Obstructive Sleep Apnea and Narcolepsy

Obstructive Sleep Apnea (OSA) Definition

• Obstructive events refer to moments in which there is cessation of airflow due to obstruction in the upper airway.

  • Different from Central Sleep Apnea in which brain fails to send signals to body to breathe

• During these episodes, the muscles that promote breathing (the diaphragm and chest wall musculature) continue to work.

• The obstruction is caused by the throat muscles relaxing, eventually closing the throat for short periods.

• Apneas can lead to moments of asphyxia (O2 decreases and CO2 increases)

• During apneas, we awaken to restart breathing'

• Episodes can happen multiple times per hour through the sleep period

• People are generally unaware of these occurrences

• 2 – 8% of the population suffer from OSA

Symptoms of OSA

• Excessive daytime sleepiness (EDS)

• Fatigue (not necessarily sleepiness)

• Unrefreshing sleep

• Insomnia

• morning headaches (brain starving for O2)

• Dry mouth (try to open mouth to improve breathing)

• Awaken to urinate multiple times at night

• Bed partner complains about snoring, apneas, choking sounds, restlessness

Symptoms of OSA in children

• Happen only to about 2% of children

  • longer sleep time than normal

  • more effort when breathing

  • irritability

  • bed-wetting

  • morning headaches

  • etc

Tongue Size and Breathing for OSA

• Tongue size

  • positioning of the tongue complicates eating, drinking, and breathing

    • We choke more easily than other animals

    • The longer tissues of the soft palate at the back of the throat make blockage easier after routine exhalation

• Breathing

  • Muscle tone

    • Tone decreases during NREM and more so during REM

  • Laying down causes gravitational compression of upper airway

Upper Airway Anatomy and Breathing/OSA

• Our upper airways are NOT a rigid tube but rather a flexible, collapsible tube formed mainly by soft tissue (e.g., muscles, fat, mucosa)

  • Space behind our nose and palate

  • Space behind our tounge

• Sometimes, when breathing in, your collapsable tube sometimes collapses, especially when lying down

• Why?

  • Reduced muscle activation in sleep

  • Weight of tongue

  • Weight of neck - worse with obesity

  • Worse when supine

Risk factors for SDB

• Nasal problems

• Large Tonsils

• Large neck

• Large Tongue, small mouth, facial deformity

• Obesity

• Alcohol

Risk Factors for OSA in adults

• Obesity and neck circumference

• Airway conformation

• Males over Females

• Older age

• menopause

• NAsal problems

• history of OSA

• consumption of alcohol

• Exposure to cigarette smoking

• sleeping supine

• etc

Snoring

• Habitual snoring is reported in 24 % of women and 40% of men and increases with age

• Snoring may be a sign or a precursor of OSA

• Old studies showed that habitual snoring might increase the risk for cardiovascular disease, stroke, hypertension, and EDS

  • However, many of these studies did not differentiate between simple snoring (primary) and snoring associated with obstructive sleep apnea

Diagnosis of OSA

• Physical examination and medical history

• Parents should be asked about children’s snoring

• Ear, nose and throat (ENT, aka otolaryngologist) or sleep specialist for additional studies and evaluation

• Polysomnography

Health consequences of OSA

• Hypertension

• Stroke

• Headaches

• Obesity

• Seizures

• Diabetes

• Pulmonary hypertension

Treatment for OSA

• Lifestyle changes -losing weight and avoiding alcohol and smoking

• If lifestyle changes do not eliminate OSA:

  • Positional therapy

  • Oral appliances

  • Traditional surgery / uvulopalatopharyngoplasty (UPPP).

  • Alternative surgery procedures (aser and radiofrequency tissue ablation, somnoplasty)

    • Discouraged

  • Continuous positive airway pressure (CPAP)

Tracheostomy

• The original treatment

• The surgeon makes an opening through the neck into the airway & inserts a tube

• Nearly 100% successful

• Requires a quarter-size opening in the throat, producing potentially other medical and psychological problems associated with recovery

• Today, this operation is performed rarely, usually only if sleep apnea is life threatening.

Positional Therapy

• Expensive pillow that you strap onto yourself, so you cannot sleep on back

  • Especially effective for supine issues

Oral Appliances

• Indicated for those who have mild/moderate OSA

• Mandibular advancement device (MAD). This is the most widely used dental device for sleep apnea. MAD forces the lower jaw forward and down slightly, which keeps the airway open.

• Tongue retraining device (TRD). This is a splint that holds the tongue in place to keep the airway as open as possible

UPPP Surgery

• Removes soft tissue on the back of the throat, including the uvula (the soft flap of tissue that hangs down at the back of the mouth) and parts of the soft palate and the throat tissue behind it. If tonsils and adenoids are present, they are removed

• Goals

  • Increase the width of the airway at the throat's opening

  • Block some of the muscle action in order to improve the ability of the airway to remain open

• Very painful, prone to infection, regurgitation of fluids through nose

• only 50% efficacy

• Not recommended

Continuous Positive Air Presssure (CPAP)

• The best treatment and most commonly employed for moderate and severe OSA

• CPAP may not recommended for patients who have mild-sleep apnea and do not have daytime sleepiness (usually not much benefit for these patients)

• The device itself is a machine weighing about 5 pounds that fits on a bedside table.

•  A mask containing a tube connects to the device and fits over just the nose.

• The machine supplies a steady stream of air through a tube and applies sufficient air pressure to prevent the tissues from collapsing during sleep.

Side Effects of CPAP and Problems

• Hard to get accustomed to, frightens away partners

• may actually sleep less at start of treatment

• problems related to mask that can be uncomfortable, or leakages of air

CPAP effects on sleep and wakefulness

• CPAP improves both objective and subjective measures of sleep. After using CPAP regularly many patients report the following benefits:

  • Restoration of normal sleep

  • more alertness, less anxiety and depression

  • better productivity, concentration and memory

Medications for OSA

• Modafinil and Armodafinil (dont need to know names)

  • Increase in wake promoting NTs like dopamine, norepinephrine and histamine

• Adjunctive treatment only – it can mask the sleepiness but does not treat the apneas and low O2 in the blood that cause long term issues

Definition of Narcolepsy and Cataplexy

• The two primary symptoms in narcolepsy are related to its name (numbness attack):

  • Excessive daytime sleepiness, with frequent daily sleep attacks or a need to take several naps during the day

    • The naps or “attacks” are refreshing

• Temporary and sudden muscle weakness (cataplexy), usually brought on by strong emotions, such as laugher or, less frequently, anger

  • The muscles most frequently involved are knees and jaw

• Cataplexy is a unique and distinctive symptom for narcolepsy (pathognomonic)

  • Narcoleptics experience all stages of sleep but start by going directly in REM

Additional symptoms of Narcolepsy

• Micro-sleep episodes, in which the patient behaves automatically but without conscious awareness (automatic behaviors)

• Sleep paralysis

  • REM Intrusions

    • Dreamlike states between waking and sleeping (called hypnagogic hallucinations )

• Sleep Onset Rapid Eye Movements Periods (SOREMP)

Etiology of Narcolepsy

• Narcolepsy is a neurological sleep disorde

• It is not caused by mental illness or psychological problems

  • most likely a result of number of genetic abnormalities, with environmental trigger such as a virus or vaccine (flu)

• Lesions at the middle of the Thalamus induce narcolepsy (Von Economo)

Autoimmune response and Narcolepsy

• 20% of normal people have an HLA (immune system marker) associated to development of narcolepsy but only few will develop the disorder; but nearly 100% of those with narcolepsy have the HLA marker

• The “predisposed” immune system gets in contact with the flu virus/vaccine and then mistakes its own hypocretin (orexin) cells for germs and kills them

Diagnosis of Narcolepsy

• Obtain a detailed history, particularly focused on identifying cataplexy and sleep attacks and excluding other conditions associated with EDS, such as OSA, insufficient sleep, and circadian rhythm disorders

• Physical examination

• Polysomnography with identified SOREMPs and disrupted or fragmented sleep

• Hypocretin (orexin) level in the CNS

  • if extremely low, indication for narcolepsy

Treatment of Narcolepsy

• Education

  • Patients, family, friends and employers

• Sleep hygiene

• Safety regarding driving and occupational hazards

  • Doctors are under no obligation to report in NY state

  • Patients “must” be symptom free for one year if known to DMV and are driving (doctor attestation)

• Strategic napping

  • Two 15 minutes naps per day usually after lunch and around 5 pm

• Medication