Electronystagmography is an important test done to evaluate patients with vertigo, dizziness and balance problems.

1. ELECTRONYSTAGMOGRAPHY

2. ELECTRONYSTAGMOGRAPHY
• Electronystagmography is an important test done to
evaluate patients with vertigo, dizziness and balance
problems. The study of eye movements provides a
lot of information about the functioning of the brain
and the balance system. ENG is used to second eye
movements in different conditions and with
different tests. By analyzing these movements, we
are able to understand the area affected by the
disorder.

3. • ENG detects eye movements by virtue of a
change in the cornea – retinal potential during
these movements. The changes in potential are
picked up by surface electrodes placed near the
eyes of the patient. Findings of ENG must be
correlated with the history given by the patient
and other neuro – ontological tests to identify
the cause of vertigo or dizziness.

4. FEATURES
• Uses electrodes to record corneo – retinal potential.
• The sensitivity of recording is 2° (which is less than
VNG) due to distantly placed electrodes.
• Able to record horizontal eye movements. Vertical eye
movement recording is not very accurate. Cannot record
torsion.
• The detailed finding of oculomotor tests not possible.

5. • Artefacts due to blinking electromagnetic and electrical
disturbances and EEG activity of the brain can interfere
with the interpretation of results.
• Detection of posterior canal BPPV not possible in many
cases as a torsional element not detected.
• Reviewing and replaying tests not possible.

6. Test Conducted During ENG
• Test for spontaneous nystagmus – Nystagmus is the jerky oscillatory
movement of the eyes caused by disturbances in the balance system. In many
cases, this nystagmus cannot be accurately diagnosed by naked eye examination.
• Test for gaze – This test checks the ability to hold gaze at a point. Patients with
balance disorders may have problems in holding their eyes steady on a fixed
point.
• Saccades – This test checks the ability to move the eyes and appropriately
focus on another object of interest. 3 parameters are measured.
• Smooth pursuit – A light moving like a pendulum is presented to be followed
by the patient with eye movements without moving the head. The ability to track
it with the required velocity and precision is measured.

7. THANK YOU