Evoked Potential Tests
BAER Test
The brainstem auditory evoked response (BAER) test detects how the brain processes sounds that a person hears. The BAER test measures your brainwaves in reaction to clicks or other audio tones presented to you. A brainstem auditory evoked potentials (BAEP) or auditory brainstem response (ABR) test is another name for this examination.
A BAER test may help diagnose hearing loss and nervous system disorders, especially in infants, children, and individuals who are unable to take a conventional hearing test.
for whom is the BERA test for?
Brain Evoked Response Auditory (BERA) is a hearing test for children aged 1-3 years, while younger children may undergo an OtoAcoustic Emission (OAE) test. Normal BERA results indicate typical hearing function with no need for further treatment. Abnormal results require determining the hearing threshold and starting rehabilitation, such as hearing aids, promptly. The test takes about an hour.
Why should you take the BERA Test?
BAER is used to diagnose acoustic neuroma, instrinsic brainstem lesions (e.g., multiple sclerosis, infarction, gliomas), and hearing loss.Hearing loss in youngsters is difficult to detect at first. Speech, linguistic, cognitive, social, and emotional issues may all be exacerbated by hearing loss. As a result, it is preferable to conduct a hearing test on youngsters as soon as possible.
When the auditory nerve is able to transfer sound impulses from the ear to the brain at a particular pace, this is referred to as healthy hearing. The BERA test may determine if nerves transmit sound impulses to the brain and whether sound delivery speed is within normal limits. This hearing test may identify the kind of problem (conductive or sensorineural), severity (hearing threshold), and location of the child’s hearing loss (inner ear or other regions).
When the auditory nerve is able to transfer sound impulses from the ear to the brain at a particular pace, this is referred to as healthy hearing. The BERA test may determine if nerves transmit sound impulses to the brain and whether sound delivery speed is within normal limits. This hearing test may identify the kind of problem (conductive or sensorineural), severity (hearing threshold), and location of the child’s hearing loss (inner ear or other regions).
Procedure
BERA may be performed without requiring the patient to do anything. Patients simply need to lie down, ideally calmly or while asleep. This examination may be performed on children when they are awake, asleep, or under anaesthesia (although rarely). During the BERA test, electrodes will be put on the patient’s head and behind the ear. After the assessment, the patient will be exposed to clicking sounds through headphones. This test assesses variations in brain electrical activity (EEG) in response to auditory stimulation. Hearing loss is indicated by abnormalities in the transmission of signals when sound is heard.
Somatosensory evoked potential study
The transmission of bodily sensations to the brain and how the brain perceives such feelings are studied in a somatosensory evoked potential test (SEP). An electrical signal is generated by a stimulating electrode that is placed on your arm or leg. Electrodes for recording are attached to your head and/or spine. The data collected by these electrodes may aid in the diagnosis of your condition.
how does it work
The exam determines how well your peripheral nerves and spinal cord are functioning. It also examines how your brain and/or spinal cord convey information about bodily sensations to your peripheral nerves. It may pinpoint a “signal blockage” in the relay system or the interpretative centre.
How is the SEP test performed?
You will be requested to lie down and stay completely motionless. “Recording electrodes” will be glued or taped to your head, neck, back, or legs by a technician. On your arm or leg, one or two “stimulating electrodes” are also implanted. A pulsating stimulus will begin in one of the stimulating electrodes after each electrode is examined with a metre to verify appropriate functioning. The pulsating will begin again each time a different region is checked. It will take 10 to 15 minutes to test each region.
What happens after a SEP test?
Acetone will be used to remove the electrodes, which will dissolve the adhesive while leaving your hair and skin undamaged. The test findings will be given to you either by the doctor on the day of your appointment or by a copy of the letter delivered to your personal physician.
How long does it take to complete a SEP test?
It takes around half an hour to one hour.
What is the purpose of a SEP test?
If you have numbness, muscular weakness, loss of vibration and position sensation, or symptoms after a spinal or brain injury, this is the test for you. Your muscles may tingle and twitch throughout the test, but you will not feel any discomfort.
Visual Evoked Potential Study
A visual evoked potential (VEP) or visual evoked response (VER) test examines the abnormality in the optical path from eyes to brain’s occipital lobe. It is used to see whether there is any damage to this pathway, which may be causing specific visual problems. The VEP should take around 30 minutes to complete.
Procedure
The VEP should take around 30 minutes to complete. To begin, the technician will measure the patient’s head and mark the electrode locations using a non-toxic, washable marker. These regions will subsequently be exfoliated using an exfoliating cream. A conductive lotion and cotton balls will be used to apply four electrodes.
The patient’s vision will next be tested by the doctor. If you use corrective glasses, bring them to the exam and wear them. The lights will then be turned out, and the patient will be instructed to concentrate on a dot in the centre of a black and white checkerboard screen. The checkers will move back and forth, and the patient must maintain concentration on the dot in the middle for the greatest results. Each eye will be examined several times. The test is finished when the results are properly saved and printed. An expert will evaluate the test findings, and the final report will be submitted to the physician.
When should the VEP be used?
When you are experiencing changes in your eyesight that may be caused by abnormalities along the routes of specific nerves, your doctor may advise you to get a VEP test if you have:
Loss of eyesight
Duplicate vision
Vision impairment;
Flashing lights;
Changes in colour vision;
Weakness in one’s eyes, arms, or legs.
Your face and hair should be clean and dry, with no gels, sprays, oils, makeup, or lotion on them.
Side effects associated with the VEP test are nil.
