This test is used to examine the function of the optic nerve, which carries messages from the eye to the brain.  It is a painless procedure.  Small metal discs are placed on the scalp.  The patient is then asked to look at a tv screen, which has black and white squares that move.  The patient is asked to focus on the center of the tv screen.  Each eye is tested separately, with the eye not being examined covered with a square piece of gauze.  Each eye is examined at least twice.  The examination takes about 30 minutes to complete.  With young children, cartoon characters are placed in front of the monitor to draw their attention.

This test is similar to test (1) above.  However, it specifically examines the part of the optic pathway that is called the optic tract that exists towards the back of the head, and is responsible for looking at specific parts of the visual field, such as the left or right side.  Recording is similar, but the tv screen has black and squares on one half of the screen.  This examination takes a little longer than (1) above as it is more detailed, about one hour.

This test is used to rule out blindness.  It is a painless procedure.  It is used in infants and young children that cannot cooperate for test (1) above.  A flashing light is presented to each eye separately using special goggles.  Depending on the results, the examiner can decide whether the patient can receive light signals.  The examination takes about 30 minutes to complete.

This test is used to examine the function of the retina of the eye, the part of the eye that converts light into electrical signals that the brain can understand, and leads to the sensation of vision.  It is a painless procedure.  Small metal discs are placed on the scalp.  The patient is then asked to look at a tv screen, which has black and white squares that move.  The patient is asked to focus on the center of the tv screen.  Both eyes are tested together.  The examination takes about 30 minutes to complete.

This test is used to examine the function of the retina of the eye, the part of the eye that converts light into electrical signals that the brain can understand, and leads to the sensation of vision.  Specifically the cells of the retina responsible for vision in the dark and light respectively are tested.  It is a painless procedure.  Small metal discs are placed on the scalp.  The patient is asked to look inside a dome with flashing white light.  The light is presented at different intensities and flash frequencies, with a part of the test performed with the lights off, and the remaining examination performed with the lights off.  The examination takes about one hour to complete.

This test is used to examine the function of the cochlear nerve of the ear, the nerve responsible for the sensation of hearing.  Because this examination is able to record the path of the signals relating to hearing up to a specific part of the brain, this examination is also used to monitor function in a part of the brain called the brainstem, located at the base of the brain.  It is a painless procedure.  Small metal discs are placed on the scalp.  Earphones are placed over the ears, and the patient listens to certain sounds.  The examination takes about 30 minutes to complete.

The bone-conducted BAEP procedure is usually performed in patients, especially children, with aural malformations.It is similar to (6).  The examination takes about 30 minutes to an hour to complete.

This test is similar to (6) above in its technique, but specifically is used to determine hearing threshold, the intensity level where the patient can barely hear the clicks.  It is a painless procedure.  Small metal discs are placed on the scalp.  Earphones are placed over the ears, and the patient listens to certain sounds.  The intensity of the sound is decreased gradually.  This examination is useful for young children that cannot cooperate for standard audiometry examinations.  The examination takes about 30 minutes to complete.

This test is used to examine the vestibular nerve of the ear, the nerve that is responsible for the sensation of balance. It is a painless procedure.  Small metal discs are placed on the neck. Earphones are placed over the ears, and the patient listens to certain sounds.  While the patient is lying down s/he is asked to lift her/his head slightly from the pillow.  The examination takes about 30 minutes to complete.

This test is used to test the part of the spinal cord and brain that is related to the sensation of touch, pressure and vibration sense, more specifically the back region of the spinal cord and somatosensory cortex (the part of the brain that receives and gives messages for sense and movement).  Small metal discs are placed on the scalp, shoulder area, and back.  Using a low intensity electrical stimulus, specific nerves are stimulated either at the wrist or ankle.  The test takes between 30 minutes and an hour to perform.

Dermatomes are related to SSEPs, where electrical stimuli is measured at the surface of the scalp. The main difference between SSEPs and dermatomal recordings is that a skin surface is stimulated at a lower electrical current than what would be used to stimulate a nerve. The skin surface that is stimulated is innervated by a particular nerve root from the spine. Dermatomes are useful because they are specific for a particular nerve root whereas SSEPs are used for measuring general upper and lower body nerve activity and velocity.  The test takes about 30 minutes to perform.

This test is used to examine the motor pathways of the central nervous system, the part that is involved in ordering and controlling muscle movements.  It is a painless procedure.  Small metal discs are placed over the muscle we wish to examine.  A magnet is then used as the stimulator and placed over the scalp and over the back.  The test takes 30 minutes to perform, depending on which muscles we wish to examine.

13)   Routine Electroencephalography (REEG)

This test is used to record the general function of the brain in real time.  The test is not painful.  Small metal discs with conductive cream are placed on the scalp at about 20-25 specific places.  The patient then lies down and 20 minutes of recording is obtained.  The patient may be asked during the recording to perform three minutes of heavy breathing, and the patient may also be asked to look at some flashing white light at different frequencies.  The total test time is approximately one hour.

This test is a modification of test (15) above, with simultaneous video recording.  Recording is performed long-term in the neurology ward, from several days to a few weeks.  The patient will stay overnight in the ward for as long as his doctor deems it necessary.

This test is used to examine sleep.  Surface electrodes are used to record electroencephalography (brain function), muscle activity, airflow through the nose and mouth, movements of the chest and belly during breathing, electrocardiography, blood oxygen levels and body position.  The study is performed overnight in the neurology ward.  Before the exam, the patient fills in a sleep questionnaire, which documents the patient’s sleep habits and symptoms, such as snoring and waking up in the middle of the night.

This test is similar to (17) above, but is performed during the day, and the patient is allowed to take 5 naps lasting 20 minutes each, with about 1.5 hours in-between.  It is used to investigate excessive daytime sleepiness.

Vagus Nerve Stimulation (VNS) is used as an adjunctive therapy in reducing the frequency of seizures that are refractory to anti-epileptic medications.  The patient is implanted with the VNS device, which delivers electrical signals to the brain via the vagus nerve (accessible from the neck).  Programming of the device and monitoring of the patient takes place at CING.

Intra-operative monitoring is a service that is provided by the Neurophysiology department.  Intra-operative monitring has been done in brain surgeries for epilepsy.  Intra-operative monitoring is done for vagal nerve stimulator surgery routinely.