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Diffuse axonal injury or DAI is potentially a sever formal traumatic cerebrum trauma or lesion which effects from quick transformations in velocities of skull and brain is quickly shifted inside the skull when the injury is occurred. The brain motion underlying the Diffuse Axonal Injury is rotational also rotate angular.
Explanation
The brain composed of gray matter and white matter and these two tissues types have different densities. Gray matter presents on the surface of noetic or olfactory lobe and hind brain. Brain cells or White matter forms bulk of extensive parts of neotic or olfactory lobe (Hemisphere) and hind brain , the Cerebellum. Diffuse axonal injury is occurred by the result of combinations of the rate of change in velocities , slow down , and sudden movement of the skull and compressive forces. Where in the injury due to the loss of blood, this trauma affects individual nerve fibers.
The neuron body and an axon is present in the nerve fibers which are disturbed by the lesion. Neuron body and an axons produce signals which are transferred to the nerve and nerves perform their function. Nerve cells become dead with the interruption of the acceleration and deceleration gravity forces because these produce the inflammation in to brain region which is effected by the injury. Due to the inflammation various limits or problems occurs such as it limits the shower the blood to – wards the brain and the breach of the brain.
Mechanism of diffuse axonal injury
DAI is caused by prevailing sharing force occurred into the head are rapidly increasing or decreasing in the amount which take place by road vehicles accidents. Diffuse Axonal Injury or (DAI) which is also caused by the child violent attack (shaken baby syndrome), during a fall , during sports incident attack but vehicle accident is the major cause of diffuse axonal injury.
The major cause of DAI is disrupting the axon. Axons have white and gray mater, trauma which is found in gray and white matter by using CT and MRI exams of post-mortem of brains. DAI also includes interrupted axonal transport swelling and as well as microtubules axonal broking. In DAI , due to acceleration and deceleration the brain moves in backward and forward position rapidly inside the skull.
Symptoms of diffuse axonal injury
The traumatic Diffuse Axonal Injury commonly cause unconsciousness which is sever cause of DAI which may be remain about sixth or more than six hours . When Diffuse Axonal Injury is not sever the patient remain in conscious state but may cause other type of brain damage but mainly depends upon the which area of brain is damaged or effected . Other symptoms of Diffuse Axonal Injury instead of unconsciousness are confusion and disorientation , vomiting , nausea , headache , trouble of sleeping , longer sleeping routine than normal sleeping , fatigue and patient cannot maintain his balance and this situation is called dizziness . Severe brain damage in diffuse axonal injury may result the patients to undergo in coma which may lasts for persons lifetime.
History of diffuse axonal injury
The history of diffuse axonal injury starts from the year of 1956 by the Strich Sabina. The reason is that Sabina was experienced or undergo these pineal cord trauma from several year.
Until 1956 this trauma of mantle was known as scattered determination of cerebellum and later on it as given the name of DAI in 1981 which was more precise . Sabina strict identified after several year and attempt the brain lesion was usually due to the diffuse injury of axons. The initial symptoms of DAI after the soft injury of brain and head is the pain in head and vomiting , wooziness, motion sickness, tiredness and weariness. But due to the saver or dangerous injury of the head trauma patients usually lose his thinking ability and undergo in the senseless level and may not be never from this situation.
Because of lack of proper treatment and care of diffuse axonal injury it leads several complications in brain and patients families also affected from this routine and patients sickness because it requires extreme care and protection. A famous actor suffered from diffuse axonal injury after vehicle accident in 2001 and he had severe trauma in head and he finally died in 2008. If the injury is mild or not sever the patient recover from the proper the treatment but he should has to be avoid from the secondary injury in the head.
Characteristics
In diffuse axonal injury (DAI) , the injury or trauma usually occurred in the white matter of the brain, and these injuries are of different size usually about 1 – 1.5 mm in diameter and are scattered in a characteristics ways. The portions of white matter which are may be affected by diffuse axonal injury are ‘brain stem’ ‘corpus callosum’ and ‘ cerebral Hemisphere ’. The other parts which are easily to b affected by diffuse axonal injury are brain lobes, cerebral cortex, basal ganglia, thalamus, and deep hemispheric nuclei. These areas are at high risk of lesions because of difference in velocities of these parts and other parts of the brain .
Histological characteristics
The axons are separated due to diffuse axonal injury, the main reason of axon separation is due to the pull of mechanic force during lesion which causes the separation of axons and this may takes hours to weeks after the first injury of DAI. The mechanism of secondary DAI injury is not properly known but it is thought that in the axolemma sodium channels are opened which allows the voltage gated calcium to be open and resultantly Ca2+ rush inside the cell. This cause the phospholipids and proteolytic enzyme to be activated which damages the cytoskeleton and mitochondria of the cell due to which axons are separated.
Cytoskeleton disruption
Typically the axons are flexible buy when we unbend the axons they become hard and resultantly the cytoskeleton would be damaged. The axons are continuously transported at the damaged area of cytoskeleton but this area become swell because the transport material is gathered at this point. When swelling spread and becomes large the axons are separated this point of cytoskeleton and these axons are travel backward to cell body where axons forms a bulk.
Calcium Influx
When cytoskeleton is interrupted by DAI the axolemma is also affected at the same time due to which Ca2+ enter into the cell and causing the release of various biological degrading processes. Soon after the diffuse axonal injury the Na+ and Ca+ level are increased and k+ is decreased in the axons cell.
Due to excess of Ca2+ in axons cells the mitochondria is damaged and resultantly phospholipases and proteolytic enzymes don not function properly due to which sodium channels are disturbed , the axoplasm and cytoskeleton are affected. Due excess of Ca2+ in the axons cell the brain cell swell and brain blood route is also affected. When calcium ions enter into the cell the calpain protein operate its function into the cell and ‘calpain medited spectrin proteolysis’ (CMSP) process starts its function after 15minutes or half an hour of brain injury. The spectrin molecules which are present on the surface of cytoskeleton hold the cytoskeleton membrane are destroyed by the calpain protein which kills the cells of cytoskeleton.
The calpain protein is also damage the microtubules subunit, nerurofilament and microtubules associated protein. ‘Cell apoptosis’ or ‘cell death’ also occurred due to calcium influx. Mitochondria , dendrites and cytoskeleton which are damaged by diffuse axonal injury have less ability to recover after the injury which lasts for about two or more weeks which cause the astrocytes to shrink.
Etiology
The most sever diffuse axonal injury occurred after heavy vehicles accidents which is the most common type Etiology injury. The process of escalate (speed up) and desecrate (slow down) in the brain due the compression forces in the white portion or matter of the brain and this lesions of axons is to minute to be seen by microscopic in the white and gray matter of the brain but usually DAI or diffuse axonal injury has majorly affected by the white matter. The diffuse axonal injury has no connection with the cytoskeleton injury.
Pathology
Besides of many side effects of the after the injury of the head the white matter of the brain is normally or usually affected by the truama of the diffuse axonal injury . Axoms are present in huge amount which are several meter in length the brain’s white and gray substances which present in brain and spinal cord are connected to each other by these axons.
The nerve impuses are transferred from the cell body of the axon toward the cerebrum and other parts of the body and these signals are regulated by the gray substance of the brain and skull. Trauma which is caused by the diffuse axonal injury can be of different size and the size usually be from one to eighteen mille meter in length.
This type of injury usually effect the prefrontal cortex and the cerebral cortex also called temporal and the frontal lobe. Instead of these parts other several type of the brain cell also affected by the lesion of DAI.
Epidemiology
The exact extent or occurrence of diffuse axonal injury is not known with accuracy but it is thought that the 10% of the traumatic brain injury (TBI) are due to the diffuse axonal injury in the hospitals patients . The sever diffuse axonal injury patient has less chances of recovery 25% patients of diffuse axonal injury are died due to DAI. The researchers have showed the diffuse axonal injury has a major extent on the shocking brain injury of TBI.
Path physiology
In the path physiology the granulocytes or neuron cells usually disassociate from other neurons and resultantly many parts of the brain cannot function normally and are affected by this injury. In diffuse axonal injury to study pathohysilogy three types of division are observer. In first category when trauma is mild or soft them in the white matter the only observed under microscope in the forebrain, brain cells.
But in second case when injury is of medium or average the truama is found in the brain cells and corpus collasum. In the third case after sever injury in the brain leads sever complication occurred in the brain and theses leads the patients under unconscious or senseless situation. The path physiology is usually the non structural cerebral lesion in which blood contributions to the brain is usually reduced due to which the brain ultimatum to dextrose or sugar is required is enlarged.
Histopathology
In histopathology the nerves cells are automatic disarrangement of cytosol after injury in which inflammation, proteolysis, in which particles or fragments of nerve cells are altered in which head moves rapidly in forward mad backward position.
Evaluation
In DAI the victim of head injured needs a special care because it is dangerous type of traumatic brain injury , TBI . The ultimate or final identification can be understood by the study of brain tissues in the post-mortem report.
For clinical study of diffuse axonal injury the clinical tools are used for examination of the clinical level diffuse axonal injury. By knowing the exact examination of head Injury we will estimate that it would be a head injury only or diffuse axonal injury. The injury of head in which the patient head is move rapidly forward or backward (the cytoskeleton disruption) also called acceleration and deceleration near head injury ii is estimated that the patients has DAI.
In Diffuse axonal injury the lesion also examined with the help of CT (computed tomography) but this method has less contribution in detecting the diffuse axonal injury . Recently the MRI (magnetic resonance imaging) , DTI (specific diffuse tensor imaging) are used for the identification of diffuse axonal injury.
Diagnose of diffuse axonal injury
To examine lesion after the diffuse injury of axons is a very tough tasks however now a day’s several medical and histological techniques are used in practice for the identification o the trauma, these approaches depends on the conditions and the size of the lesion. In the diffuse axonal injury victims for the identification of DAI the peculiar logical evidence is very difficult that is why the surgeons prefer the tactile and the ultra violet rays for identification of lesion or trauma.
At medical level for the identification of the trauma which is caused by the DAI the Mesmeric stentorian image or MRI technique has to with the CT SCANE. In human body the axons cells are found in the huge quantity that is why the many axonal cells are damaged soon after the lesion of diffuse axonal injury therefore sever conditions occur due to the lesion in the brain. For the detection of way of the neurons pathway in which fluid gathered after the trauma diffusion tensor imaging skill is applied . By this method surgeons also detect whether the white matter of brain is also affected or not if the injury is no sever.
With the help of ECG technique exports can be able to find the level of injury in a patient or doctors get enough information about the diffuse axonal injury and with ECG the export can found the victim condition of un – conscious level. Several others techniques are still used today for the examination of the diffuse axonal injury in the brain but to test whether the other parts or brain also affected with the DAI the ENT is used .
Radiographic techniques are also used for the detection of brain trauma. The diagnose of trauma is possible only after some days of the diffuse axonal injury and the surgeon can detect them under the ct scans because of the enough inflammation on the brain injury , contraction and other forces and if the injury related to the traumatic brain injury the surgeons can detect nineteen percent identification with this technique.
Treatment of diffuse axonal injury
The particular or specified therapy or surgery for the diffuse axonal injure is not found anywhere around the world because of the head lesion the patient goes to the coma or unconsciousness state the recovery is difficult and it is life time for patient . The diffuse axonal injury treatments or therapy is done like other lesion therapy of other parts of the brain or head which depends on the situations weather the head is saver or mild injury.
The one option for the treatment of DAI is to ménage the leve of inflammation on the brain , bleeding, and by the managing of nerve impulses tract which are generated by the axons specific steroids or drugs are used to control the inflammation on the brain . The treatment depends the patient condition and retrieval from diffuse injury relay on the individual; however other methods such as recreational therapy , physical , speech, occupational and counselling techniques are used.
Prognosis
The diffuse axonal injury patients has very less chances for recovery because of the brain lesion and deaths occur after such injuries. However if patients persist after such injuries they go into the coma and this condition is life time of the victim and they cannot retain the conscious state. In some cases the patient recover from the coma or unconscious state they suffer from other various difficulties of the brain issues .
The diffuse axonal patients recover completely if the lesion on the brain is lenient or mild the patient recover from the unconscious state. Patient should be avoided from viewing TV, reading books and perfuming exercises and from gaming and weight lifting, prevention measures should be announced or introduced about vehicle accidents like cars, and motorbikes, hevybikes, and helmits are used for protection from head injury.
Patient’s family cooperation and understanding about the injury is play an important role for treatment and therapy. In the time to come the therapy and the identification of diffuse injury in axons controlled with the help of our comparative knowledge about trauma and its therapy and path physiology of brain lesion. The best solution from avoiding diffuse axonal injury is the prevention and care from the sources which cause the injury.
