Testing for Neurological Conditions

An EMG is a recording of your muscles at rest and during activity. It’s used to assess the health of your muscles and the nerve cells that control them. You should avoid wearing creams or lotions on the day of the test.

The EMG is a one-hour procedure where the physician will clean the testing area and then insert a small needle, called an electrode, into the muscle tissue. When the muscles contract, the electrode detects electrical activity. A computer attached to the electrode displays and records the signals for further analysis. The pattern and characteristics of these signals provide valuable information about the health of your muscles and nerves.

You may feel some pain or discomfort during the EMG test. Most people can complete the procedure without any problem. You may experience some bruising and tenderness in the affected area after the test.

EMG is used to detect neuromuscular diseases, motor issues, injuries or degenerative conditions, such as:

• Amyotrophic Lateral Sclerosis (ALS)
• Spinomuscular atrophy
• Myopathy
• Carpal tunnel syndrome
• Herniated disks
• Spinal stenosis
• Guillain-Barré Syndrome (GBS)
• Muscular dystrophy
• Neuropathy

A nerve conduction study is a neurological test to identify any damage to your peripheral nervous system — the nerves located outside your brain and spinal cord that extend to the rest of the body.

An NCS is used to study how well your nerves transmit signals to the muscles and sensory organs in the body.

Your doctor may recommend an NCS if you experience tingling or numbness in your arms, legs or face. These studies are often performed alongside an EMG. An EMG measures your muscles’ reaction to signals from a nerve, while an NCS measures how well a signal moves through the nerves.

During a nerve conduction study, a technician will place electrodes on your skin to apply a small electrical stimulus and record the nerve’s electrical response. You should avoid wearing creams or lotions on the day of the test. Testing usually takes one hour and is non-invasive.

Two types of NCS that measure the flow of electrical current in your peripheral nerves include:

• Motor NCS: Used to evaluate the function of motor nerves that control muscle movement.
• Sensory NCS: Used to assess the function of sensory nerves that transmit sensations like touch and temperature.

Nerve conduction studies are commonly used to diagnose neurological disorders, such as:

• Peripheral neuropathy
• Carpal tunnel syndrome
• Ulnar neuropathy (like a nerve compression at the elbow)
• Radiculopathy
• Other conditions affecting the peripheral nerves

Autonomic testing is a neurological test to assess your autonomic nervous system (ANS) — the involuntary system that controls your bodily functions, such as heart rate, blood pressure, digestion and breathing. The tests will vary depending on your symptoms. You should avoid wearing creams or lotions on the day of the test. Testing usually takes 1-2 hours and is non-invasive and painless.

Common types of autonomic testing include the following:

• Heart rate variability (HRV) testing: Measures any variation between consecutive heartbeats.
• Tilt table testing: Monitors any heart rate and blood pressure changes in response to changing your body’s position on a tilting table.
• Sweat testing: Evaluates your sweat glands’ ability to respond to stimuli.
• Quantitative sudomotor axon reflex test (QSART): Measures the nerves that control your sweat.
• Valsalva maneuver: Measures your body’s response to deep breathing and forcefully breathing out.

If you are experiencing an issue with the nerves that sense pain and temperature, your physician may conduct a biopsy of the affected area.

The procedure involves removing a small piece of skin, under local anesthesia. The sample is then processed and examined under a microscope to assess the density and structure of nerve fibers.

A skin biopsy is not typically the first-line test for neurological disorders. It is usually reserved for cases where other diagnostic methods don’t provide a clear diagnosis and where small fiber neuropathy (SFN) is suspected. Symptoms of SFN included burning, tingling or numbness.

Small fiber neuropathy can be genetic or caused medical conditions like diabetes and thyroid disease.

Your provider may order a neuromuscular ultrasound (NMUS) as a complementary test to an EMG or other neuromuscular testing. An ultrasound is a diagnostic imaging tool that allows the team to visualize your peripheral nerves and muscles in real time. The test improves the accuracy of other neuromuscular testing.

A NMUS is a non-invasive test where a technician will place a cool gel on the affected area. The specialist will gently move a probe tool over your skin to take images of your nerves and muscles. You should avoid wearing creams or lotions on the day of the test.

Ultrasounds are commonly used to diagnose neurological disorders, such as:

• Carpal Tunnel Syndrome
• Chronic Inflammatory Demyelinating Polyneuropathy
• Lumbosacral Plexopathies
• Muscular Dystrophies and Related Disorders
• Myositis
• Neuropathy
• Sciatica
• Small Fiber Neuropathy
• Ulnar Neuropathy

Evoked potential tests measure how quickly your brain, spinal cord or nerves respond to stimulation. Testing usually takes one hour and is non-invasive. You should avoid wearing creams or lotions on the day of the test.

Your technician will clean the testing area and then attach small electrodes on your scalp or skin. The tests help assess the function of the nervous system and can sense damage along nerve and brain pathways that cannot be detected in a neurological exam.

There are three different types of evoked potential tests, including:

• Visual evoked potentials (VEP) to measure electrical signals your visual cortex generates in response to images and light.
• Auditory evoked potentials (AEP or BAEP) to measure electrical signals your auditory pathways generate in response to sound.
• Somatosensory evoked potentials (SEP) to measure activity your sensory cortex (brain) generates in response to stimulation of the skin. This is often used to detect damage to the spinal cord or brain.

Evoked potential tests are typically used together with other diagnostic tools.

These tests are used to diagnose neuromuscular issues such as:

• Nerve damage
• Multiple sclerosis
• Hearing screenings
• Spinal cord injuries

An EEG measures your brain’s electrical activity as a series of squiggles called traces. Each trace corresponds to a different region in your brain. Certain abnormal patterns, such as spiking and sharp wave activities on an EEG, can help support or confirm a clinical diagnosis of epilepsy.

There are two kinds of outpatient EEG tests, a test performed in the clinic and an ambulatory test performed at home. Both tests are safe and painless. You should avoid wearing creams or lotions on the day of the test. Your neurologist will determine which test is right for you.

Outpatient EEG in the clinic

This EEG is about an hour-long test in a clinical setting. You will be asked to relax in a bed with the lights turned low. The technologist will clean your scalp and attach small metal cup-shaped disks called electrodes to your head with water-soluble paste. The electrodes will record your brain’s electrical signals. You will need to lie still throughout the test so that the electrodes don’t pick up on any other movement. The technologist may show you flashing lights.

Ambulatory test

In an ambulatory EEG, you’ll be fitted for a portable EEG device that continuously monitors and records your brain’s electrical activity while you engage in usual activities. Electrodes are secured to the scalp with glue and wrapped in gauze for up to four days. The device is designed to be portable, lightweight and non-intrusive. You may be asked to record any episodes in a diary as well.

An EEG is a valuable tool to diagnose neurological disorders such as:

• Epilepsy
• Sleep disorders
• Cognitive disorders

If you experience persistent seizures, the Epilepsy Monitoring Unit (EMU) can be used to identify the type of seizures you have, where they originate and determine if you are a potential candidate for surgery. This inpatient EMU evaluation allows your provider to monitor seizures or other brain events. The information gathered in the EMU will assist our experts in accurately diagnosing your condition and finding the best treatment plan for you.

While in the EMU, you will be connected to continuous video EEG and closely monitored by the EMU team. In this controlled environment, your doctor may adjust your medication dosage or use different strategies to trigger an event. Our dedicated EMU team will provide 24/7 monitoring throughout the evaluation.