A Healthy Brain Before we can understand what happens when a brain is injured, we must realize what a healthy brain is made of and what it does. The brain is enclosed inside the skull. The skull acts as a protective covering for the soft brain. The brain is made of neurons (nerve cells). The neurons form tracts that route throughout the brain. These nerve tracts carry messages to various parts of the brain. The brain uses these messages to perform functions. The functions include our thought processes, physical movements, personality changes, behavioral changes, and sensing and interpreting our environment. Each part of the brain serves a specific function and links with other parts of the brain to form more complex functions. An Injured Brain When a brain injury occurs, the functions of the neurons, nerve tracts, or sections of the brain can be effected. If the neurons and nerve tracts are effected, they can be unable or have difficulty carrying the messages that tell the brain what to do. This can result in Thinking Changes, Physical Changes, and Personality and Behavioral Changes. These changes can be temporary or permanent. They may cause impairment or a complete inability to perform a function. Some possible changes are described below. Thinking Changes Memory Communication Perception Decision making Reading and writing skills Thought flexibility Planning Thought processing speed Safety awareness Sequencing Problem solving skills New learning Judgement Attention Organization Self-perception Physical Changes Muscle movement Taste Balance Muscle coordination Smell Speech Sleep Touch seizures Hearing Fatigue Sexual Functioning Vision Weakness
Personality and Behavioral Changes Social skills Self-monitoring remarks or actions Frustration Stress Emotional control and mood swings Reduced self-esteem Denial Appropriateness of behavior Irritability or agitation Motivation Self-centeredness Coping skills Depression Anxiety Anger management Excessive laughing or crying Functions of the Brain The brain is divided into main functional sections, called lobes. These sections or brain lobes are called the Frontal Lobe, Temporal Lobe, Parietal Lobe, Occipital Lobe, The Cerebellum, and the Brain Stem. Each has a specific function, as described below. Frontal Lobe Functions Attention and concentration Self-monitoring Organization Speaking (expressive language) Motor Planning Initiation Awareness of abilities and limitations Personality Mental flexibility Inhibition of behavior Emotions Problem Solving Planning and anticipation Judgement Temporal Lobe Functions Memory Understanding language (receptive language) Sequencing Hearing Organization Parietal Lobe Functions Sense of touch Spatial perception
Differentiation (identification) of size, shapes, and colors Visual perception Occipital Lobe Functions Vision Cerebellum Lobe Functions Balance Coordination Skilled motor activity Visual perception Brain Stem Functions Breathing Arousal and consciousness Attention and concentration Heart rate Sleep and wake cycles Right or Left Brain The functional sections or lobes of the brain are also divided into right and left sides. The right side and the left side of the brain are responsible for different functions. General patterns of dysfunction can occur if an injury is on the right or left side of the brain. Injuries of the Right Side of Brain can cause: Visual-spatial impairment Visual memory deficits Left neglect (inattention to the left side of the body) Decreased awareness of deficits Altered creativity and music perception Loss of the big picture type of thinking Decreased control over left-sided body movements
Injuries of the Left Side of Brain can cause: Difficulties in understanding language (receptive language) Difficulties in speaking or verbal output (expressive language) Catastrophic reactions (depression, anxiety) Verbal memory deficits Impaired logic Sequencing difficulties Decreased control over right-sided body movements Diffuse Brain Injury (The injuries are scattered throughout both sides of the brain) Reduced thinking speed Confusion Reduced attention and concentration Fatigue Impaired cognitive (thinking) skills in all areas Levels of Brain Injury Emergency personnel typically determine the severity of neurological injury to the brain by using an assessment called the Glascow Coma Scale (GCS) to. The terms Mild Brain Injury, Moderate Brain Injury, and Severe Brain Injury are used to describe the level of initial injury in relation to the neurological severity caused to the brain. There may be no correlation between the initial Glascow Coma Scale score and the initial level of brain injury and a person s short or long term recovery, or functional abilities. Keep in mind that there is nothing Mild about a brain injury again, the term Mild Brain injury is used to describe a level of neurological injury. Any injury to the brain is a real and serious medical condition. Mild Moderate Severe
Mild Traumatic Brain Injury Mild Traumatic Brain Injury (Glascow Coma Scale score 13-15) Mild traumatic brain injury occurs when: o Loss of consciousness is very brief, usually a few seconds or minutes o Loss of consciousness does not have to occur the person may be dazed or confused o Testing or scans of the brain may appear normal o A mild traumatic brain injury is diagnosed only when there is a change in the mental status at the time of injury the person is dazed, confused, or loses consciousness. The change in mental status indicates that the person s brain functioning has been altered, this is called a concussion. Symptoms of mild traumatic brain injury: o Headache o Fatigue o Sleep disturbance o Irritability o Sensitivity to noise or light o Balance problems o Decreased concentration and attention span o Decreased speed of thinking o Memory problems o Nausea o Depression and anxiety o Emotional mood swings This information is not intended to be a substitute for medical advice or examination. A person with a suspected brain injury should contact a physician immediately, go to the emergency room, or call 911 in the case of an emergency. Symptoms of Mild Traumatic Brain Injury can be temporary. The majority of people with Mild Traumatic Brain Injury recover after one year. Moderate Traumatic Brain Injury (Glascow Coma Scale core 9-12) A moderate traumatic brain injury occurs when: o A loss of consciousness lasts from a few minutes to a few hours o Confusion lasts from days to weeks o Physical, cognitive, and/or behavioral impairments last for months or are permanent. Persons with moderate traumatic brain injury generally can make a good recovery with treatment or successfully learn to compensate for their deficits.
Severe Brain Injury (Glascow Coma Score 8 or less) Severe brain injury occurs when a prolonged unconscious state or coma lasts days, weeks, or months. Severe brain injury is further categorized into subgroups with separate features: Coma Vegetative State Persistent Vegetative State Minimally Responsive State Akinetic Mutism Locked-in Syndrome Coma Coma is defined as a state of unconsciousness from which the individual cannot be awakened, in which the individual responds minimally or not at all to stimuli, and initiates no voluntary activities. Persons in a coma appear to be asleep, but cannot be awakened There is no meaningful response to stimulation. Persons who sustain a severe brain injury can make significant improvements, but are often left with permanent physical, cognitive, or behavioral impairments. Vegetative State (VS) Vegetative State (VS) describes a severe brain injury in which: Arousal is present, but the ability to interact with the environment is not. Eye opening can be spontaneous or in response to stimulation General responses to pain exist, such as increased heart rate, increased respiration, posturing, or sweating Sleep-wakes cycles, respiratory functions, and digestive functions return There is no test to specifically diagnose Vegetative State; the diagnosis is made only by repetitive neurobehavioral assessments. Persistent Vegetative State (PVS) Persistent Vegetative State (PVS) is a term used for a Vegetative State that has lasted for more than a month. The criteria is the same as for Vegetative State The use of this term is considered controversial because it implies a prognosis.
Minimally Responsive State (MR) Minimally Responsive State (MR) is the term used for a severe traumatic brain injury in which a person is no longer in a coma or a Vegetative State. Persons in a Minimally Responsive State demonstrate: Primitive reflexes Inconsistent ability to follow simple commands An awareness of environmental stimulation The frequency and the conditions in which a response was made are considered when assessing the meaningfulness or purposefulness of a behavior. Akinetic Mutism Akinetic Mutism is a neurobehavioral condition that results when the dopaminergic pathways in the brain are damaged. Damage to these pathways results in: Minimal amount of body movement Little or no spontaneous speech Speech which can be elicited (For example, the person can answer a question if asked, but otherwise does not voluntarily start saying anything). Eye opening and visual tracking Infrequent and incomplete ability to follow commands Vigilance and agitation for Frontal Akinetic Mutism Akinetic Mutism is different from the Minimally Responsive State because the lack of movement and speech with Akinetic Mutism is not because of neuromuscular disturbance. Locked in Syndrome Locked in Syndrome is a rare neurological condition in which a person cannot physically move any part of the body except the eyes. The person is conscious and able to think. Vertical eye movements and eye blinking can be used to communicate with others and operate environmental controls. Brain Death Brain death can result from a very severe injury to the brain. When brain death occurs, the brain shows no sign of functioning. The physician performs a specific formal brain death examination.