder, clinicians determine the appropriate treatment plan for the individual.

Some sleep disorders can be treated with behavioral changes such as losing weight; developing better sleep habits; and avoiding alcohol, caffeine, and sleep medications.

For mild sleep disorders, oral appliances may be effective in keeping the airway open by holding the tongue or jaw forward, increasing the airway space behind the tongue.

Moderate to severe sleep apnea is usually treated with Positive Airway Pressure (such as CPAP, BiPAP, Auto PAP, BiPAP ST, Auto servo ventilation units for central apnea). During this treatment, a patient wears a mask over the nose during sleep, and positive air pressure is directed through the airway and/or nasal passages.

Severe sleep apnea may require surgery in addition to positive airway pressure therapy. Usually a surgeon will suggest the patient utilize the machine for at least a month before pursuing surgery. The most common surgical procedures to treat sleep apnea include removal of adenoids and tonsils, nasal polyps or other growths, or other tissue in the airway and correction of structural deformities.

Good Sleep Habits*

*Information from the American Academy of Sleep Medicine

  • Maintain a regular wake time, even on days off work and on weekends
  • Try to go to bed only when you are drowsy
  • If you are not drowsy and are unable to fall asleep for about 20 minutes, leave your bedroom and engage in a quite activity elsewhere. Do not permit yourself to fall asleep outside the bedroom. Return to bed when, and only when, you are sleepy. Repeat this process as often as necessary throughout the night.
  • Use your bedroom only for sleep, sex, and time of illness.
  • Avoid napping during the daytime. If you nap, try not to do so at the same time every day and for no more than one hour. Mid-afternoon (no later than 3 p.m.) is best for most people.
  • Establish relaxing pre-sleep rituals such as a warm bath, light bedtime snack, or ten minutes of reading.
  • Exercise regularly. Confine vigorous exercise to early hours, at least six hours before bedtime, and do mild exercise at least four hours prior to bedtime.
  • Keep a regular schedule. Regular times for meals, medications, chores, and other activities help keep the inner clock running smoothly.
  • While a light snack before bedtime can help promote sound sleep, avoid large meals.
  • Avoid ingestion of caffeine within six hours of bedtime.
  • Don’t drink alcohol when sleepy. Even a small dose of alcohol can have a potent effect when combined with tiredness.
  • Avoid the use of nicotine close to bedtime or during the night.
  • Sleeping pills should be used only conservatively. Most doctors avoid prescribing sleeping pills for periods longer than three weeks.
  • Do not drink alcohol while taking sleeping pills or other medications.

The Sleep Quiz

Have you been told that you are a very loud snorer or that you choke, gasp, or have pauses in your breathing during sleep?

Do you feel tired and groggy on awakening or often get sleepy during waking hours, even if you have had 7-8 hours of sleep? Can’t sleep more than 5-6 hours

Do you often and easily doze off while reading, watching TV, sitting in meetings, or sitting in traffic

Are you experiencing any of the following?

  • Slowed thinking and reactions and/or frequent errors and mistakes
  • Difficulty listening to what is said or understanding directions
  • Morning headaches or dry mouth
  • Impatience, irritability, diminished sexual function, depression, or negative mood
  • Fatigue or reduced energy compared to recent years
  • Do you have high blood pressure, congestive heart failure, atrial fibrillation, acid reflux or recent onset diabetes?
  • Do you ever experience unpleasant, restless, creepy, crawly, pulling, or gnawing feelings in your legs, associated with an urge to move your legs?
  • Has your weight increased rapidly? Are you overweight? Do you have a large neck?

All these symptoms and health problems can be related to sleep disorders. If they describe you, discuss them with your physician. A referral to a doctor who specializes in sleep medicine may be indicated.

Berta Bergia, M.D., FAASM
Medical Director of PW Sleep Disorders Center
Diplomate of the American Board of Sleep Medicine