What is Neurophysiology?
Neurophysiology is a branch of physiology that focuses on the study of the central nervous system (CNS). While physiology is the broad study of the mechanisms of how cells, muscles and organs work together and how they interact, neurophysiology is much narrower.
A short history lesson may be useful to put neurophysiology into perspective. The subject has been studied for thousands of years. For example, Hippocrates studied it, in part in conjunction with epilepsy. He correctly determined that epilepsy had its origin in the brain. He also theorized that the brain was involved in all types of bodily sensation. Jumping ahead several thousand years, Galen theorized that human thought occurred in the brain. He was right, too. Thereafter, many other scientists conjectured and determined that the brain was the prime mover in virtually all aspects of the human condition.
One of the main diagnostic tools used in neurophysiology is electroencephalography (EEG). The original tool, while later refined and augmented by other tools, was originally developed in 1929 by German psychiatrist, Hans Berger. It was a milestone in the development of neuroscience and in the practice of neurology, particularly related to epilepsy.
In general, the EEG is a direct measure of electrical energies in the brain. It is usually recorded at the scalp surface and reflects the moment-to-moment electrical activity of the brain. The electrical activity is produced by the synaptic currents that arise on the dendrites and cell bodies of billions of cortical cells that are usually only a few centimeters below the scalp. It can also be a measure of damage of electrical networks in the brain that are disturbed by traumatic brain injuries (TBI). The most consistent findings in this regard are:
• Reduced power in the higher frequency bands (8-49 Hz) which is directly related to the degree of injury to cortical gray matter of the brain. The gray matter routes sensory or motor stimuli to the central nervous system to create a response to the stimulus through chemical synaptic activity;
• Increased slow waves in the delta frequency bands (1-4 Hz) occurs in the more severe cases of TBI. This is directly related to the magnitude of damage to the cerebral white matter as the increase in delta waves are often associated with, inter alia, certain neurological disorders;
• Changes in delta frequency bands and EEG phase delays that are directly related to both the gray and the white matter, especially when the temporal and frontal lobes are involved.
Clinical and validation studies performed on EEG results have shown a high correlation between them and clinical measures such as neuropsychological test performance, Glasgow coma scores, length of coma and MRI biophysical measures .
There are several other tests that are associated with the field of neurophysiology. These include:
• Nerve conduction study: Measures electrical signals in the nerves, primarily in the arms and legs. Small electrical shocks are administered to the skin over the nerve. It is typically done to determine if there is damage to the peripheral nervous system, that includes all nerves that lead away from the brain and spinal cord and the smaller nerves that branch out from the main nerves;
• Electromyogram (EMG): Measures the activity of muscles while at rest and while contracted and in so doing, measured how fast the nerves send electrical messages to the brain. While the test does not show brain or spinal cord disease, it is useful in finding the cause of paralysis or weakness, or diseases of muscles, nerves or the junction of them.
When the brain, its constituent parts and those parts of the body that directly and indirectly interact with it work and connect properly, generally all is well. However, when traumatic brain injuries, spinal cord injuries, strokes and various other difficult and challenging diagnoses arise after acute intervention, neurobehavioral and specialized neurorehabilitative services and other clinically relevant types of care are needed to restore the independence of the client. These can include post-acute care, residential services or assistance with supported living.
NeuLife, in Mount Dora, Florida, is a fully accessible residential post-acute program providing superior care and specialized rehabilitation to individuals diagnosed with traumatic brain injury (TBI), spinal cord injury (SCI), traumatic amputations and other catastrophic injuries.
2725 Robie Avenue
Mount Dora, Florida 32757
Call: 800.626.3836
Email: [email protected]
Visit: NeuLifeRehab.com
