What is videonystagmograpy?
Videonystagmography (VNG) is a complete diagnostic system for recording, analyzing and reporting involuntary eye movements, called nystagmus, using video imaging technology.A series of tests used to determine the causes of a patient’s dizziness or balance disorders. If dizziness is not caused by the vestibular portion of the inner ear, it might be caused by the brain, by medical disorders such as low blood pressure, or by psychological problems such as anxiety.
How is a VNG performed?
There are four main parts to the VNG, The cameras record the eye movements and display then on a video/computer screen. This allows the examiner to see how the eyes move which is very helpful in assessing balance system health.
- The saccade test: evaluates rapid eye movements.
- The tracking test: evaluates movement of the eyes as they follow a visual target.
- The positional test: measures dizziness associated with positions of the head.
- The caloric test: measures responses to warm and cold water circulated through a small, soft tube in the ear canal.
Benign Paroxysmal Positional Vertigo (BPPV)
The sudden sensation that you’re spinning or that your head is spinning inside. This could also be characterized as brief episodes of mild to intense dizziness. Dizziness is generally thought to be due to debris which has collected within a part of the inner ear. This debris can be thought of as “ear rocks”, although the formal name is “otoconia”. Ear rocks are small crystals of calcium carbonate derived from a structure in the ear called the “utricle”. The utricle may have been damaged by head injury, infection, or other disorder of the inner ear, or may have degenerated because of advanced age.
About 20% of all dizziness is due to BPPV. While BPPV can occur in children, the older you are, the more likely it is that your dizziness is due to BPPV. About 50% of all dizziness in older people is due to BPPV. In a recent study, 9% of a group of urban dwelling elders were found to have undiagnosed BPPV .
Symptoms of BPPV:
Symptoms of benign paroxysmal positional vertigo are triggered by specific changes in the position of your head, such as tipping your head up or down, and by lying down, turning over or sitting up in bed. You may also feel out of balance when standing or walking. The most common noticeable symptoms consist of nausea, lightheadedness, and imbalance.