What is Neurodiagnostics?

An electroencephalogram measures the electrical activity of the brain. Using an internationally recognized method of identifying and placing electrodes on the surface of the scalp, the technologist will then monitor brain activity to observe possible abnormal waveforms arising from the brain. The EEG is used to look for seizures and other dysfunction of the brain.

EMG (Electromyography) and NCS (Nerve Conduction Studies) are complimentary tests. The NCS is used to determine the health of peripheral nerves. The Neurodiagnostic Technologist does this by using a device held to the skin to stimulate nerves with a controlled electrical pulse. The speed and strength that the pulse travels through the nerves is measured. For the EMG, a physician inserts a special needle designed to detect the electrical activity produced by muscles. The signal produced is evaluated to determine the health of the muscle and the nerve. The information from the NCS and EMG is used as an extension of the physical examination to diagnose a wide array of neuromuscular diseases, degenerative disorders, and injuries related to the nerves and muscles such as carpal tunnel syndrome, neuropathy, and ALS.

Intraoperative Neuromonitoring is used to assess the integrity of neural structures continuously throughout surgical procedures. IONM uses a variety of neurodiagnostic modalities to aid in these procedures including evoked potentials, EEG, and EMG. They play an invaluable role in the surgical team as they are able to detect warning signs through testing that may prevent neurological damage or paralysis.

Transcranial Doppler is a form of ultrasonography that measures blood flow within and to the brain. TCD uses high-frequency sound waves to detect the direction and velocity of blood flow. This testing is useful to indicate narrowed or blocked vessels in patients with issues such as Sickle Cell Anemia or brain aneurysms that could put them at risk for having a stroke.

An Evoked Potential provides information on the electrophysiologic response from different types of stimuli.  There are three types of evoked potentials performed by Neurodiagnostic Technologists including Visual Evoked Potentials (VEP), Brainstem Auditory Evoked Potentials (BAEP), and Somatosensory Evoked Potentials (SSEP). A VEP tests the visual pathway to the occipital cortex which can show optic nerve lesions or disturbances.. A BAEP assesses the auditory pathway in the brainstem which can identify hearing loss in patients who are sedated, too young, or otherwise unable to respond.. The SSEP is able to detect damage in the brain and spinal cord by measuring signals from the peripheral nerves to the brain.

Autonomic testing assesses how the Autonomic Nervous System (ANS) functions and responds to stimulation. The ANS is responsible for body functions that occur automatically such as breathing, body temperature, heart rate, and blood pressure. Autonomics plays a key role in detecting problems such as Parkinson's Disease, autonomic or small fiber neuropathies, and Postural Orthostatic Tachycardia Syndrome (POTS). 

Magnetoencephalography measures the magnetic fields produced by the electrical currents in the brain. MEG uses a device called SQUID (superconducting quantum interference device) to detect tiny magnetic fields and produce images to localize where seizures and other brain functions originate. 

Polysomnography, commonly referred to as sleep studies, evaluate sleeping disorders. Electrodes and other devices are placed on the body and are used to detect heart rate, breathing, oxygen levels, and brain waves. PSG is able to monitor for sleep apnea, narcolepsy, and other sleep-related disorders.