Traumatic Brain Injury

Traumatic Brain Injury

 Traumatic brain injury (TBI) also known as intracranial injury (ICI) is one of the greatest ugly phenomenon that   have befallen us worldwide. It has led to the death and disability around the globe and presents major worldwide socioeconomic and health problems. It is the number (1) cause of coma and plays a significant role in half of trauma deaths. It is the leading cause of brain damage in children and young adults to mention but a few. It is on this note, that we would like to bring to the notice of general public through this write up, what this ugly phenomenon (TBI) is all about, causes  and epidemiology (rate of spread), the diagnosis and prevention of it and  lastly the management cum treatment of the ugly phenomenon called traumatic brain injury.

Definition

Traumatic brain injury (TBI) also called intracranial injury occurs when an external force traumatically injures the brain. That is damage to the brain resulting from external mechanical force, such as rapid acceleration or deceleration impact, blast waves, or penetration by a projectile. When this occurs, the brain function is temporarily or permanently impaired resulting in structural damage that may or may not be detectable with current technology. However, traumatic brain injury is one of two subsets of acquired brain injury (brain damage that occur after birth); the other involve external mechanical force (is include stroke and infection) all traumatic brain injuries are head injury, but the latter term may also refer to injury to other part of the head. Therefore, the term head injury & brain injury are often used interchangeably.

Similarly, brain injuries also fall under the classification of central nervous system injuries and neuron trauma. Hence in neurophysiology research literature, in general, the term “traumatic brain injury” is used to refer to non-penetrating traumatic brain injuries.

 Epidemiology

 Traumatic brain injury is a leading cause of death and disability around the globe and it presents a major worldwide social, economics and heath problem. Findings on the frequency of each level of severity vary based on the definitions and methods used in studies. A world health organization study estimated that between 70 and 90% of head injuries that receive treatment are mild and a US study found that moderate and serve injuries each account for (10% of TBI with the rest mild. The incidence of TBI varies by Age, Gender, Region and other factors. Findings of incidence and prevalence in epidemiological studies vary base on such factors as which grades of severity are included. The annual incidence of mild TBI is difficult to determine but may be 100-600 people per 100,000. Furthermore, the inconsistency in the definition and classification of traumatic brain injury (TBI) along with the differences in data collection has made the epidemiology of TBI vary difficult to describe accurately in the sense that, patients with mild TBI may not present to the hospital, and the ones who do present may be discharged at the emergency department without adequate documentation. Also TBI severe TBI with associated death at the scene of the accident or during transport for the hospital also may not be counted for completely in data collection for TBI epidemiologic studies.

Mortality Rate

In the US, the mortality (death rate) rate is estimated to be 25% by 30 days after TBI. A study on Iraq war soldiers found that severe TBI carries a mortality of 30-50%. Deaths have declined due to injuries treatments and systems for managing trauma in society wealthy enough to provide modern emergency and neurosurgical services. The fraction of those who die after being hospitalized with TBI fell from almost half in the 1970s to about a quarter at the beginning of the 21st century. Paradoxically, this decline in mortality has led to a concomitant increase in the number of people living with disabilities that result from TBI.

Among children Aged 0-14 years, an estimated 475,000 TBIs occur each year. Rates are higher among children aged 0.4yrs. Death & hospitalization rates are highest among black children aged 0-9years compared with whites in TBI’s related to motor vehicle accidents (MVAs)

High-risk population

Some particular segments of the population are at increased risk of sustaining a TBI. This group includes:-

–         Young people

–         Men

–         Individual with a history of substance abuse

–         Low income individual

–         Individual who have suffered a previous TBI

Sex

Men are approximately twice as likely as women to sustain TBI. The ratio approaches parity as age increased likelihood of TBI caused by falls, for which males and females have similar risks in later life.

Age

The risk of TBI peaks when individuals are aged 15-30 years the risk is at its highest for individuals aged 15-24years and these group has the highest mortality rate. Twenty percent of TBI’s occur in the pediatric age group (17 years) the highest mortality rate (32.8 cases per 100,000 people) is found in person’s age 15-24years. The mortality age of the elderly patients are 65 years older is about 31.4 individual per 100,000 people.

Classification

Traumatic brain injury is one of two subjects of acquired brain injury (brain damage that occur after birth); the other subset is non-traumatic brain injury, which does not involve external mechanical force. TBI is usually classified base on

•       Severity

•       Anatomical features of the injury

•       Mechanism (the causative forces)

(A) Mechanism

Here TBI is classified in

–         Close

–         Penetrating head injury

•   A close, (also called non-penetrating, or blunt) injury occurs when the brain is exposed.

–         A penetrating or open, head injury occurs when an object pierces the skull and breaches the dura mater, the outermost membrane surrounding the brain.

 B, Severity

 Severity of traumatic brain injury

 

 

 

Mild

GCS (Glasgow Coma Scale) PTA (Post Traumatic Amnesia) LOC (loss of Consciousness)
13-15 < 1 day 0.30minites
Moderate 9-12 > 1 to < 7 days > 30minites to 24hours
Severe 3-8 > 7 days >24 hours

Brain injuries can be classified into mild, moderate and severe categories. The Glasgow coma scale (GCS), the most commonly used system for classifying TBI severity, grades a person’s level of consciousness on a scale of 3-15 based on verbal, motor and eye-opening reactions to stimuli. It is generally agreed that a TBI with a GCS of 13 or above is mild; 9-12 is moderate and 8 or below is severe. Similar system exists for young children. However, the GCS grading system has limited ability to predict outcomes. Because of this, other classification systems such as the one show in the table are also used to help determine severity. A current model developed by the Department of Defense and Department of veterans Affairs uses all three criteria of GCS after resuscitation duration of post traumatic amnesia (PTA), and loss of consciousness (LOC) it also has been proposed focal changes that are visible on neuro-imaging such as swelling, focal lesions, or diffuse injury as method of classification. Grading scale also exist to classify the severity of mild TBI commonly called also concussion, there use during of LOC, PTA and other concussion symptoms .

TBI may also be divided into primary injury and secondary injury. Primary injury is induced by mechanical force and occurs at the moment of injury while secondary injury is mechanical induced. It may be delayed from the moment of impact, and it may superimpose injury on a brain already affected by a mechanical injury.

Pathological Features

Systems also exist to classify TBI by its pathological features. Lesions can be extra-axial (occurring within the skull but outside the brain) or intra-axial (occurring within the brain tissue). Damage form TBI can be focal or diffuse, confined to specific areas or distributed in a more general manner, respectively. However it is common for both types of injury to exist in a given case. Diffuse injury manifest with little apparent damage in neuro-imaging studies, but lesions can be seen with microscopy techniques post-mortar and in the early 2005. Types of injury considered diffuse includes edema and diffuse axonal injury which is widespread damage to axon including white matter tracts and projection to the cortex. We also have focal injuries often produce symptoms related to the functions of the damaged area. Examples of focal injury include, cerebral (laceration which is common in or bit frontal cortex, cerebral contusion bruising of the brain tissue) intracranial hemorrhage (involves bleeding that is not mixed with tissue). Intracerebral hemorrhage. Involves bleeding of the brain tissue itself, is an infra-axial lesion. Extra-axial lesion includes Epidural hematoma (Bleeding into the area between the skull & dura matter. Subdura  hematoma (Bleeding   between the dura matter and arachnoid’s matter).

Subarachnoid hemorrhage (bleeding into the space between arachnoid and piamater) intraventricular hemorrhage occurs when there is bleeding in the ventricle.             

 Causes and Mechanism

 The most common causes of TBI includes violence, transportation accidents, construction, and sports motor bikes are major causes, increasing in significance in developing countries as other causes reduce. The estimates th between 1.6 and 3.8 million traumatic brain injuries each year are a result of sports and recreation activities in the US. In children aged two to four, falls are the most common cause of TBI, while in older children traffic accidents compete with falls for this position. It is the third most common injury to result from child abuse. Abuse causes 19% of cases of pediatric brain trauma, and the death rate is higher among these cases.

Domestic violence is another cause of TBI, as are work-related and industrial accidents. Firearms and blast injuries from explosions are other cause of TBI, which is the leading cause of death and disability in war zones.

Mechanisms

Physical forces

The type, direction, intensity, and duration of forces all contribute to the characteristics and severity TBI. Forces that may contribute to TBI include Angular, Rotational, Shear, and Translational forces. Even in the absence of an impact, significant acceleration or deceleration of the head can cause TBI, however in most cause a combination of impact and acceleration is probability to blame. Forces involving the head striking or being struck by something, termed contact or impact loading, are the cause of most focal injuries and movement of the brain within the skull, termed non contact or inertial loading, usually causes diffuse injuries. The violent shaking of infant that causes shaken baby syndrome commonly manifests as diffuse injuries. In impact loading, the force sends shock waves through the skull and brain, resulting tissue damage. Shockwaves cause by penetrating injuries can also destroy tissue along the path of a projectile, compounding the damage caused by the missile itself. Damage may occur directly under the site of impact, or may occur on the side opposite the impact (coup and centre coup injury respectively).

Primary and Secondary Injury

        A large percentage of the people killed by brain trauma do not right away but rather days to weeks after the event, rather than improving after being hospitalized, some 40% of TBI patients deteriorate. The deteriorations is caused by secondary injury, a complex set of cellular processes and biochemical cascades that occur in the minutes to days following the trauma. Primary brain injury is the damage that occurs at the moment of trauma when tissues and blood release are stretched, compressed, and thorax).

Secondary injury events include

  • Damage to the blood-brain barrier,
  • Release of factors that cause inflammation,
  • Free radical overload,
  • Excessive release of the neurotransmitter glutamate,
  • Influx of calcium and sodium ions into neurons, and
  • Dysfunction of mitochondrial.

Other factors include. Changes in the blood flow to the brain

  • Ischemia.
  • Insufficient  blood flow (cerebral hypoxia),
  • Insufficient oxygen in the brain cerebral oedema, and
  • Reduction of intracranial pressure due to swelling a mass effect from a lesion, such as a hemorrhage.

Signs and Symptoms

The symptoms are dependent on the type of TBI (diffuse or focal) and the brain that is affected. Unconsciousness tends to last longer for people with injuries on the left side of the brain than for those with injuries on the right. Symptoms are also dependent on with injuries severity. With mild TBI, the patient may remain conscious or may lose for conscious for a few seconds or minutes.

Other symptoms due mild TBI injury

–       Headache,

–       Vomiting,

–       Nausea,

–       Lack of motor coordination,

–       Dizziness/loss of balance,

–       Lightheadedness, fatigue or lethargy and

–       Changes in sleep patterns.

*       Symptoms due to moderate severe injury;

Cognitive deficits; including deficits in Attention, Distraction, Concentration, Memory, Speech of processing, confusion, perseveration impulsiveness, language processing.

*       Speech and language

–       Aphasia (expressive and receptive)

Slurred  speech.

*       Sensory

–       Difficulties with interpretation of Touch, Temperatures, Movement, Limbs movement and Position and Fine discrimination.

*       Vision

–       Partial or total loss of vision

–       Diplopia

–       Anisocoria (inequality of pupil size between both eyes)

–       Blurred vision, Nystagmus, Photophobia

*       Hearing

–       Tinnitus, Hearing loss, sensitivity to sounds

*       Smell

–       Anosmia (loss of smell)

*       Taste

–       Complete or partial aguesia

*       Seizures

–       Epileptic convulsions involving disruption in consciousness, sensory perception or motor movement

*       Physical changes

–       Paralysis

–       Chronic pain

–       Sleep disorders

–       Reduced control of bowel and bladder

–       Changes in appetite

–       Menstrual difficulties.

*Socio-Emotional

–       Dependent   behavior

–       Irritability

–       Aggression

–       Alexithymia

 Complications

The complications are actually distinct medical problems that may arise as a result of the TBI. The result of TBI vary widely in type and duration, they include:-

–       Physical

–       Cognitive

–       Emotional and behavioral complication.

It can cause a prolonged or permanent effect on consciousness which includes.

–       Coma: this is a state in which the patient is totally unconscious and cannot be aroused even with strong stimuli

–       Stupor: is a state of partial or near complete unconsciousness in which the patient is lethargic, immobile, and has a reduced response to stimuli.

–       Persistent vegetative state: is a condition in which awake patients are unconscious and unaware of their surroundings and the cerebral cortex is not functioning.

–       A minimally conscious state: This is a condition in which patients have a reduce level of arousal and may appear on the surface to be in a persistent vegetative state but are capable of demonstrating the ability to actively process information.

–       Locked in syndrome: This is a condition, in which a patient is aware and awake, but cannot move or communicate due to complete paralysis of the body.

–       Brain death: is the irreversible loss of measurable brain function, with loss of any integrated activity among distinct areas of the brain. Breathing and heart function must be maintained with assistive devices.

*       Cognitive deficits: Most patients with severe TBI who recover consciousness suffer from cognitive disabilities including the loss of many higher-level mental skills. Cognitive deficits that can follow TBI includes

–       Impaired attention;

–           Disrupted insight,

–          Judgment and through;

–         Reduced processing speed; and

–        Deficits in executive functions such as abstract reasoning, planning, problem solving, and multitasking.

*       Emotional and Behavioral problems.

TBI may cause an individual to develop emotional and behavioral problems which includes;

–       Obsessive compulsive Disorder, Schizophrenia

–       Irritability, personality change etc.

*       Physical complications:

–       Pain, especially Headache, is a common complication following a TBI

–       Deep venous thrombosis (as a result of being unconscious and lying down for a long period) this can also cause pulmonary embolism.

–       Pressure sores, Pneumonia or other infections and progressive multiple organ failure.

Other serious complications includes

–                     Parkinson’s disease, a chronic and progressive disorder, may develop years after TBI as a result of damage to the basal ganglia. Other movement disorders include Tremor, Ataxia (uncoordinated muscle movements) myoclonus (shock-like contractions of muscles),

–                     Skull fractures can tear the meninges, the membranes that cover the brain, leading to leaks of cerebrospinal fluid (CSF). A tear between the dura  and are arachnoids membrane called a CSF fistula, can cause CSF to leak out of the subarachnoid space into the subdura space called Subdural hygroma.

–     Pneumocephalus: occurs when air enters the intracranial cavity and becomes trapped in the subarachnoid space. Injection within the intracranial cavity  are a dangerous complication of TBI.

–         Hydrocephalus; post traumatic ventricular enlargement, occurs when CSF accumulates in the brain, resulting dilatation of the cerebral ventricles and increase in ICP (Intracranial pressure).

 Diagnosis, Prevention and Treatment

DIAGNOSIS

Diagnosis is suspected based on lesion circumstances and Clinical evidence, most prominently a neurological examination, For example; Checking whether the pupils constrict normally in response to light and  signing a Glasgow coma score. Neuroimaging helps in determining the diagnosis and prognosis and in deciding what treatments to give. The preferred Radiological test in the emergency setting is computed tomography (CTscan): it is quick, accurate and widely available. Follow-up CT scans may be performed later to determine whether the injury has progressed.

Magnetic resonance imaging (MRI) can show more detail than CT, and can add information about expected outcome in the long term. It is more useful than CT for detecting injury characteristics such as diffuse axonal injury in the longer term. However, MRI is not used in the emergency setting for reasons including its relative inefficacy in detecting bleeds and fractures, its lengthy acquisition of images, the inaccessibility of the patient in the machine, and its incompatibility with metal items used in emergency care. Other techniques may be used to confirm a particular diagnosis. X-rays are still used for head trauma but evidence suggests are not useful; head injuries are either so mild that they do not need imaging or severe enough to merit the more accurate CT.

–         Angiography: May be used to detect blood vessel pathology when risk factors such as penetrating head trauma are involved.

–         Functional imaging can measure cerebral blood flow or metabolism, inferring neuronal activity in specific regions and potentially helping to predict outcome.

–         Neuropsychological assessment can be performed to evaluate the long term cognitive sequels and to aid in the planning of the rehabilitation. Instruments range from short measures of general mental functioning to complete batteries formed of different domain specific tests.

–         Glasgow coma scale: (GCS) is neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment. A patient is assessed against score between 3 (indicating deep unconsciousness) and either 14 (original scale) or 15 (the more widely used modified or revised scale).

 PREVENTION

The following practices could help reduce the incidence of TBI:

  1. Use of seatbelts in motor vehicles, in addition to securing children on the back seats.
  2. Avoiding alcohol in situations where still and coordination in such conditions.
  3. Firearms should be stored with the safety on
  4. Preventing falls by installing handlebars/handrails in bathrooms, using non slip marts in slippery places, installing handrails on staircases, installing protecting bars (window guards) on balconies and windows.

Treatment

The treatment of TBI is usually divided based on the acute and chronic stages of the condition.

Acute State

The acute stage can be referred to as the period just after the injury and treatment here entails maintenance of a steadily low intracranial pressure (ICP), maintenance of a patient airway and adequate perfusion; seizure prevention maintenance of body temperature and surgical procedures to remove, if any, the penetrating objects and also to debride any severely affected tissue.

Maintenance of low ICP

This can be achieved by the following:

–         Insertion of a catheter into the skull to allow drainage of CSF

–         Tilting the patient to allow flow into the neck veins

–         Using hypertonic saline (though with caution, to prevent electrolyte imbalances).

–         The use of Diuretics and other agents. Mannitol (An osmotic agent has been extensively studied for this purpose).

Maintenance of a patient  airway and adequate perfusion to the brain.

To maintain a patient airway, endotracheal intubations and mechanical ventilation are applied, and then to keep the blood supply to the brain potent, intravenous fluids may be given to prevent hypotension, although the blood pressure can be kept at artificial high using norepinephrine or similar vasoconstrictor substances.

Maintenance of a normal body temperature; This is necessary too, in order to keep the brains metabolic activities at a normal state, as increased temperature can cause a brain metabolic rate risk. Efficiently depriving it of necessary nutrients.

Seizures are common and are usually treated using benzodiazepines (a class of general anesthetics which includes thiopental, etc) but these drugs should be used with caution because they may lower blood pressure and depress breathing.

Surgical procedures on mass lesions (such as haematomas and confusions which cause a significant mass effect ie shift of intracranial structures) and to eliminate the object that have penetrated the brain may also be performed, control of bleeding too, from damaged blood vessels, and craniotomy, which involves removal of a part of the skull and this may be needed to remove fractured parts of the skull. Decompressive craniectomy, (another surgical procedure) in which part of the skull is temporarily removed, is used to treat haematomas.

Chronic Stage

The chronic stage of treatment typically involves helping the individual to attain a certain level of normalcy after a traumatic brain injury, a multidisciplinary approach is often employed which involves physiotherapy to help with movement, speech and language therapy to assist with speech and language as the name implies, psychotherapy which involved the remedy of psychological problems as pertaining to brain function. Medication may also be used for aggressive behavior Amantadine, methylphenidate, bromocriptine and also for attention and concentration-carbamamapazine and amitriptyline.

In bedridden patients, Deep vein thrombosis and heterotypic ossification are common problems and there should be detected and treated to by the use of appropriate methods-Anticoagulants like warfarin for the former, and ROM (Range of movement) exercise and NSAIDs (Non-steroidal Anti-inflammatory Drugs) can be used in the prevention and management.

 Recommendation and Conclusion

Recommendation

The following recommendations are necessary in order to effectively reduce the incidence of traumatic brain injuries in our society. For these recommendations to be effectively carried out, the government and the masses should establish a working relationship that enables the masses abide by a set of rules and regulations that would effectively reduce TBI incidence. The recommended rules/regulations should include, though should not be limited to:

  • Compulsory use of helmets by cyclists.
  • Enforcement of speed limits which all individual should abide by for their own safety.
  • The use of seatbelts within all four-wheeled vehicles, which is already being enforced, should continue to be practiced and enforce by Federal Road Safety Corps.(FRSC).
  • Storey buildings should compulsorily have protected balconies to prevent accidental falls.
  • Mothers should keep an eye on their children at all times, to reduce the infantile incidence of TBI.
  • Guns, if they must be possessed, should have their safety or at all times, and when in use, should be pointed away from every non-assailant at that moment.

Conclusion

In conclusion, TBI is an emergency situation and can occur any time, any day, any moment, therefore medical practitioners should be sensitized on how to manage this condition. having thoroughly discussed what TBI is all about, its causes, prevention and treatment, is now led for us to embrace and put into practice the useful preventive majors in order to reduce or probably eradicate this ugly phenomenon called TBI

 

 

One Comment on “Traumatic Brain Injury”

  1. Akparah Eunice says:

    please i need more articles on this topic traumatic brain damage.
    Thank you

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