Motion sickness (MSK) is a latent neurologic disorder, active only when the vestibular-cortical pathways are disrupted.  It is associated with migraines though the nature and cause of the disorder remain unclear. Patients with MSK are considered to have normal neurological exams. We have identified a selective vibratory deficit in children and adults with motion sickness at rest, present even in the absence of acute symptoms.

We reviewed the records of 132 adults, ages 18-60 years old, and 59 children, ages 5-17 years old, who experienced MSK. In the adult group with MSK alone, 80% head tuning fork abnormalities detected in their lower extremities. This occurred at rest and not during acute exacerbation of MSK.  In the pediatric group with MSK alone, 63% showed tuning fork abnormalities. MSK onset was mainly in childhood. MSK was present in 68% of adults with migraines (n=233), though a similar pairing in children and teenagers was less common.

Selective vibration sensory deficits were present in most children and adults with MSK at rest. This is a novel clinical finding which suggests involvement of central activation pathways, similar to migraines.