Brain Injury Lawyers: Neuroanatomy
Neuroanatomy is an almost impossible topic to discuss in its entirety. To serve the topic justice, it would take volumes of writings. Moreover, once the volumes were written, they would virtually be out of date given our ever expanding knowledge of the topic matter. Given this, only a basic, cursory attempt is herein made to cover this bewildering subject.
The philosophers of Hippocrates’ era long wrote in acknowledgment that the organ that is our brain is the source of who we are. Our pleasure, communication, sarcasm, grief, hurt, and pain all emanate from our brain. It is our source of meta cognition, a recognizing of who we are as human beings. Through the brain we are able to taste, sense, smell, hear and think.
Arguably, the human brain is the most complex structure in the universe. So complex is it, that there are probably more things about it of which we are unaware, than those about which we know with certainty.
The relationship between the brain and behavior is an even more difficult topic to grasp. We understand enough to know that the reason for a given event is not limited to activity within a particular cortical region. Although we can speak generally about certain areas of the brain having control over certain functions, to paint in such terms is to paint with an extremely broad brush. Any given behavior is the product of a myriad of complex neurophysiological and biomechanical interactions involving the whole brain. Yet an injury focal to one area of the brain can completely disrupt one type of activity, even though different areas of the brain demonstratively control the particular activity in question.
In order to fully understand neuroanatomy, and traumatic brain injury, we must first examine the skull, or casing holding the brain. As we know, the skull is a closed bony container encasing the brain. When we refer to the skull as “closed”, we do so with the understanding that as newly born, our skulls are not “closed”. The fontanel refers to the two soft spots on a baby’s skull at birth. Fontanelles enable the soft bony plates of the skull to flex during birth in order the head passes through the birth canal. Fontanelles are usually completely hardened by a child’s second birthday, and will eventually form the sutures of the neuro cranium.
Once the fontanelles harden, the skull protects the brain from the general traumas of routine life. A common mistaken conception, however, is that the inside of the skull is smooth. Far from it, the inside of the skull is comprised of numerous bony protuberances. These sharp-edged ridges are located in close proximity to nerve tissue and blood vessels, especially near the frontal lobes. When the brain collides with these protuberances during trauma, a primary brain injury can easily occur.
Secondary damage to the brain can thereafter occur due to the progress of physiological processes of a destructive nature. Intracranial pressure, brain swelling/edema, hypoxia/ischemia, fever and infection are all secondary complications that may be set in process at the time of the primary injury leading to secondary damage of the brain.
The brain, often mistakenly referred to as having the texture of Jell-O, weighs approximately 3 pounds. In fact, the strata of the brain are of different density levels. Due to the difference in density, and the fact that specialized nerve cells called neurons transect different layers of the brain, when trauma occurs, diffuse axonal injury may occur. A neuron consists of the cell body and extending “transmittal pathway” called axons and dendrites. When the axons and dendrites transect multiple layers of the brain, and where the layers of the brain are of different density, and the brain is subjected to a sudden acceleration/deceleration movement, a shearing of the axons and dendrites occurs when the layers of the brain move at different speeds. This process is referred to as “diffuse axonal injury”, or DAI. Angular acceleration, or rotational forces are generally thought to be much more influential in resulting DAI.
Other types of events likewise cause traumatic brain injury. For example, penetrating head injuries occur when an object literally penetrates the skull into the brain itself. This can occur as a result of the head and skull coming into contact with an object, or where an object comes into contact with the head and skull. Penetrating head injuries are associated with a high rate of epilepsy. Anoxic brain injury results from a deprivation of oxygen to the brain. Medical negligence is likewise a cause of brain injury – from the failure to diagnose or treat stroke to the failure to properly deliver a child. Sadly, brain injury can and does result from a wide array of events.
Approximately 80% of the brain is comprised in three general areas-the cerebral cortex (cerebrum), the cerebellum, and lastly the brain stem.