Vertigo and earthquakes
Why do people feel dizzy after an earthquake? Dr. MOHAN KAMESWARAN explains.
VERTIGO or dizziness is a commonly recognised phenomenon after an earthquake. After the recent earthquake, there has been a flood of worried patients who have symptoms of vertigo.
Vertigo is a subjective sensation of movement or rotation experienced by a person in relation to his/her environment. It occurs when there is a mismatch or discrepancy in the information sent to the brain from three organs - the labyrinth (the inner ear), the eye and the sensation from the lower limbs while standing. Of these, the most sensitive and primary input is from the labyrinth.
The labyrinth is, in many ways, responsible for our erect posture. Even the slightest stimulation of this area gives a sensation of vertigo. This happens when the head moves from a static position. This sends the information to the brain from both sides and the brain interprets the information to understand the position of the head and the body. This is accompanied by information from the eyes and the lower limbs, which should corroborate each other.
Thus when we travel by air or sea, there may be a mismatch from the labyrinth (which is stimulated) and the eye (which may be suggest that we are stationary) resulting in vertigo (air or sea sickness).
During an earthquake, there is powerful low frequency stimulation of the labyrinth. In animals, it serves as an alert. In humans, however, this survival instinct has been more or less lost but the stimulus of the labyrinth can still lead to an unpleasant sensation we call vertigo. This is more so if the person suffers a labyrinthine dysfunction with a prior history of vertigo.
Send this article to Friends by