Dizziness and Vertigo

Dizziness – if you have ever had it, it is an awful condition to experience. Whether you are a frail grandmother or a strong, able-bodied fireman, dizziness will affect you both equally and disable you just as surely. There are many causes of dizziness but this article will focus only on the dizziness and vertigo caused by conditions that affect the ear and the balance system. What is vertigo? Why is it important? Vertigo is a special type of ear-related dizziness with a hallucination of movement. This means not only does the patient feels he/she is dizzy, they describe the room or floor as moving but we know it is not. Vertigo is very specific for dizziness from our ear and balance system.

 

Our inner ear system consists of the inner cochlea (for hearing) and the vestibular organs (for balance). The fluid that exists between these two systems is the same. Hence in some conditions, we may experience balance problems with hearing loss. In addition, the balance organ of each ear consists of three semi-circular bony tubes in which the fluid sits. These tubes are orientated to pick up movement in three directions (up-down, rotate right-left and sideways right-left). With the semicircular tubes of the other ear set in a mirror image of one another, the head (therefore the brain) is able to sense head movement in all directions of movement. Hence the combined signals from these semicircular tubes (of the balance organs), from both the eyes and from the positional sense organs in our neck muscles, will tell our brain where our head sits in relation to the body, and whether there is motion. The brain does the rest.

 

Perhaps the simplest way to look at ear-related dizziness is to understand

1.    conditions that affect the entire inner ear (hearing and balance) and

2.    conditions that affect only the balance organs alone (balance).

Inner ear diseases are either stimulative (e.g. Meniere’s disease) or paralytic (e.g. viral-induced labyrinthitis), but both will cause dizziness. With Meniere’s-like diseases, the inner ear fluids are under higher pressure, and therefore the patient experiences hearing loss, ear fullness sensation, and dizziness with vertigo. Conversely when the inner ear organ is paralysed / damaged e.g. by a virus of the inner ear, the patient experiences hearing loss but with their vertigo moving in the opposite direction. Of course this s only of academic interest as the patient would not know this as dizziness is simply dizziness. 

Specific types of surgery and drugs can also cause vertigo, either by stimulating or paralyzing, the inner ear function. Brain tumors and strokes of the brain may also cause vertigo and hearing loss too but usually there are other important symptoms that suggest this like loss of vision, speech, etc.

As for conditions that affect the balance organ only, there is only vertigo without hearing loss or symptoms. Remember the semicircular tubes that measure movement in one direction? When they are stimulated / paralysed, we get vertigo. An example of a common stimulative condition that causes only vertigo is benign paroxysmal positional vertigo (BPPV). Patients suddenly feel the room is turning without experiencing any hearing problems, and that the condition only improves if they keep their head still. They will also feel nauseous, vomit, have a racing heart, look pale and sweaty but these symptoms are all secondary to the vertigo. Treat the BPPV, and the rest gets better!

In the next article, I will explain the rationale of treatment.

The Chinese version of this article was published in Hong Kong Economic Journal on October 28, 2013.