LCD L36593: Polysomnography

This is a limited coverage LCD that requires accreditation for all sleep disorder clinics providing Medicare services.

Sleep studies and polysomnography (PSG) refer to the continuous and simultaneous monitoring and recording of various physiological and pathophysiological parameters of sleep for 6 or more hours with physician review, interpretation and report. The studies are performed to diagnose a variety of sleep disorders and to evaluate a patient's response to therapies such as continuous positive airway pressure (CPAP). PSG is distinguished from sleep studies by the inclusion of sleep staging.

Criteria for coverage of Diagnostic Tests

All reasonable and necessary diagnostic tests performed by sleep disorder clinics (Sleep Disorder Centers or Laboratories for Sleep Related Breathing Disorders) given for the medical conditions listed under Medical Conditions for Which Testing is Covered are covered, when all of the following criteria are met:

• The documentation should be retained in the patient's medical record.

• For a study to be reported as a polysomnogram, sleep must be recorded and staged.

PSG is defined to include, but is not limited to, the following:

• A 1-4 lead electroencephalogram (EEG) to measure global neural encephalographic activity using electrodes placed on the scalp

• Electrooculogram (EOG) to measure eye movements using electrodes placed near the outer canthus of each eye

• A submental electromyogram (EMG) to measure submental electromyographic activity using electrodes placed over the mentalis, submentalis muscle, and/or masseter regions

• Rhythm electrocardiogram (ECG) with 2 or 3 chest leads

• Nasal and/or oral airflow

• Ventilation and respiratory effort by chest-wall and abdominal movement measured using strain gauges, piezoelectric belts, inductive plethysmography, impedance or inductance pneumography, endoesophageal pressure, or by intercostal EMG

• Gas exchange (oxygen saturation (SpO2)) by oximetry, transcutaneous monitoring, or end-tidal gas analysis

• Extremity muscle activity, motor activity-movement using EMG

• Body positions via mercury switches or by direct observation

• Recordings of vibration (frequency and/or volume) may be recorded

• Transcutaneous CO2, esophageal pH, penile tumescence, and bipolar EEG

Sleep studies are performed in a hospital, sleep laboratory or by an Independent Diagnostic Treatment Facility (IDTF) that is supervised by a physician (MD/DO) trained in analyzing and interpreting the recordings and should be attended by a trained technologist. (For exception to the attendance requirement, see the section on sleep apnea below).

Medical Conditions for Which Testing is Covered

Diagnostic testing will only be covered if the patient demonstrates clinical evidence of 1 or more of the following conditions:

1. NARCOLEPSY:

The diagnosis of narcolepsy is usually confirmed by an overnight sleep study (PSG) followed by a multiple sleep latency test (MSLT). MSLT involves several 20-minute nap opportunities offered at 2-hour intervals. MSLT objectively assesses sleep tendency by measuring the number of minutes it takes the patient to fall asleep. Conversely, the maintenance of wakefulness test (MWT) requires the patient to try to stay awake. MSLT is the better test for demonstration of sleep-onset rapid eye movement (REM) periods, a determination that is important in establishing the diagnosis of narcolepsy. To ensure validity, proper interpretation of the MSLT can only be made following a PSG performed on the preceding night.

The following measurements are normally required to diagnose narcolepsy:

• Polysomnographic assessment of the quality and quantity of nighttime sleep;

• Determination of the latency of the REM episode;

• MSLT; and

• The presence of REM-sleep episodes.

Initial PSG and MSLT occasionally fail to identify narcolepsy. Repeat PSG may be indicated:

• if the first study is technically inadequate due to equipment failure;

• if the subject could not sleep or slept for an insufficient amount of time to allow a clinical diagnosis;

• if initiation of therapy or confirmation of the efficacy of prescribed therapy is needed; or

• if the results were inconclusive or ambiguous.

2. SLEEP APNEA:

The diagnosis of sleep apnea may be made using the following modalities:

a. PSG performed in a sleep laboratory; or

b. Unattended home sleep monitoring device of Type II; or

c. Unattended home sleep monitoring device of Type III; or

d. Unattended home sleep monitoring device of Type IV, measuring at least 3 channels.

Sleep apnea may be due to an occlusion of the airway (obstructive apnea), absence of respiratory effort (central sleep apnea) or a combination of these factors (mixed sleep apnea).

Obstructive sleep apnea (OSA) may be caused by 1 of the following:

• Reduced upper airway caliber due to obesity;

• Adenotonsillar hypertrophy;

• Mandibular deficiency;

• Macroglossia;

• Upper airway tumor;

• Excessive pressure across the collapsible segment of the upper airway;

• Activity of the muscles of the upper airway insufficient to maintain patency.

For patients with severe and unambiguous OSA, the initiation of treatment with nasal CPAP may be incorporated into the diagnostic study night. A "split-night" study (initial diagnostic polysomnogram confirming the diagnosis of OSA followed by CPAP titration during PSG on the same night) may be an alternative to 1 full night of diagnostic PSG followed by a second night of titration as long as:

• CPAP titration is carried out for more than 3 hours; and

• PSG or home sleep study (HST) documents that CPAP eliminates or nearly eliminates the respiratory events during REM and non-rapid eye movement (NREM) sleep.

Repeat PSG or HST for diagnosing sleep apnea requires documentation justifying the medical necessity for the repeated test. Repeat PSG may be indicated:

• if the first study is technically inadequate due to equipment failure;

• if the subject could not sleep or slept for an insufficient amount of time to allow a clinical diagnosis;

• if the results were inconclusive or ambiguous; or

• if initiation of therapy or confirmation of the efficacy of prescribed therapy is needed.

Follow-up PSG or HST is not routinely indicated for patients treated with CPAP, whose symptoms continue to be resolved with CPAP treatment. Follow-up PSG may be indicated; however, under the following circumstances:

• After substantial weight loss has occurred in patients on CPAP for treatment of sleep-related breathing disorders to ascertain whether CPAP is still needed at the previously titrated pressure;

• After substantial weight gain has occurred in patients previously treated with CPAP successfully, who are again symptomatic despite the continued use of CPAP, to ascertain whether pressure adjustments are needed; or

• When clinical response is insufficient or when symptoms return despite a good initial response to treatment with CPAP.

3. PARASOMNIA:

Normally, a clinical history, neurologic examination, and routine EEG obtained while the patient is awake and asleep are often sufficient to establish the diagnosis and permit the appropriate treatment of sleep-related epilepsy. In addition, common, uncomplicated, non-injurious parasomnias, such as typical disorders of arousal, nightmares, enuresis, somniloquy, and bruxism can usually be diagnosed by clinical evaluation alone.

PSG is indicated to provide a diagnostic classification or prognosis when both of the following exist:

• When the clinical evaluation and results of standard EEG have ruled out a seizure disorder; and

• In cases that present a history of episodes during sleep that result in harm to the patient or others.

When PSG is performed for the diagnosis of parasomnias, the following measurements are obtained:

• Sleep-scoring channels (EEG, EOG, chin EMG);

• EEG using an expanded bilateral montage;

• EMG for body movements;

• Audiovisual recording; and

• Documented technologist observations.

4. Other Respiratory Disorders: This diagnostic category includes breathing disorders that are not principally defined by obstructive or central apnea/hypopnea or the upper airways resistance syndrome (UARS).

PSG is indicated for patients with neuromuscular disorder and sleep-related symptoms to evaluate symptoms of sleep disorder that are not adequately diagnosed by obtaining a sleep history, assessing sleep hygiene, and reviewing sleep diaries.

PSG and HST are not indicated to diagnose chronic lung disease. Nocturnal hypoxemia in patients with chronic obstructive, restrictive, or reactive lung disease is usually adequately evaluated by oximetry and does not require PSG or HST. However, if the patient’s symptoms suggest a diagnosis of OSA or periodic limb movement disorder (PLMD), indications for PSG are the same as for those disorders in patients without chronic lung disease.

5. Restless Legs Syndrome (RLS) and PLMD: RLS is a neurologic disorder characterized by disagreeable leg sensations that usually occur at rest or before sleep and are alleviated by motor activity. Periodic limb movements are involuntary, stereotypic, repetitive limb movements that may occur during sleep and usually involve the legs and, occasionally, the arms. Periodic limb movements during sleep often accompany RLS. PLMD is a sleep disorder characterized by periodic limb movements that cause frequent arousals and lead to insomnia or excessive daytime sleepiness. The results of PSG studies from patients with severe RLS often show prolonged sleep latencies, decreased sleep efficiency, increased number of awakenings, significant reductions in total sleep time, and decreased amounts of slow-wave sleep. Patients with PLMD often have frequent periodic limb movements that are associated with arousals and awakenings, reduced total sleep time, and decreased sleep efficiency.

PSG is indicated when a diagnosis of PLMD is considered because of complaints by the patient or an observer of repetitive limb movements during sleep and frequent awakenings, fragmented sleep, difficulty maintaining sleep, or excessive daytime sleepiness.

Limitation of Coverage:

Sleep testing performed using an unattended portable monitor (HST) for the diagnosis of OSA must adhere to the guidelines specified in "Clinical Guidelines for the Use of Unattended Portable Monitors in the Diagnosis of OSA in Adult Patients". If discrepancies exist between these guidelines and this LCD, the parameters in this LCD take precedence. HST is covered only for the diagnostic study of OSA and for no other indications.

HSTs may be used in addition to a face-to-face clinical assessment by the treating physician, Epworth Sleepiness Scale, and physical examination to diagnose OSA; specifically, it is intended only for those patients who exhibit clinical signs and symptoms of OSA.

HST is not covered for patients with certain medical comorbidities, including:

• Moderate to severe pulmonary disease (e.g., patients on oxygen or regular bronchodilator use)

• Neuromuscular disease affecting muscles of respiration

• Congestive heart failure

• Suspicion of the presence of other sleep disorders, i.e., narcolepsy, parasomnia, or periodic limb movements of sleep

• other respiratory disorders, impotence, RLS

HST scoring must be performed by an individual certified by the Board of Registered Polysomnographic Technologists (BRPT) as a Registered Polysomnographic Technologist (RPSGT), or equivalent, or by a polysomnographic technician under the supervision of a RPSGT, or equivalent. RPSGTs and polysomnographic technicians must meet the standards for such individuals promulgated by the American Academy of Sleep Medicine Standards for Accreditation of Laboratories for Sleep Related Breathing Disorders, and be licensed or certified by the state in which they practice, if such licensure or certification exists. The laboratory physician must review the entire raw data recording for every patient studied.

PSG, HST and MSLT are not covered in the following situations:

1. For the diagnosis of patients with chronic insomnia.

Snoring and nasal obstructive signs and symptoms are not, in and of themselves, indications for PSG; however, they may be indications of sleep apnea when other findings are also present. Other causes of sleepiness should be ruled out via a sleepiness scale before performing a sleep study.

2. To preoperatively evaluate a patient for laser-assisted uvulopalatopharyngoplasty without clinical evidence that OSA is suspected;

N/A