Neuropsychology Services
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Neuropsychology Services
96 W. Main Street, Northboro MA
tele: 508-393-3820
fax: 508-393-3814
NEUROPSYCHOLOGY_SERVICES@YAHOO.COM
Traumatic Brain Injury
[Dr. Deckel worked early in his career as an intern at the New England Spinal Cord Unit in Boston. Later, as the Director of the Neuropsychology Service at the University of Medicine and Dentistry of New Jersey (Newark) he extensively taught and conducted research into the causes and effects of head injury. He also served for two years as the inpatient Neuropsychologist at the Kessler Institute Brain Trauma Unit in E. Orange, N.J. Over the course of his career he has evaluated and treated a very large number of individuals with traumatically induced head injury and worked with people with brain injury from a multitude of causes. Now in private practice, he is available by appointment to provide neuropsychological evaluations for people with TBI. He also is available for individual consultation. Dr. Deckel's neuropsychological evaluations frequently are used as a first step in constructing a meaningful outpatient program of brain-injury rehabilitaiton for a person with a TBI. ]
There are multiple forces that act on a brain when someone strikes their head in a car accident, experiences a fall., or suffers a traumatic brain injury In fact, any time the head is rapidly rotated backwards or forwards damage to the brain can occur. This rotation can be caused by the head snapping back and forth (i.e., when someone is shaken), from a rapidly moving head suddenly stopping (i.e., when a head strikes a dashboard) or from when the head is suddenly accelerated (i.e., when some rapidly moving object, like a baseball bat, strikes a stationary skull). Because of a series of tough membranes that hold the head, the damage is usually worse when the head rotates forwards and backwards as the membranes in the head (called the meninges) allow such movement. Conversely, little rotation "left to right" is allowed by the meninges so little damage occurs from the head shaking left-to-right.
There can be primary damage to the brain, or secondary damage, following injury to the head. Primary damage can include direct brain tissue damage from penetrations into the brain, such as when a sharp object penetrates the skull and enters the brain. Direct brain damage can also be caused by tearing of blood vessels and bleeding into the brain. Direct damage also can occur because of anxonal shearing, also known as diffuse axonal injury (described further below). Finally, the "kinetic energy" from the brain rapidly moving forwares and backwards is often translated into a deep regions of the brain, called the brainstem. This energy causes the so-called "coup-countracoup" injuries, where front and rear regions of the brain literally bounce off the bony substance of the skull and get injured because of this. These last two injuries are illustrated in the picture below.
Secondary brain damage refers to the other injuries to the brain that result from the above events. For example, torn blood vessels can lead to decreased oxygen to the brain. This, in turn, can lead to an increase in the release of the neuro-chemical called glutamate, which in turn can casue a series of brain injuries.
DIFFUSE AXONAL INJURY/AXONAL SHEARING
The brain is made up of many millions of brain cells. Most brain cells connect to other brain cells by sending a long thin membrane out to connect to other brain cells. This long thin projection is called an axon.
This picture is taken from: http://catalog.nucleusinc.com/
displaymonograph.php?MID=12
UNDERSTANDING WHAT AN AXON IS:
In this picture, you can see that a nerve cell is made up of several parts. These include a cell body (where the nucleus of the cell is found) and an axon that, in this picture, is covered with a white substance called myelin. Some axons are covered with myelin, some are not. The so-called "white matter" of the brain is made up of millions of myelin covered axons coursing through the brain.
This picture is taken from: http://catalog.nucleusinc.com/
displaymonograph.php?MID=12
WHIPLASH AND COUP/COUNTERCOUP INJURY:
This picture shows how a rapid rotation of the head can lead to extreme stresses on the deep part of the brain, called the brain stem. It also shows how axonal shearing can happen when this rotation "stretches" the axons, which are connecting the various different nerve cells to one another. Finally, it illustrates how the rapid rotation of the brain can lead to a "bouncing" of the brain tissue (shown in red) off the various different bony structures of the skull. Any and all of these effects may contribute to the brain injury that results from TBI
When the brain is suddenly and violent moved forwards or backwards, there can be a great deal of strain put on the axons that are going from the very topmost regions of the brain down and out the brainstem. This is described in greater detail in the following link: http://en.wikipedia.org/wiki/Diffuse_axonal_injury#Characteristics.
Take a look at the whiplash figure above--it is not hard to imagine how that injury would literally tug on the axon connections and injure them. With today's imaging technologies we can actually "see" these injuries. On traditional MRI scans they can look like small white matter lesions, causing your neurologist to wonder if you have a so-called demyelinating disease instead of realizing that head injury can cause these changes. On a very sophisticated technique called tensor diffusion imaging one actually can see that the flow of water from the cell body of the nerve cell through the axon is disturbed following brain injury, this because of diffuse axonal injury. Diffuse axonal injuries can also cause profound subtle changes inside the cell. Calcium, a vitally important substance in the nerve cell, is fundamentally altered following diffuse axonal injury, as described in the articles provided by the following link: http://www.experiencefestival.com/diffuse_axonal_injury_-_calcium_influx. This alteration in calcium can damage and, in some cases, kill the affected nerve cells.
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Brain Injury, Traumatic Brain Injury, TBI, and Head Injury here to add t
