ABR / ENG tests

[Inna]

Hi,

My doctor in a doubt that I have NA, so to be sure she sent me to two type of tests.
One of them is ENG test.

I will kindly appreciate if you will give me some details concern this test. I did find nothing in web.

Thanks in advance.

Inna.

[satman]

Hi Inna, I had the ENG, Electronic nerve generation.
Pleas dont be scared after I explain it, it sounds worse than it is I promise.
They stick needles {small ones] in your face at certain points and shock you.
The needle penetrates just under the skin, it kinda feels like accupuncture,nothhing really bad,but it does get frustrating.
The shock is worse than the needles.
What this test will tell them is if you cranial nerves [face] are firing .
Mine were not so I had the 7-12 cranial nerve jump.

[lori67]

Hi Inna.

I'm not sure if you're having the test that Satman described or the one that I had.  My ENG was an electronystagmography (try to say that 3 times fast).  It tests your balance function.  The irrigate your ears with cool as well as warm water to stimulate your balance nerve, then they monitor your response by analyzing the amount of nystagmus (irregular eye movements).  In my case, they were able to determine that my balance nerve on my AN side was only functioning at about 41% prior to the surgery.  Since I had no real balance problems, they figured that it had been slowly damaged by the tumor over time, allowing my other ear to compensate gradually, so I never noticed any problems.  It doesn't hurt at all - you get to lie down during it, and it's not bad.  I've had dental cleanings that hurt more than that!

The other test they frequently do is an ABR, which is an Auditory Brainstem Response.  Another easy one on your part - they attach a few electrodes to your head and you just sit back and listen to a bunch of clicks.  The electrodes will monitor your brains response to the clicks to make sure it's just your ear not working right - not something else.

I guess you'll have to ask your doctor which test he's sending you for.  I'm hoping you won't have to have needles put in your face!  Yeeeoooowwwwccchhh!  Satman, you're braver than I am!

Lori

[Inna]

Thank you for your  response.
Inna.

[sgerrard]

I also had the ENG described by Lori. I wore a pair of goggles with little video cameras in them, so they could video my eye movements during the tests. In addition to the "caloric" test, where they put warm and cool water in your ears, they did various movements of my head, and some "follow the moving dot" tests. This testing is sometimes called VENG, or Video-ENG.

I had ABR as well, also as described by Lori. The tests are quite useful, they can identify which, if any, nerves are compromised, and how much so. This is useful in deciding whether treatment might be needed, and can contribute to a decision on which kind of treatment.

I will also put in a plug for getting an MRI with contrast. While the ABR and ENG tests are useful, the definitive test for AN is the MRI. Having had both, I was a bit surprised by the costs - the vestibular lab bill was about the same as the MRI bill.

Steve

[Inna]

Thank you, Steve.

[Emily Murphy]

Whoops!  EMG (electromyelography) is the test with the needles.  It's used for evaluating motor nerve function. ENG stands for electronystagmogram and is an inner ear test designed to test the balance nerve of the inner ear (Cranial Nerve 8 which splits and is also the auditory nerve).  Depending on how thorough the center is, you may sit in a chair that rotates gently from side to side with stick-on electrodes or video to monitor your eye movements.  At some point they will squirt cool and warm water in your ears.  That part of the test may make you dizzy for a short time, but is important because it's the only part of the test that checks one set of semi-circular canals at at time and can give an idea of how much nerve function remains in the affected ear.  Check out www.bcm.edu/oto/cfbd for a description of an ENG.   Emily

[Emily Murphy]

PS - the only way to know for sure about the presence of an acoustic is an MRI (preferable) or CT scan.  My ABR was interpreted as normal, and my calorics were normal, but  I did have an abnormal Rotary Chair, which doesn't tell you if you have an acoustic.  It was found with MRI with contrast.

[Inna]

Thank you for your  response, Emily.
Inna

[OTO]

They should have told you not to eat just before the ENG test.  Because they squirt the water in your ears, and your looking in the goggles, and the table might tilt around, some people get dizzy and possibly a little queasy.

The other EMG test that Satman described uses a mild shock.  It wasn't painful, it felt like someone snapping a rubberband against your skin.   The surprise is what made me scared, but after the first one, it did't bother me.

I didn't think it use needles more of a pointy thing (pencil point) that presses against your cheek or neck (didn't pierce the skin)....   it made my cheek twitch...

[Inna]

Thank you for your  response, OTO.
Inna