II. Definition
III. Pathophysiology
- Discordance between vestibular, visual and proprioceptive signals
- Vestibular/proprioceptive systems sense movement
- Visual system fails to sense movement
IV. Risk Factors
- Prior history of Motion Sickness (best predictor of future events)
- Female gender
- Children ages 2 to 15 years
- Conditions predisposing to Nausea (e.g. first trimester pregnancy, Migraine Headaches)
V. Symptoms
VI. Prevention
- Reduce overall exposures
- Avoid travel during difficult weather conditions (e.g. storms, large waves, air turbulence)
- Avoid travel with difficult terrain (up and down, tight turns, frequent acceleration and deceleration)
- Avoid travel where visibility is reduced (e.g. fog, clouds)
- Avoid provocative motions
- Avoid complex, multiple axis motions
- Prefer linear motion to rotary motion
- Prefer horizontal motion to vertical motion
- Prefer high frequency motion to low frequency motion
- Favor positions with least motion
- Plane
- Over wing
- Car
- Front seat (driver or passenger)
- Face forward
- Boat
- Level closest to water surface
- Face toward the waves and away from the rocking bow
- Bus
- Sit near front at the lowest level
- Face forward
- Train
- Sit at lowest level
- Face forward
- Plane
-
Desensitization
- Start traveling during calm conditions
- Gradually increase motion exposure
- Anticipate symptoms with increasing exposure
- Attempt to continue exposure despite symptoms
- Use measures listed here to reduce Motion Sickness symptoms
- At onset of Vertigo, attempt to reorient immediately
- Keep visual system in sync with motion
- Avoid near work (e.g. reading, photography) while traveling
- Face forward toward the motion or direction of travel
- Try to remain in vehicle spaces where the horizon is visible
- Focus on a distant horizon point
- If horizon is not visible, close eyes with head still (or consider sun glasses)
- Keep body in sync with motion
- Tilt head into a turn
- Steer the vehicle (or touch part of the wheel if possible)
- Stand with knees bent and move with the vehicle motion
- Stay active with the motion (e.g. swim in water, walk around vehicle)
- If unable, lie supine or at 30 degrees reclined (or brace head to prevent motion)
- Other measures
VII. Management: Scopolamine (first-line)
- Precautions
- Not recommended in age under 10 years
- Anticholinergic effects are common (but less than Antihistamines listed below)
- Transdermal Scopolamine patch (Transderm-Scop) - preferred
- Apply behind one ear at least 4 hours before travel
- Replace patch every 72 hours
- One box contains 4 patches (but pharmacies may dispense individual patches)
- Effective for Motion Sickness prevention
- A second patch has been safely added if the first does not offer adequate relief (off label use, and higher than recommended dose)
- Oral Scopolamine
- Scopolamine 0.4 to 0.6 mg starting one hour before travel and then every 8 hours as needed
- Not as effective as transdermal Scopolamine
VIII. Management: Other medications
- Most effective
- Scopolamine (see above)
- Moderately effective
- Cinnarazine (OTC in Europe and Mexico, not available in U.S.)
- Dose: 30 mg at two hours prior to travel, then 15 mg every 8 hours as needed
- Promethazine
- Dose: 25 mg PO/PR at 30-60 minutes before travel, then every 12 hours as needed
- Cinnarazine (OTC in Europe and Mexico, not available in U.S.)
- Minimally effective
- Cyclizine (Marezine)
- Dimenhydrinate (Dramamine)
- Diphenhydramine
- Meclizine (Antivert)
- Ineffective
- Ondansetron (Zofran)
- Ginger root