The brain is one of the most important organs in the human body. It allows us to think, to reason, to learn, and it brings our universe to life. It is how we experience our environment, language, and relationship to others.
All of this from a three-pound organ with a striking resemblance to a Nerf Football.
But the brain is all this and so much more. Our brain contains 100 billion nerve cells (neurons) that not only string our thoughts together and allow us to coordinate our physical actions, but also regulate unconscious body processes like breathing.
The brain's neurons (also known as the "grey matter") transmit and gather signals that are communicated through millions of nerve fibers called dendrites and axons (the "white matter" of the brain)
What Are Brain Injuries?
Just as each brain is unique, each brain injury is unique. The brain may receive several different types of injuries depending upon the type and amount of force that impacts the head. The type of brain injury may affect one area of the brain, various areas of the brain, or all areas.
Brain injuries may be minor and invisible, or traumatic and severe. Depending on the type of brain injury, it may take a lifetime to recover.
It is estimated that approximately five million people in the United States sustain head injuries a year. More than a third result in permanent damage.
Brain damage is potentially very serious, if not deadly. Impairment can occur that can drastically interfere with a person's everyday ability to regulate mood, temperament, decision-making, and skills. These consequences may be life-long.
What Causes Brain Injuries?
Brain injury may be caused by a variety of situations, including (but not limited to):
- Electric Shock
- Head injuries
- Traumatic Brain Injury
Impairments, deficits, and skill-loss vary greatly from injury to injury, depending on which part of the brain is damaged and how severely it is damaged. Some of the most common deficits include:
- Difficulty with memory
- Difficulty with mood
Other, more complex damage may make it difficult to function in more stressful or difficult situations. Organizational, reasoning, and cognitive functioning are examples of this type of damage.
Some types of damage occur with no signs or symptoms, such as whiplash or shaken baby syndrome.
Treatment success and progress may differ greatly from case to case and from time to time. It is not uncommon to make progress, then hit a plateau or a set-back. Be patient - this is not evidence that progress has ceased.
Traumatic Versus Acquired Brain Injury:
There are two classes of brain injury: traumatic brain injury and acquired brain injury.
Traumatic Brain Injury (also known TBI or intracranial injury) occurs when an external force traumatically injures the brain. TBIs are classified based upon severity, mechanism, or other features. TBI is the major cause of death and disability worldwide.
Acquired Brain Injury (ABI) is brain damage caused by events post-birth, rather than as a part of a congenital or genetic disorder. These result from damage to the brain caused by tumors, strokes, anoxia, hypoxia, degenerative diseases, toxins, near-drownings, and other conditions not necessarily caused by traumatic force.
Types Of Traumatic Brain Injury:
Concussion - occurs when the brain receives trauma from an impact or a sudden movement or momentum changes. The blood vessels may stretch or cranial nerves can be damaged. It can cause diffuse anoxal injury resulting in temporary or permanent damage. It can take a few months to years to heal from a concussion.
Causes: A concussion may be caused by direct blows to the head, gunshot wounds, violent shaking, or whiplash. A person may briefly lose consciousness or remain conscious through a concussion.
Symptoms: symptoms may be subtle and not immediately apparent and may last days, weeks or longer. Most common include headache, amnesia and confusion.
Diagnosis: Concussions may or may not show up on brain imaging scans as skull fracture, brain bleeds, or swelling may or may not be present.
Cerebral Contusion - a bruise of the brain tissue associated with multiple microhemorrhages, small blood vessel leaks into the brain tissue. They are frequently associated with edema, which may increase intracranial pressure. Cerebral contusions occur in 20-30% of severe head injuries.
Causes: A contusion is often the result of a direct blow to the head.
Symptoms: vary upon the severity and range from minor headaches, confusion, dizziness, loss of consciousness, nausea and vomiting, difficulty with coordination, and movement. Cerebral contusions may also impact memory, speech, vision, or hearing depending upon the location of the injury.
Diagnosis: Generally made through brain imaging scans like MRI or CT Scan.
Treatment: Large contusions may require surgery to remove them.
Coup or Contrecoup - focal (occurring in localized, rather than diffuse, spots of the brain) cerebral contusions on both the site of impact and on the complete opposite side of the brain. It's likely that these injuries occur thanks to inertia - the brain continues moving after the skull is stopped by a fixed object.
Diffuse Axonal (DAI) - is one of the most common and devastating types of traumatic brain injury that causes widespread damage. Injury occurs because the unmoving brain lags behind the movement of the skull, causing a tear in the brain's structures. This causes excessive tearing of nerve tissue throughout the brain, which may cause chemicals to be released, causing additional brain injury. The tearing of the nerve tissue disrupts the brain's regular communication and chemical processes. DAI is classified by severity of injury:
- Grade I - widespread axonal damage is present without focal abnormalities seen.
- Grade II - Grade I damage plus focal abnormalities, especially in the corpus callosum.
- Grade III - Grade I and Grade II damage plus rostral brain stem injury and often tears in tissues.
Causes: shaking or strong rotation of the head, such as shaken baby syndrome, or rotational forces such as a car accident.
Symptoms: the disturbance within the brain may produce temporary or permanent widespread damage, coma, or death. Diffuse Axonal Brain Injury may cause a variety of functional impairments depending upon where the tears within the brain are located.
Prognosis: over 90% of people who suffer DAI lapse into coma and never regain consciousness. Those who do wake often remain significantly impaired.
Diagnosis: DAI is usually undetectable via CT Scans. MRI examinations may be more helpful.
Treatment: standard treatment for head injury, including stabilizing patient and limiting increase in intracranial pressure.
Penetrating Brain Injury (also called Open Head Injury) - is a head injury in which the dura mater, the outer layer of the meninges, is breached. Penetrating Brain Injuries are mostly focal and affect a specific area of the brain.
Causes: Penetrating Brain Injury can be caused by high-velocity projectiles or objects traveling lower velocities, or bone fragments from a skull fracture driven into the brain.
Symptoms: Penetrating Brain Injuries are more likely to cause infections, but the symptoms of Penetrating Brain Injury are similar to a closed head injury. Intracranial pressure increases due to swelling, blood vessels can be damaged, causing intracranial hematomas, which lead to a biochemical cascade called the ischemic cascade.
Diagnosis: Penetrating Brain Injury may be evaluated via CT Scan, MRI, or X-ray. (note: MRI's are only used if the penetrating brain injury does not involve metal or metal fragments)
Treatment: surgery may debride or repair the injury or relieve elevated intracranial pressure.
Types of Acquired Brain Injury:
Cerebral Hypoxia - a hypoxic brain injury occurs when the brain receives some, but not enough, oxygen. The brain requires a constant supply of oxygen to function properly.
Causes: smoke inhalation, carbon monoxide poisoning, choking, ALS, high altitudes, tracheal pressure, strangulation, cardiac arrest, cardiac arrhythmia, complications of general anesthesia, drowning, drug overdose, stroke, very low blood pressure.
Symptoms: symptoms of cerebral hypoxia range from mild (inattentiveness, poor judgement, uncoordinated movement) to severe (no breathing, coma)
Diagnosis: Arterial blood gases, CT Scan, Echocardiogram, ECG, EEG, and head MRI.
Treatment: an emergency condition that requires immediate treatment. Basic life support is most important and may include assisted ventilation, controlling heart rhythm/rate, fluids to raise blood pressure, medications to calm seizures. Prognosis: depends upon the extent of the brain injury, how long the brain went without oxygen, and whether the brain was also deprived nutrients.
Anoxic Brain Injury - ABI occurs when the brain does not receive any oxygen - brain cells require oxygen to survive. Brain cells begin to die approximately four minutes without oxygen.
Causes: clot prevents blood flow, blood pressure is too low during shock, or sudden heart failure. Blood that reaches the brain doesn't carry enough oxygen (like during lung disease), or exposure to toxins that prevent oxygen in the blood being used by cells in the brain.
Symptoms: Recovery from anoxic brain damage can be uncertain and take a long time. Recovery is based upon how long the brain cells were left without oxygen. Severe damage can lead to a coma or persistent vegetative state. Mild-to-moderate anoxic brain injury may cause headaches, confusion, decreased attention span, mood swings/personality change, intermittent loss of consciousness, seizures, abnormal muscle jerks.
General Symptoms of Brain Injuries:
It is not uncommon for those with brain injuries to experience mood changes, memory loss, and fatigue. Other symptoms include:
- Memory problems
- Concentration issues
- Attention issues
- Misplacing items
- Difficulty with cognition
- Communication difficulty
- Stuttering or stammering
- Difficulty completing tasks
Psychological effects include:
- Fear of loss of control
- Startling easily
- Terror or panic
- Feelings of dread
- Social isolation
- Laughing and crying without cause
- Mood swings
- Urges to injure someone
- Shouting or throwing things
- Uncontrolled temper
- Heart racing
- Headache or pain
- Increased blood pressure
- Ringing ears
- Sensitivity to touch
- Loss of strength
- Feeling tense
- Changes in appetite
- Changes in sleep
Treatment for Brian Injuries:
Treatment is typically two-fold. On one hand, it is important to restore function. On the other, it works around a permanent injury. Damage is often the most severe immediately following the injury. Damage may be specific to an area, moderate, or severe. Swelling can cause pressure on the brain that may cause additional problems. Conducting tasks that tax the brain can help with mental flexibility. Rehab is often conducted much as it would be for a physical injury or impairment. Mood- and temperament-related symptoms, such as depression and anxiety, may be treated with medication. Continual research and study is being conducted on brain injuries and function to help improve understanding and treatment options.
Levels of Brain Injury:
Mild Traumatic Brain Injury (Glascow Coma Score 13-15)
- Loss of consciousness lasts a few seconds or minutes
- Loss of consciousness may not occur - instead person may be dazed or confused
- Brain scans may appear normal
- Diagnosed only when there a change in mental status at time of injury, which signifies that brain functioning has been altered
Moderate Traumatic Brain Injury (Glascow Coma Scale 9-12):
Most brain injuries result from moderate/minor head injuries such as a non-penetrating blow to the head or a violent shaking of the head. Disabilities may be non-existent or life-long. Occurs:
- Loss of consciousness from a few minutes to few hours
- Confusion lasts days to weeks
- Physical, cognitive and/or behavioral impairments last for months or forever
Severe Brain Injury (Glasow Coma Scale 1-8)
Severe brain injury typically result from crushing blows or penetrating head wounds. These injuries, crush, rip and sheer delicate brain tissue. These are the most life-threatening and non-reversible head injuries. Heroic measures must be performed to treat such injuries. Typically rehabilitation is incomplete and there is no return to pre-injury status.
What is Brain Death?
The brain can survive approximately six minutes after the heart stops (one of the reasons to learn CPR is that if CPR is begun within six minutes following cardiac arrest, the brain may survive. After six minutes without CPR, the brain begins to die.). Resuscitation allows the doctor time to assess and treat the damaged brain. Medication and mechanical ventilation allow for tissue oxygenation, but severe brain damage or a prolonged period without oxygen or glucose causes death of the brain.
Brain death is when the entire brain - including brain stem - has irreversibly lost all function. Legal time of death is when a physician determines that the brain and the brain stem have irreversibility lost all neurological function.
Brain Death Versus Coma?
People who suffer brain death are not in a coma, and people in a coma may or may not progress to brain death. People in comas will still exhibit some variable neurological signs. Any electrical impulse leaving the brain in reaction to an external stimulus is a sign that a person is in a coma. People who suffer brain death will not exhibit these signs.
Deep Coma Versus Persistent Vegetative State?
People in a coma may be in a deep coma or a vegetative state. A person in a coma usually requires hospital care, while a person in a vegetative state may be released to at-home family care. A person in a vegetative state has much lower-brain function and a bit more upper brain-stem function than one in a deep coma. People in vegetative states or deep comas are legally considered alive.
Additional Brain Injury Resources:
Brain Injury Association of America - national organization dedicated to increasing access to quality health care and raising awareness and understanding of brain injury through advocacy, education, and research. it has a nationwide network of over 40 state affiliates and hundreds of local chapters and support groups, providing help for individuals with brain injury, their families, and medical professionals.
Brain Trauma Foundation - dedicated to improving the outcome of Traumatic Brain Injury (TBI) patients worldwide by developing best practices guidelines, conducting clinical research, and educating medical professionals and consumers.
Krempels Center - New Life After Brain Injury - a nonprofit organization dedicated to improving the lives of people living with brain injury from trauma, tumor, or stroke.
BrainCenter.Org - a website that provides additional information regarding how the brain works, the causes of brain injuries, and tips for how to help a family member recover from a brain injury.