The vestibular organs of the inner ear provide the brain with information about changes in head movement. If the vestibular system is not functioning properly, dizziness, vertigo, imbalance, spatial disorientation, and other symptoms can result.
An imbalance of signals between the two sides of the vestibular system will lead to vertigo or dizziness as the brain stem will not be able to coordinate the conflicting signals together.
Some of the commonest causes of dizziness involve a vestibular imbalance or conflict.
“I was feeling run down after a flu. I had noticed slight light-headedness a day or two previously. I awoke with severe spinning and nausea, I was sick and couldn’t get out of bed. After a couple of days I was able to get up, but since then I’ve been dizzy when I move about. I’ve not been able to return to work or walk outside. The doctors said there was nothing seriously wrong and that the symptoms would settle down. They haven’t, and I’m feeling really frustrated.”
Signals from the inner ear travel to the brain stem along the vestibular nerve. If the nerve from one side cannot transmit these signals, then a vestibular imbalance will result. One of the commonest causes of reduced vestibular nerve function is ischaemia (lack of blood), due to irritation from a virus. Occasionally, a bacterial infection may cause the ischaemia, and this may also affect the inner ear, causing loss of hearing. This is known as labrynthitis.
These conditions respond very well to a tailored course of vestibular exercises. Symptoms normally settle over 8-12 weeks.
Benign Positional Paroxysmal Vertigo (BPPV)
“I get a sudden attack of dizziness everytime I tilt my head back to look up at the ceiling or turn my head to one side. After 10-30 seconds it subsides. It’s also difficult to roll onto my side in bed or to bend forwards. I am fine so long as I avoid these positions, but it interferes with my life and I’m frightened about getting an attack in public.”
This is the commonest form of vestibular problem. Roughly 20% of all dizziness is due to BPPV. It is usually treated easily and effectively with a simple manipulation, see the BPPV section for more details.
” I have random episodic attacks of dizziness. They may last for hours. I notice a pressure or ‘fullness’ in one ear, I find it difficult to hear on that side and I often hear ‘ringing’, before I’m violently dizzy and sick. The attacks seem to be worsening. In between the attacks I’m ok, but I am losing hearing on one side.”
This is a disease affecting the concentration of fluids within the inner ear. Whilst it does often mean a progressive loss of hearing on one side, the dizziness and tinitus (ringing in the ear) can be effectively managed with vestibular training, allowing a return to normal life.
There are many other less common vestibular causes of dizziness, for example migraine, mal de debarquement (a sensation of rocking that persists after a cruise or other travel), or exposure to ototoxins (drugs or chemicals that are harmful to the inner ear.
For more information on vestibular causes of dizziness see the excellent and informative website of the Vestibular Disorders Association .
See Non Vestibular causes of dizziness here