NEUROPHYSIOLOGY

1. Electroencephalogram (EEG)

An electroencephalogram (EEG) is a safe, painless, and noninvasive test that records the electrical activity of the brain using small sensors (electrodes) attached to the scalp. It is primarily used to diagnose epilepsy, sleep disorders, brain injuries, and tumors.

Why an EEG is Performed:

• Epilepsy Diagnosis: Identifying seizures.
• Sleep Disorders: Diagnosing narcolepsy or sleep apnea.
• Other Brain Conditions: Assessing encephalitis, tumors, memory loss, dementia, or coma.

2. Nerve Conduction Studies

A nerve conduction velocity (NCV) test measures how fast an electrical impulse moves through your nerve. NCV can identify nerve damage.

NCV is often used along with an EMG to tell the difference between a nerve disorder and a muscle disorder.

Diseases or Health Problems Checked with NCV:

• Guillain-Barré Syndrome: The immune system attacks part of the peripheral nervous system.
• Carpal Tunnel Syndrome: Compression of the median nerve causing pain and numbness.
• Charcot-Marie-Tooth Disease: An inherited neurological condition affecting motor and sensory nerves.
• Herniated Disk Disease: Pressure on spinal nerves causing pain and nerve damage.
• Nerve Damage (Neuropathy): Can result from diabetes, chemotherapy, autoimmune disorders, or alcoholism.
• Sciatic Nerve Problems: Often caused by a bulging or ruptured spinal disk.

3. Electromyography (EMG)

Electromyography (EMG) measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle.

During the test, one or more small needles (electrodes) are inserted into the muscle to measure electrical activity.

Conditions Diagnosed:

• Carpal tunnel syndrome
• Pinched nerves and radiculopathy
• ALS (Amyotrophic Lateral Sclerosis)
• Muscular dystrophy
• Myasthenia gravis

4. Sleep Study (Polysomnogram)

A sleep study, or polysomnogram, is a painless overnight diagnostic test that records brain activity, eye movement, heart rate, breathing, and oxygen levels.

It is used to diagnose disorders such as sleep apnea, narcolepsy, insomnia, and parasomnias.

Conditions Diagnosed:

• Obstructive sleep apnea
• Restless leg syndrome
• Parasomnias (such as sleepwalking)
• Narcolepsy