What is an EEG?

• An Electroencephalogram (EEG) is a non-invasive diagnostic test that measures and records the electrical activity of the brain. By using small, flat metal discs called electrodes attached to the scalp, EEG captures electrical impulses moving through the brain. These impulses are the result of neuronal activity and are crucial for diagnosing various neurological conditions.

How is an EEG performed?

• During an EEG, electrodes are adhered to specific locations on the scalp using a special paste or cap. The electrodes are connected to a machine that records the brain’s electrical activity. During the test, patients may be asked to perform simple tasks, such as breathing deeply or looking at specific patterns, which can provoke brain responses. The test typically lasts about 60 minutes, but can vary depending on the specific protocols being followed.

What can patients expect during an EEG?

• Patients undergoing an EEG can expect a painless procedure. They will be seated or asked to lie down in a comfortable position. To provoke brain activity changes, they might be exposed to various stimuli, including light flashes or auditory signals. It's important for patients to remain still and minimize eye movements during the test to ensure accurate results. In some cases, an EEG may be performed while the patient is asleep or during a sleep-deprived state.

How to prepare for an EEG?

• Wash your hair: Clean hair free of oils, sprays, and conditioners ensures better adhesion of the electrodes.
• Avoid caffeine: Patients should avoid caffeine for at least 8 hours before the test, as it can affect the results.
• Get a good night’s sleep: Unless instructed to be sleep-deprived for the EEG, a good night’s sleep helps ensure a smoother testing process.
• Wear comfortable clothing: This helps you relax during the test, as you might be sitting or lying down for a prolonged period.

What is an EEG used for?

EEGs are critical in diagnosing and managing several neurological conditions, including:

• Epilepsy and Seizure Disorders: EEGs can identify abnormal electrical activity that signifies different types of seizures.
• Brain Tumors, Stroke, and Brain Damage: EEGs help assess the impact and extent of brain damage.
• Sleep Disorders: They can diagnose conditions like sleep apnea, narcolepsy, and sleep-related seizures.

What is an EMG?

• Electromyography (EMG) is a diagnostic procedure that assesses the health of muscles and the nerve cells that control them (motor neurons). Motor neurons transmit electrical signals that cause muscles to contract. An EMG translates these signals into graphs, sounds, or numerical values that a specialist interprets.

How is an EMG performed?

• During an EMG, a needle electrode is inserted through the skin into the muscle tissue. This electrode picks up the electrical activity generated by muscle fibers. The electrical activity is displayed on a monitor, and the specialist evaluates the signals both when the muscle is at rest and during slight and forceful muscle contractions. The test can help diagnose conditions that affect muscle tissue, nerves, or the junctions between nerve and muscle, such as:
• Muscular dystrophies
• Inflammatory myopathies
• Peripheral neuropathies
• Radiculopathies

What are Nerve Conduction Studies (NCS)?

• Nerve Conduction Studies (NCS) measure how well and how fast nerves can send electrical signals. This test is often done alongside an EMG.

How is an NCS performed?

• During an NCS, small electrodes are placed on the skin over the nerve being tested. A small electrical impulse is sent through the nerve, and the response is recorded by other electrodes. The speed and strength of the nerve signal are measured, which helps in diagnosing nerve damage or dysfunction.

Conditions Diagnosed by EMG/NCS:

EMG and NCS are critical for diagnosing various neuromuscular disorders, including:

• Carpal Tunnel Syndrome: Compression of the median nerve causing pain and numbness in the hand.
• Peripheral Neuropathies: Damage to the peripheral nerves resulting in weakness, numbness, and pain, usually in the hands and feet.
• Radiculopathies: Pinched nerves in the spine causing pain, numbness, or weakness radiating into the arms or legs.
• Muscular Dystrophies: Group of diseases causing progressive weakness and loss of muscle mass.
• Myopathies: Diseases of the muscle tissue, often causing muscle weakness.