Motion Sickness


Motion Sickness, Car Sick, Seasick, Sea Sickness, Air Sickness

  • Definition
  1. Non-vertiginous Dizziness and associated Nausea or Vomiting typically provoked by motion on travel in a car, boat, or airplane
  • Pathophysiology
  1. Discordance between vestibular, visual and proprioceptive signals
  2. Vestibular/proprioceptive systems sense movement
  3. Visual system fails to sense movement
  • Risk Factors
  1. Prior history of Motion Sickness (best predictor of future events)
  2. Female gender
  3. Children ages 2 to 15 years
  4. Conditions predisposing to Nausea (e.g. first trimester pregnancy, Migraine Headaches)
  • Symptoms
  1. Occur in reponse to specific stimuli (e.g. car or boat travel)
  2. Primary
    1. Nausea or Vomiting to Retching in severe cases
    2. Non-vertiginous Dizziness
  3. Associated
    1. Headache
    2. Malaise
    3. Cold diaphoresis
    4. Flushing
    5. Incapacitation may occur in severe cases
  • Prevention
  1. Reduce overall exposures
    1. Avoid travel during difficult weather conditions (e.g. storms, large waves, air turbulence)
    2. Avoid travel with difficult terrain (up and down, tight turns, frequent acceleration and deceleration)
    3. Avoid travel where visibility is reduced (e.g. fog, clouds)
  2. Avoid provocative motions
    1. Avoid complex, multiple axis motions
    2. Prefer linear motion to rotary motion
    3. Prefer horizontal motion to vertical motion
    4. Prefer high frequency motion to low frequency motion
  3. Favor positions with least motion
    1. Plane
      1. Over wing
    2. Car
      1. Front seat (driver or passenger)
      2. Face forward
    3. Boat
      1. Level closest to water surface
      2. Face toward the waves and away from the rocking bow
    4. Bus
      1. Sit near front at the lowest level
      2. Face forward
    5. Train
      1. Sit at lowest level
      2. Face forward
  4. Desensitization
    1. Start traveling during calm conditions
    2. Gradually increase motion exposure
    3. Anticipate symptoms with increasing exposure
      1. Attempt to continue exposure despite symptoms
      2. Use measures listed here to reduce Motion Sickness symptoms
      3. At onset of Vertigo, attempt to reorient immediately
  5. Keep visual system in sync with motion
    1. Avoid near work (e.g. reading, photography) while traveling
    2. Face forward toward the motion or direction of travel
    3. Try to remain in vehicle spaces where the horizon is visible
      1. Focus on a distant horizon point
      2. If horizon is not visible, close eyes with head still (or consider sun glasses)
  6. Keep body in sync with motion
    1. Tilt head into a turn
    2. Steer the vehicle (or touch part of the wheel if possible)
    3. Stand with knees bent and move with the vehicle motion
    4. Stay active with the motion (e.g. swim in water, walk around vehicle)
      1. If unable, lie supine or at 30 degrees reclined (or brace head to prevent motion)
  7. Other measures
    1. Avoid Alcohol
    2. Stay hydrated
    3. Eat before travel and maintain nourishment during travel with light, low-fat, low-acid meals
    4. Attempt to sleep
    5. Stay in dry, comfortable, well-ventilated areas
    6. Avoid Nauseating stimuli (exhaust, smell of vomit)
    7. Keep thoughts positive
      1. Listen to music
      2. Avoid talk of Motion Sickness
  1. Precautions
    1. Not recommended in age under 10 years
    2. Anticholinergic effects are common (but less than Antihistamines listed below)
  2. Transdermal Scopolamine patch (Transderm-Scop) - preferred
    1. Apply behind one ear at least 4 hours before travel
    2. Replace patch every 72 hours
    3. One box contains 4 patches (but pharmacies may dispense individual patches)
    4. Effective for Motion Sickness prevention
      1. Gil (2012) Clin Neuropharmacol 35(1): 37-9 [PubMed]
      2. Spinks (2011) Cochrane Database Syst Rev (6): CD002851 [PubMed]
    5. A second patch has been safely added if the first does not offer adequate relief (off label use, and higher than recommended dose)
      1. Bar (2009) Pharmacotherapy 29(9): 1082-8 [PubMed]
  3. Oral Scopolamine
    1. Scopolamine 0.4 to 0.6 mg starting one hour before travel and then every 8 hours as needed
    2. Not as effective as transdermal Scopolamine
  • Management
  • Other medications
  1. Most effective
    1. Scopolamine (see above)
  2. Moderately effective
    1. Cinnarazine (OTC in Europe and Mexico, not available in U.S.)
      1. Dose: 30 mg at two hours prior to travel, then 15 mg every 8 hours as needed
    2. Promethazine
      1. Dose: 25 mg PO/PR at 30-60 minutes before travel, then every 12 hours as needed
  3. Minimally effective
    1. Cyclizine (Marezine)
    2. Dimenhydrinate (Dramamine)
    3. Diphenhydramine
    4. Meclizine (Antivert)
  4. Ineffective
    1. Ondansetron (Zofran)
    2. Ginger root