Neurodiagnostics
Neurodiagnostic tests measure the electrical activity in your brain, nerves and muscles. This helps us assess and monitor how well your nervous system is working.
As a Center of Excellence in neurology, we use several neurodiagnostic tests to help create a comprehensive picture of your health for diagnosing neurological conditions, guiding treatment plans, and monitoring progress.
Learn more about the types of test we use, how we use them, and what to expect at your appointment with us.
There are three main tests we use to assess your nervous system and muscle activity.
- An electroencephalogram (EEG), which records brain activity
- An electromyography (EMG), which records electrical activity in your muscles
- A nerve conduction study, which measures how fast an electrical signal travels along your nerve, such as an electroneurography test (ENoG). It’s often done with an EMG
Other neurodiagnostic tests you may have are somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP). They’re similar to a nerve conduction study, except they assess how well an electrical signal travels along the nerve instead of how fast it travels.
- An SSEP tests your sensation by sending and monitoring electrical signals going from the limbs to the brain
- An MEP tests your movement by stimulating electrical signals in the brain and monitoring how the limbs respond
Another test you may have is an electrocardiogram (ECG), which is used to assess your heart health. This is not a neurodiagnostic test, but it’s a useful tool to help rule out other causes of symptoms during diagnosis, monitor your overall condition, and help plan your treatment.
Neurovestibular Assessments
Neurovestibular assessments evaluate the balance system of your inner ear and its connection with your brain. They help detect conditions such as vertigo, dizziness, imbalance, or unexplained falls, which are often linked to neurological or vestibular disorders.
Common neurovestibular tests include:
- Videonystagmography (VNG): Records eye movements to evaluate how your inner ear and brain work together to maintain balance.
- Rotational Chair Testing: Assesses your vestibular function by measuring eye responses to controlled chair movements.
- Posturography: Measures how well you can maintain balance under different conditions.
These assessments provide valuable information for diagnosing disorders such as Ménière’s disease, vestibular neuritis, or balance disturbances associated with neurological conditions like multiple sclerosis or Parkinson’s disease.
Your may have a neurodiagnostic test or ECG at several points of your journey, depending on your condition, symptoms or treatment plan.
Electroencephalogram (EEG)
An EEG is used to investigate symptoms related to the brain, such as memory problems, fainting, and seizures. It can help us diagnose, track, and learn more about your condition.
EEG is commonly used to support the diagnosis and monitoring of epilepsy. It can help your neurologist:
- Determine what type of epilepsy you have
- Identify potential seizure triggers
- Design an effective treatment plan for you
Other conditions you may have an EEG for include dementia, brain injuries and concussions, and swelling in the brain.
Electrocardiogram (ECG)
An ECG measures your heart activity. This can help monitor your health and diagnose and plan treatment for a range of neurological conditions. You may have one to:
- Rule out cardiac causes for symptoms such as fainting, dizziness, or seizures
- Make sure you’re well enough for certain treatments, especially if you already have a heart condition
Electromyography (EMG) and nerve conduction study
You may have an EMG or nerve conduction study if your symptoms are related to your nerves or muscles, such as muscle weakness, numbness, or tingling. It’s an important diagnostic tool for neuromuscular conditions including:
- Injured or compressed nerves
- Neuropathy
- Motor neuron disease
- Myasthenia gravis
Each test is slightly different. Your neurologist will explain how to prepare for your test, what to expect, and answer any questions.
EEG
Your neurologist will let you know if you need to prepare for your EEG, but most people do not need to. It’s helpful to have clean and dry hair without any hair products for your appointment, such as hairspray or wax. This helps the sensors stick to your scalp.
A specialist called a neurophysiologist performs your test. They’ll use a special glue to attach small sensors to your scalp. The sensors are connected to an EEG recording machine. During the test, they may ask you to do some tasks, such as deep breathing, blinking, or looking at a flashing light.
Your test will take around 20 to 40 minutes, but the entire appointment may be up to an hour. If you have no other appointments at the center, you’re free to leave once your test is over.
When your results are ready, your neurologist will schedule an appointment with you to discuss them in-person and plan any next steps.
A sleep deprived EEG
A sleep deprived EEG is sometimes carried out to assess epilepsy or seizures. It’s the same as a regular EEG, but the lack of sleep can help reveal unusual brain activity.
If you’re having an EEG with sleep deprivation, you’ll need to stay awake the night before your test. If that isn’t possible, you can sleep for up to four hours. Your neurologist will advise you on this and anything else you may need to do to prepare.
ECG
There are some things you can do in advance to help your ECG go smoothly, such as:
- Wearing loose and comfortable clothing that’s easy to move in
- Avoid using any products on your skin, such as lotions, oils, and powders, as they can interfere with the reading
- Avoid eating a large meal or drinking caffeine just before your test
During your test, a specialist clinician attaches sticky sensors to your chest and sometimes to your arms and legs. The ECG machine next to you records your heart activity for a few minutes. Once it’s done, we remove the sensors and you can leave as soon as you’re ready.
Removing the sensors may feel slightly uncomfortable and leave some redness or a rash behind. This will go away shortly.
Your results may be ready on the same day. Your neurologist will meet with you to discuss the results and explain next steps.
EMG and nerve conduction study
Your neurologist will speak to you before the test if you have a pacemaker or other implanted device, and if you take any blood thinning medication. Generally, before your test you should:
- Take off any jewelry, such as bracelets, watches, rings, and necklaces
- Wear loose, comfortable clothing so your arms and legs can be easily tested
- Avoid using skin products on your arms and legs, such as lotions, oils, and powders
- Keep your hands and feet warm, as cold skin can affect your results
Your test is performed by a neurophysiologist and can take around 30 minutes. It’s split into two parts: the nerve conduction study and the EMG, though not everyone will need the EMG.
Nerve conduction study and EMG steps
- Your neurophysiologist will attach sticky sensors to your body. This might include your arms, legs, face, shoulder, or chest.
- For the nerve conduction study, we use small electrical pulses to stimulate your nerves. This will feel like a tapping or tingling sensation and can cause your muscles to twitch.
- If you do not need an EMG, you can go home straight away.
- If you need an EMG, your neurologist will put a very fine needle into your muscle to record the electrical activity at rest and when you use it. The needle is very small and should not cause much discomfort.
- After your test, you can go home. If you had your chest tested, you may need to stay for an extra 30 minutes for observation.
Your results should be ready within two days. Your neurologist will arrange an appointment to discuss them with you and plan any next steps.
Potential side effects
Our experienced neurologists will perform your test to an extremely high standard to minimize risks. Before you go, we’ll make sure you’re feeling well and explain what to look out for after you leave.
It’s normal to have some soreness and bruising where you had your EMG test. This is normal and should pass after a few days.
If your chest was tested during your EMG, there is a very small risk of pneumothorax. This is where air leaks out of the lung and into the chest cavity. This is very rare.
We surround our patients with specialists who listen, understand, and care. They include some of Europe's most renowned experts – neurologists,
neuropsychologists, neuroradiographers, microbiologists, nurses, nuclear medicine experts and therapeutic specialists in physiology and occupational health.
