Traumatic Brain Injury

AMNESIA

Memory problem due to brain dysfunction (not normal aging) Not attributable to other perceptual or cognitive disturbances Retrograde amnesia o loss of memory for events that occurred prior to the injury Anterograde amnesia - o difficulty remembering events that occurred after the brain injury; this is the most common memory problem Post-traumatic Amnesia (PTA) - o period of time from the injury to the point at which ongoing memory for events becomes fairly stable; o duration of PTA is better predictor of long-term outcome than the duration of loss of consciousness

Responses to Look For:

No response - o The patient does not produce any kind of response to stimuli. Reflexive response - o The patient responds involuntarily. These are repetitive gross body movements. Generalized response - o Inconsistent and non-purposeful response to stimuli in a non-specific manner. Likely to be delayed. Localized response - o Specific but inconsistent reactions to stimuli. Responses are likely directly related to the stimuli. May be more consistent than a generalized response. Purposeful response - o Patient show response that is purposeful to stimuli

Dangerous Signs & Symptoms of a Concussion

One pupil larger than the other. Drowsiness or inability to wake up. A headache that gets worse and does not go away. Slurred speech, weakness, numbness, or decreased coordination. Repeated vomiting or nausea, convulsions or seizures (shaking or twitching). Unusual behavior, increased confusion, restlessness, or agitation. Loss of consciousness (passed out/knocked out). Even a brief loss of consciousness should be taken seriously. concussion management- immediate rest followed by step by step resumption of activities

working memory

People register new info and can repeat it/recreate it without rehearsal or manipulation during first several seconds after they experience it Terms also used to describe this stage o Attention o Short term memory o Primary memory o Immediate memory Time frame = 0-30 seconds

Treatment of Severe TBI

Persistent Vegetative State & Minimally Conscious Purpose of tx: increase responsiveness to environment Facilitate return to consciousness

Gustatory

Prescribed to stimulate taste and produce a response such a lip smacking or salivation. During routine mouth care, a gloved finger can be used to massage the gums and buccal cavity. Various flavors, as well as hot and cold stimuli can be presented. Oral feedings should not be attempted until cough, gag and swallowing reflexes are present. It should be noted that sucking and rooting are primitive rather than purposeful reflexes.

Memory

The ability to store, retain, and recall information and experiences Not a unitary process Memory process involves 4 sequential, interrelated stages o Attention to the information o Encoding, organizing & maintaining the information in working memory o Consolidating or storing information into long term memory o Retrieval of consolidated information as needed

Agitation

The act of agitating or the state of being agitated Disturbance of the mind which shows itself by physical excitement o a state of restless activity such as pacing, moving extremities, wanting to be moving in w/c or walking, crying or laughing without apparent reason observed in at least 1/3 of patients with a TBI who are in the early stages of recovery patient is in the state of PTA and in which excesses of behavior include some combination of aggression, disinhibition, and/or emotional lability Agitated patient's may try to o Remove tubes & monitoring devices o Get out of bed/chair o Remove restraints, o unlock w/c breaks or wheel themselves about with no concern for safety o Some may Scream or shout spontaneously Attempt to kick, bite, hit any persons who come within range Some may be physically or verbally abusive Agitated Behavior Scale (ABS) - Corrigan, 1989 1 = Absent 2 = present to a slight degree 3 = Present to a moderate degree 4 = Present to an extreme degree

Blast injuries

The four basic mechanisms of blast injury are termed as primary, secondary, tertiary, and quaternary. o Characterized by anatomical and physiological changes from the direct or reflective over-pressurization force impacting the body's surface.

Stimulation approach:

The process used to increase arousal and awareness in the patients who have limited ability to interface with his/her environment. Involves the senses o Tactile o Gustatory o Olfactory o Auditory o Visual o Kinesthetic Pt is repeatedly exposed to stimuli, usually in several 10-15 minute intervals

Change Over Time

There is a tendency for memories of information to change over time This is something we all experience with regard to our childhood memories It may explain why we forget some things and have distorted memories of others

Visual

These techniques elicit tracking of objects, responsiveness and attention to visual stimuli. It is usually begun when the patient's eyes open spontaneously and the blink reflex is present. Use of a flash light, overhead light, moving objects slowly in the patient's visual field, mobile are all possible stimuli

General pattern of recovery

Unresponsive Responsive Agitated Non-agitated Confused Oriented Inappropriate Appropriate Automatic Purposeful

Tactile Stimulation

Used to encourage an awareness of sensation. Touch has been demonstrated to promote wellness. Various textures, lotions and degrees of tactile pressure can be applied during bathing. Family is encouraged to stroke and caress the patient. Varying textures can be rubbed along the face, hands and arms.

Physical problems

Weakness or paralysis Poor balance and/or coordination (ataxia) Decreased endurance Abnormal muscle tone, stiffness Problems with motor planning Diplopia Dizziness Seizures Body regulatory deficits Dysarthria** Dysphagia**

Olfactory

Activates limbic system, which is associated with strong emotions. May be difficult in early stages of recovery, as nose and face are often occluded by endotracheal or nasal-gastric tubes. Various odors can be introduced, such as coffee, perfume or spices. Expose pt to pleasant (perfume, coffee, flavor extracts) and unpleasant (garlic, mustard, vinegar) for short intervals (e.g., 10 seconds at a time)

Poor Consolidation

Consolidation = combination of 2+ things If we are not organized, we can't combine/consolidate the info Which leads to less efficient processing and subsequent forgetfulness If we do not use or practice the memory, this may lead to more rapid decay

What is memory?

Learning o Initial perception and acquisition of new information Retention o After info is learned, it is stored/retained for a period of time o The info lasts minutes - months - years . . . . Retrieval o Accessing info that has been stored thru o active recall - conscious attempts to search for/find a name or word o less active - recognition; act of knowing something despite conscious lack of recollection

Intense Stimulation

May be needed for those in a deep coma Pt's in deep coma response to intense stimulation with: o Increased respiration rate o Withdrawal o Increased muscle tension o Grimaces, grunts, unintelligible vocalizations

Auditory

May elicit attention to sound, pitch, change of tone and location of sound. These stimuli should be presented with little environmental noise. It is important that staff and family call the patient by name. Family should be encouraged to talk to the patient, as their voices are familiar to the patient.

ge Related Changes in Memory

altho' more than 75% of adults report difficulty with their memory, fewer than 40% actually show memory impairments retrieval of recently learned info is the most common aspect of memory to show decline with aging WHY? Learning versus retrieval If difficulty d/t retrieval, performance would be helped by cues or multiple choice Older adults can learn new info and retain it but cannot as easily retrieve it freely Why? Reduced resources Speed, energy and attention are reduced Older adults are slower at processing info than younger adults Therefore info that must be deliberately processed will be disproportionately affected as compared to automatic (Implicit) processing tasks Why? Depth of processing If material is processed less completely or in a shallow manner at first, memory will be degraded from the outset, less permanent and more difficult to retrieve Lesson - teach them strategies to process which will help recall

TBI Prognostic Indicators

1. Duration of Coma 2. Duration of Post-Traumatic Amnesia

ABS

1. Short attention span, easy distractibility, inability to concentrate 2. Impulsive, impatient, low tolerance for pain or frustration 3. Uncooperative, resistant to care, demanding 4. Violent and/or threatening violence toward people or property 5. Explosive and/or unpredictable anger 6. Rocking, rubbing, moaning, or other self- stimulating behavior 7. Pulling at tubes, restraints, etc. 8. Wandering from treatment areas 9. Restlessness, pacing, excessive movement 10. Repetitive behaviors, motor, and/or verbal 11. Rapid, loud, or excessive talking 12. Sudden changes of mood 13. Easily initiated or excessive crying and/or laughter 14. Self-abusive, physical, and/or verbal

Types of Brain Herniation

1. Subfalcine Herniation: (1) The cingulate gyrus is pushed laterally away from the expanding mass and herniates beneath the falx cerebri. 2. Transtentorial (Uncal) Herniation: (3) Due to the cerebral edema, the uncus of the temporal lobe (medial temporal lobe) herniates downward into the posterior fossa. 3. Central herniation (2) occurs when there is downward pressure centrally and can result in bilateral uncal herniation. 4. Tonsillar Herniation: (4)If there is also edema or hemorrhage causing swelling in the cerebellum, the tonsil (or tonsils) of the cerebellum herniates downward into the foramen magnum.

post trauma continued again

Although there are no definite answers, a VERY ROUGH guideline is three times as long as they were in coma. What other behaviors can I expect to see in a person in post-traumatic amnesia? Many pts exhibit other neurobehavioral symptoms: Agitation Confusion Disinhibition Lethargy Emotional lability (bouncing from one emotion to another) Motor overactivity (restlessness) Physical or Verbal aggression PTA = severity of TBI < 5 minutes = minor 5-60 minutes = mild 1-24 hours = moderate 1-7 days = severe > 28 days = profound

clinical signs and symptoms

loss or decreased consciousness loss of memory before the event or after neurologic defects- muscle weakness,loss of balance,change in vision or speech/language alteration in mental state-confusion, disorientation,slowed thinking, difficulty concentrating

closed TBI

non penetrating

Traumatic Brain Injury

nondegenrative acquired injury from physical force to the head.

cerebral edema- secondary consequences of TBI

o Accumulation of fluid is brain's generic response to a wide variety of conditions (e.g., trauma, anoxia, infection, inflammation) o Fluid may accumulate o between brain & skull o In the ventricles o In brain tissues o This causes the brain tissues to swell o Almost always develops around primary site of brain injury o But may appear far from primary site of injury o Is a common consequence of diffuse injuries as in translational trauma o Is an important cause of increased intracranial pressure o Usually become significant within 4-6 hours after injury & peak in 24-36 hours

o Subdural hematoma (SDH)

o Accumulations of blood beneath dura mater above arachnoid o SDH are 2x as common as EDH 60% mortality o Most common cause = MVA o Most caused by laceration of veins rather than arteries - most commonly injury to bridging veins that travel from cerebral cortex to dura mater o Acute SDH usually develop with in a few hours & almost always appear within a week of injury o If not controlled, the combination of increasing pressure & displacement of brain tissue by expanding hematoma may lead to coma and death within few hours o Chronic SDH Common in older patients & people with chronic alcoholism Both have increased risk of falling & "some degree of brain atrophy with resultant increase in size of subdural space" o Often the injury that precipitates the hematoma seems trivial (e.g., falls & bumps head) o The hemorrhage gradually fills the subdural space o Eventually the hematoma reaches a size in which is produces symptoms that wax/wane.

o Epidural hematoma

o Accumulations of blood between dura mater & skull o Most caused by skull fx that lacerate arterial channels in the bone o 90% are the result of skull fx MVA Falls Sports injuries o Mortality 20%-30% of pt's with epidural hematomas die as consequence of head injury Strongly related to whether bleeding is from artery (85% of deaths) or a vein (15%) Usually marked by massive hemorrhage with symptoms progressing rapidly, often culminating in death within few hours Venous bleeding usually follows a less dramatic course, with slow progression of symptoms o Magnitude of symptoms from EDH Depends on location of hemorrhage. Bleeding into posterior inferior epidural space can cause compression on brain stem, leading to respiratory distress, decreased heart rate & increased blood pressure Bleeding into frontal & superior epidural space likely to be less serious b/c centers for vital functions are far away & there is more epidural space to accommodate the hematoma before it begins to displace brain structure o Common tx for EDH Surgical removal Practical b/c hematoma's location just beneath the skull

Quaternary

o All explosion-related injuries, illnesses, or diseases not due to primary, secondary, or tertiary mechanisms. o Includes exacerbation or complications of existing conditions. o Any body part may be affected. o Types of Injuries Burns (flash, partial, and full thickness) Crush injuries Closed and open brain injury Asthma, COPD, or other breathing problems from dust, smoke, or toxic fumes Angina Hyperglycemia, hypertension

Unique/Special Populations- children 0-19

o Approximately 145,000 children/adolescents are living with substantial & long lasting limitations in social, behavioral, physical or cognitive functioning follow a TBI o However these numbers likely underestimate true consequences of pediatric TBI given unreported mild TBI, concussion or abusive head trauma o TBI in children can contribute to: Physical impairments Lowered cognitive & academic skills relative to developmental expectations Deficits in behavior, socialization & adaptive functioning Specific impairments in language, memory, problem solving, perceptual-motor skills, attention & executive functions o Time reveals wounds . . . In pediatric populations, some effects of a TBI may not be present initially but can emerge later in a child's development This delay of onset can manifest itself in later academic failure, chronic behavior problems, social isolation & eventually difficulty with employment, relationship and the law o Common behavioral representations in children Lack of inhibition Difficulty reading social cues (pragmatics Emotional lability Above is often attributed to other causes ranging from lack of motivation & laziness to bad parenting

• Older Adults (> 75 years)

o Approximately 775,000 older adults live with long term disability associated with TBI Often attributed to aging process rather than an injury, preventing affected seniors from being accurately diagnosed & treated o Higher risk for mortality Worse functional outcomes than younger patients with similar injuries o Societal & Medical-care costs More extensive for older adults Longer hospital stays Slower rates of functional improvement during inpatient rehab Preexisting medical conditions were also found to increase length of stay among older adults in outpatient rehab

Foregoing consequences of TBI

o Are the result of forces exerted on the brain at the time of the injury = Primary consequences o Caused by mechanical effects of compression, stretching, shearing, abrasion, & laceration of the brain & meninges o Usually followed by Secondary Consequences

How important is ATTENTION following brain damage?

o Attentional disorders are recognized as one of the most common problems associated with brain injury. o Attentional problems are o known to influence the ability to remember o are the foundation upon which ALL other thinking & problem solving skills are based. o If attention is compromised, o information is not properly processed by the brain, o will likely result in reduced understanding & misuse of the information. o it is important to ensure that attention/concentration is enhanced to allow the brain to perform the more complex thinking processes. o Attentional problems can affect the following functions: o Thought processes impulsivity, perseveration, memory problems o Social judgment egocentricity, social withdrawal, frustration, aggressiveness, uncooperativeness o Self-awareness lack of insight, denial, unconcern o Communication being too concrete or literal in interpretations, lack of initiation, difficulties with language comprehension, lack of understanding of overall topic of discussion, failure to use environmental cues, writing & reading disorders

Secondary Consequences of TBI

o Brain's physiological response to trauma or failure of other somatic functions o Are more devastating than primary consequences o No statistics available but it is likely that more people die from secondary consequences than from physical damage suffered at the time of the accidents o *Death rates from TBI are highest in 1st three days with 50%-75% of deaths occurring within 72 hours o Cerebral Edema o Traumatic Hydrocephalus o Elevated Intracranial pressure o Ischemic brain damage o Alterations in blood-brain barrier

• Rural Geographic Residents

o Incidence of TBI-related disability is higher than in urban/suburban areas (24% compared with 15% & 14% respectively) Less likely to have access to specialized trauma care & rehab professionals Fewer recourses exist in rural communities to support independent living after TBI o Transportation limitations Rural residents travel 2-3x further for specialty care, attend fewer medical visits (even with community resource are available) Have less access to medical specialists PCPs are likely to be single source of care for people with TBI related disability with no advanced training

Medical Management of ICP

o Increases blood oxygen levels which causes cerebral arteries to constrict, decreasing cerebral volume to provide temporary reduction in ICP o Steroids o Anti-inflammatory medications reduce cerebral swelling o Hypothermia o Lowering pt's body temperature to diminish swelling o Diuretics o Medication to increase excretion of fluids o Medically Induced Coma o Decreases cerebral metabolism, & constricts cerebral blood vessels o Last resort surgical removal of swollen brain tissue

axonal degeneration

o Is a diffuse process o Affecting some axons in a region and leaving others untouched, creating a spotty pattern of deafferentation (loss of input to a neuron in from other neurons) o This means that the neurons in the region of injury may lose only part of their synaptic inputs from other neurons

non acceleration injury

o Is caused by a slow moving object with large surface area o The skull may be forced from its customary oval shape to a more nearly circular shape (ellipsoidal deformation) o Change in shape increased skull's volume b/c circular containers have more volume than ovoid containers o Increased volume reduces pressure in cranial vault, with greatest pressure reduction in regions closest to the skull o As a result, tissue deep in brain (corpus callosum & basal ganglia) expand outward into regions of less pressure o The expansion stretches & shears brain tissues & blood vessels causing bleeding & swelling inside the brain o Fx at the base of the skull are more dangerous than fx higher up Basal skull fx may damage cranial nerves or carotid arteries, endangering the person's life o Any skull fx is dangerous if meninges are torn (bleeding & potential for infections) o The presence of skull fx does not predict the severity of brain damage

Differences between persistent and permanent

o It's important to stress the difference between persistent & permanent vegetative state o often abbreviated identically as PVS o When the term "persistent vegetative state" was first described, it was emphasized that persistent didn't mean permanent and it is now recommended to omit "persistent" and to describe a patient as having been vegetative for a certain time. o When there is no recovery after a specified period (depending on etiology 3-12 months) the state can be declared permanent and only then do the ethical and legal issues around withdrawal of treatment arise.

severe DAI

o May lead to vegetative state o Pt has sleep-wake cycle but makes no purposeful movement, does not talk, does not follow instructions & does not track visual stimuli o Vegetative state is a sign of severe diffuse damage to cortical & subcortical tissues with relative sparing of the brain stem Abrasions & Contusions o On the underside of the brain are common in acceleration injuries o Walls & roof of cranial vault are smooth but the floor is uneven and has sharp edges, especially under the frontal lobes o As the brain moves in skull during acceleration & deceleration, it scrapes along the bottom surfaces of the frontal lobes & anterior temporal lobes o Parietal, occipital & convexities of frontal lobe are spared b/c the inner surface of the cranial vault is smooth & featureless o Most common areas for brain contusions

Elevated Intracranial Pressure (ICP)

o Most dramatic & deadly consequence of TBI is pressure build-up inside skull. o Heightened pressure is caused by o Cerebral edema o Traumatic hydrocephalus or o Hemorrhage o Elevated ICP is most frequent cause of death from TBI o Monitoring & controlling ICP is primary concern from medical mgt standpoint o The brain is remarkably tolerate of modest increases in pressure, provided it is distributed equally o TBIs create pressure gradients in which pressure is greatest in/around site of injury & decreases with increasing distance from injury o Pressure gradients push brain tissues away from regions of high pressure into areas of low pressure o Brain tissues are distorted, stretched, compressed & forced against partitions in skull usually with ominous consequences Most dangerous consequence of ICP is HERNIATION o Brain tissue is pushed around rigid partitions in cranial vault or extruded thru cranial orifices

Duration of Coma

o Relationship between duration of coma following severe TBI & eventual recovery o Longer durations of coma are associated with poorer eventual outcomes Coma "Severity" Levels: Severe over 6 hours Moderate less than 6 hours Mild 20 minutes or less

secondary blast injury

o Results from flying debris and bomb fragments o Any body part may be affected o Types of Injuries Penetrating ballistic (fragmentation) or blunt injuries Eye penetration

tertiary blast injury

o Results from individuals being thrown by the blast wind o Any body part may be affected o Types of Injuries Fracture and traumatic amputation Closed and open brain injury

• Military Service Members & Veterans

o Since the beginning of Operation Enduring Freedom & Operation Iraqi Freedom in early 2000s, public health & health care communities have become aware of increased rate os TBI among active duty US military personnel o Congress passed TBI Act of 2008 Requires CDC & NIH in consultation with DoD & VA to determine how best to improve collection & dissemination of info related to incidence & prevalence of TBI among people formerly in the military Provide recommendations on development & improvement of TBI diagnostic tools & treatments o While current military & veterans are a population of concern All new cases of TBI (80%) occur in non-deployed settings MVA, falls, sport & recreation, assaults o May also sustain TBIs during training activities (DVBIC, 2013; MSMR, 2013) o Combat Zones TBI sustained in conflict zones also contribute to other problems (e.g., post-traumatic stress disorder) Those with both PTSD & mild TBI are at greater risk for post-concussive symptoms than those with just PTSD along or TBI alone PTSD, pain conditions, mood disorders & substance use/above can yield symptoms similar to those of mild TBI (e.g., difficulty sleeping) making differential diagnoses challenging.

Late - oriented but with high level cognitive-linguistic deficits

Goal is for pt to become maximally independent and lean how to compensate for and adjust to residual deficits

memory again

Memory - another way to view it Immediate Memory o Acquisition of new info o Attention & Encoding / Working Memory Recent Memory o Retention of info over time o Long term memory (for dx, 30-60 minutes) Remote Memory o "old" info Recognition Memory o "Forced choice" - do you recognize "it"? - yes/no

ways to test different modalities

Modality Stimulus Items Auditory Banging items together; Ring bells; Music; Loud whistle; Familiar voices; telephone ringing; Knock on door; Calling name; General conversation; Television/radio Tactile Temperatures; Touch (fur, silk, feathers, sandpaper, corduroy); Pressure; Vibration Visual Flashing/bright lights; Bright colors; Moving objects; Flashcards Olfactory Familiar fragrance; Citrus; Coffee; Flowers; Peppermint; Spices; Garlic Taste Swabs (peppermint/lemon); Lemon juice; Mustard; Salt; Soy sauce; Sugar; Lollipops Kinesthetic ROM exercises; Roll side to side; Alternating movements; Raise arms/legs

Causes of TBI

Number 1 cause:falls account for 40% of injuries. Over all 55% for children and 81% in adults over 65. Number 2 cause: unintentional blunt force. 15% of TBI Number 3 cause: motor vehicle accidents. 14% Number 4 cause: assults. 10%. More occurring in children * Men likely to to get it then women. Over 3 times greater. Highest amoung elderly

Early - Coma / Low Level of Consciousness- recovery

Only generalized responses to environmental stimuli and some simple stimuli-specific responses (e.g. visual tracking, localizing, following 1 step commands)

Middle - confusion / disorientation/ agitation

Pt's alertness and increased activity have increased but they're still very confused They require moderate but systematically decreasing levels of support to succeed in simple ADL

The point at which memory is consolidated & learned so that it lasts more than a few seconds Time frame = 30 seconds to several days

Recent Memory

Collateral Sprouting (or dendritic proliferation)

Repair process" o Intact axon terminals adjacent to regions of limited deafferentation may send fibers into regions of deafferentation o May at least partially explain physiologic recovery in pt's with mild-to-moderate TBI o Pt's with severe TBI may have lost too many axons to permit meaningful recovery related to deafferentation

classification of TBI severity

TBI Classification GCS Duration of Coma Length of PTA Severe 3-5 > 6 hours Over 24 hours Moderate 9-12 < 6 hours 1-24 hours Mild 13-15 < 20 minutes 60 minutes or less

Severity of TBI & Physiologic Consequences

The nature & severity of neuropathology caused by TBI determines the nature & severity of pt's symptoms & the extent of their recovery Range of Severity Concussion Coma least severe most severe Least severe TBI = Concussion

Penetrating injuries

caused by missiles and bullets, blunt instruments, and sometime falls. Damage caused from missiles depend on velocity. High velocity can perforate the skull, and carry foreign material into the brain. Low velocity is less dangerous.

Causes among ages

falls for 65 and older motor vehicle crashes for 5-25 years of age assult for ages 0 to 4. * falls remain the leading cause of death except for 15-24 year olds

penetrating injuries continuted

o Some low-velocity impacts o May cause penetrating injuries if the force is concentrated in a small enough area (e.g., being struck on the head with a club OR striking the head on the table edge in a fall) o These injuries may fracture (fx) the skull If the fx is severe, bone fragments may be pushed into the brain Brain tissue may be cut, torn, & bruised o Low-velocity penetrating injuries o Between 20%-40% of low-velocity penetrating injuries cause death Although mortality is greater (up to 90%) for penetrating injuries caused by handguns If pt survives 1st day, then infection, bleeding, & increased intracranial pressure caused by brain swelling becomes important threats to pt's survival o Penetrating injuries o That affect the brain stem usually are fatal b/c of damage to structures that regulate respiration, heart rate, blood pressure and other vital functions o Adults who survive penetrating head injuries o & concomitant physiologic consequences are almost always left with physical, cognitive & linguistic impairments o These impairments (except for those caused by high-velocity missiles) usually are focal rather than diverse & they reflect the loss of functions served by the damaged brain tissue

coup injuries ( blow or impact)- liner injuries

o Stationary head resists acceleration but in a few milliseconds, the head begins to move away from the point of impact o The brain has its own inertia, it remains motionless for a few milliseconds after the head begins to move o This inertial lag compresses the brain against the inside of the skull at the point of impact causing bruising & abrasions on the surface of the brain

Minimally Conscious State

o Subcategory of patients above the vegetative state but unable to communicate consistently. o To be considered as minimally conscious: o Pts have to show limited but clearly discernible evidence of consciousness of self or environment, on a reproducible or sustained basis, by at least one of the following behaviors: following simple commands, gestural or verbal yes/no response (regardless of accuracy), intelligible verbalization, purposeful behavior (including movements or affective behavior that occur in contingent relation to relevant environment stimuli and are not due to reflexive activity). o Emergence from Minimally Conscious State o defined by the ability to use functional interactive communication or functional use of objects o Further improvement is more likely than in vegetative state patients o However, some remain permanently in a minimally conscious state

Traumatic Hydrocephalus- secondary cause

o Swelling of brain tissues sometime compresses the passage thru which CSD circulates among ventricles & into subarachnoid space o Trapped CSF exerts pressure on walls of ventricles causing them to expand o This raises intracranial pressure

pathophysiology of TBI

o TBI is the result of an external mechanical force applied to the cranium and the intracranial contents, leading to temporary or permanent impairments, functional disability, or psychosocial maladjustment. o TBIs can be: o "Open" (aka Penetrating) o Involving penetration of dural (outermost meningeal layer) covering of brain o "Closed" (non-penetrating) o Primary mechanism of damage is blunt blow to head or rapid changes of skull motion o Both associated with acceleration/deceleration forces acting on the brain

contre coup- linera injuries

o The brain, now compressed against the skull, rebounds and accelerates to match the rate at which the head is moving o Within a few milliseconds, the head abruptly stops moving (either b/c it strikes an object or b/c of the tethering action of the vertebrae & neck muscles) o The momentum of the brain keeps it in motion for a few more milliseconds & it becomes compressed against the skull opposite the point of impact, causing bruises & abrasions opposite to the blow that started the head moving

shaken baby syndrome- liner injuries

o The same physical processes operate when the head is moving at a constant rate of speech in a linear path & is suddenly stopped o The combination of violent shaking & the child's weak neck muscles cause child's head to bounce to/fro, causing diffuse acceleration injuries to child's fragile brain tissue

Post-Traumatic Amnesia (PTA)

o The time following coma/unconsciousness during which pt is unable to store new information & experiences in memory o Duration of PTA is inversely related to pt's eventual level of recovery from TBI o PTA lasting less than 2 weeks was associated with good recovery in 80% of cases o No pt with PTA longer than 12 weeks made a good recovery o Levin, O'Donnell, & Grossman (1979) o Developed Galveston Orientation & Amnesia Test (GOAT) Designed to track recovery of orientation & memory for TBI pt's who are emerging from coma Consists of 10 questions to assess pt's ability to remember & reproduce biographic information (orientation to person), pt's orientation to place & time and the pt's memory for events immediately preceding or following injury Pt begins GOAT with 100 points • Points are subtracted for each failed test item • Scores o WNL 80-100 o Borderline 66-79 o PTA 0-65 Useful screening tool for getting a general idea of pt's level of cognitive functioning & responsiveness

primary blast injury

o Unique to HE, results from the impact of the over-pressurization wave with body surfaces o Gas filled structures are most susceptible - lungs, GI tract, and middle ear. o Types of Injuries Blast lung (pulmonary barotrauma) TM rupture and middle ear damage Abdominal hemorrhage and perforation Globe (eye) rupture- Concussion (TBI without physical signs of head injury)

Glasgow Coma Scale (GCS

o Universal "screening" o based on 15 point scale for estimating and categorizing the outcomes of brain injury on the basis of overall social capability or dependence on others o initially used to assess level of consciousness o now used by first aid, EMS, and doctors as being applicable to all acute medical and trauma patients. o Scoring o Ranges from 3 (lowest) to 15 (highest) based on eye opening, verbal response, best motor response o "3" - indicates likely fatal damage, especially if both pupils fail to respond to light and oculovestibular responses are absent. o Higher initial scores tend to predict better recovery GSC Severity Ratings 14 or 15 is mild TBI 9 to 13 is moderate TBI 3 to 8 is severe TBI

acceleration injuries

o When the TBI is caused by sudden acceleration or deceleration of head o The brain & brain stem often suffer DIFFUSE damage caused by movement inside the skull. o The movement is caused by inertia forces generated either: o when the head is moving rapidly thru space & comes to a sudden stop (strikes floor after a fall) o When head is at rest & suddenly accelerated (struck by blunt object) o Accelerations injuries take 2 forms depending on direction from which head is struck

Vegetative State

o can also be observed in the end-stages of some chronic neurodegenerative diseases, such as Alzheimer's o (however recent studies show that most of these patients are rather minimally conscious), o and in anencephalic infants o absence of a major portion of the brain, skull, and scalp that occurs during embryonic development

o Ischemia

o is a restriction in blood supply o cerebral ischemia = is a condition in which there is insufficient blood flow to the brain to meet metabolic demand o This leads to poor oxygen supply or cerebral hypoxia and thus to the death of brain tissue or cerebral infarction / ischemic stroke. o Ischemic Brain Damage o Most pt's with TBI sustain some ischemic brain damage in addition to damage caused by tissue destruction, swelling & displacement o Etiology o Physical injury to heart & lungs May compromise respiratory & cardiac output leading to diminished blood oxygenation & reduce blood supply to brain o Elevated ICP Squeezes blood vessels reducing the volume that reaches the brain o Cerebral Vasospasm Decrease carrying capacity of blood vessels especially when cardiac output is reduced o Cerebral Ischemia o Far more prominent in pt's with severe TBIs than in pt's with mild-mod TBI o Distribution of ischemia varies but damage is most common in basal ganglia and watershed cortical regions adjacent to the distributions of 3 major cerebral arteries (where small-diameter arteries resist blood flow) o 2 types of ischemia: o focal ischemia which is confined to a specific region of the brain; o global ischemia which encompasses wide areas of brain tissue. o Cerebral Vasospasm o Contraction of the muscular layer surrounding blood vessels o Occurs in 15%-20% of TBIs o Cortical arteries that are inflamed by presence of blood from SAH most frequently affected (altho' any artery may be affected) o May also be caused by injury to control centers that regulate dilation/constriction of cerebral blood vessels OR by chemical/metabolic disruptions o Rarely responsible for major neurologic complications o However when vasospasm is inflicted on system already compromise by other consequences of brain injury, it may contribute to significant worsening of pt's condition. o Alterations in Blood-Brain Barrier o In addition to tissue destruction, neuronal disorganization & vascular changes previously discussed, TBI also induces changes in blood-brain barrier o Blood-brain barrier normally regulates the movement of substances from the blood into tissues of the brain o Brain injury disrupts the regulation, allowing normally excluded substances (proteins, neurotransmitter chemicals) to enter brain tissue o More severe TBI, are more likely to disrupt the blood-brain barrier than are less severe injuries o The passage of normally excluded substances into brain may contribute to accumulation of fluid & swelling of brain tissue (cerebral edema)

Dx of Vegetative State

o very unlikely when there is consistent & reproducible visual fixation or any degree of sustained visual pursuit - the diagnosis of a minimally conscious state then becomes much more likely. o It is essential to establish repetitively the formal absence of any sign of conscious perception or deliberate action before making the diagnosis

open TBI

penetrating dural layers

Risk factors

substance abuse age sex Causes in intoxicated people-mva, falls, assult Substance abuse & MVA • Drivers 16-44 are 3-4X more likely to be legally intoxicated at time of fatal accident than people over 45 • Male drivers involved in fatal MVA are 2x as likely to be intoxicated as female drivers

Brain injury statistics

• In 2010, about 2.5 million emergency department (ED) visits, hospitalizations, or deaths were associated with TBI—either alone or in combination with other injuries—in the United States. o TBI contributed to the deaths of more than 50,000 people. o TBI was a diagnosis in more than 280,000 hospitalizations and 2.2 million ED visits. These consisted of TBI alone or TBI in combination with other injuries. • Over the past decade (2001-2010), while rates of TBI-related ED visits increased by 70%, hospitalization rates only increased by 11% and death rates decreased by 7%. • In 2009, an estimated 248,418 children (age 19 or younger) were treated in U.S. EDs for sports and recreation-related injuries that included a diagnosis of concussion or TBI. o From 2001 to 2009, the rate of ED visits for sports and recreation-related injuries with a diagnosis of concussion or TBI, alone or in combination with other injuries, rose 57% among children (age 19 or younger).

Summary of people at higher risk for TBI

• Young people • Low-income individuals • Unmarried individuals • Members of ethnic minority groups • Residents of inner cities • Men • Individuals with a history of substance abuse • Individuals who have suffered a previous TBI

hemmorages

bleeding

variables related to recovery

Age Substance Use/Abuse Age Older pt's with TBI have higher mortality Mortality of people 60+ are approximately 2x than of pt's 20 or younger Older pt's more likely to suffer hemorrhages which are also likely to be larger Older pt's recover less rapidly & are more likely to exhibit persisting confusion, attentional impairments & memory impairments than younger pt's Making older pt's more likely to remain dependent on caregivers Substance Use/Abuse Alcoholic pt's experience longer intervals of coma, lower levels of consciousness after emerging from coma, longer hospitalizations & greater impairments in memory & verbal learning than nonalcoholic counterparts o This can be partially explained by physiologic consequences of alcohol intoxication at time of injury More likely to experience cerebral hypoxia, hemorrhage or cerebral edema Substance Use/Abuse Effects of substances other than alcohol abuse have received little empiric study Presumably chronic drug use would have similar negative effects Other patient-related variables = Minor effects on recovery Education Intelligence Socioeconomic status People with more education, higher intelligence & higher SES seem to recover better than those with low education, low IQ and low SES Patient Related Variables Premorbid personality disorders & emotional disturbances may also negative affect recovery Pt's with maladaptive personality characteristics & premorbid emotional instability have a somewhat poorer prognosis than those without such disturbances

non delcarative

Allows one to learn w/o having conscious awareness of having learned o Aka Implicit Memory o implied, rather than expressly stated o AKA Procedural memory not based on the conscious recall of information, but on implicit learning. is primarily employed in learning motor skills and should be considered a subset of implicit memory. It is revealed when one does better in a given task due only to repetition - no new explicit memories have been formed, but one is unconsciously accessing aspects of those previous experiences. involved in motor learning depends on the cerebellum and basal ganglia

Common Problems after TBI

Altered levels of consciousness (already discussed) Physical problems Cognitive-Linguistic Behavioral Emotional

Mild-Moderate TBI

As pt's orientation improves, communicative-cognitive impairments become more obvious & assessment becomes more practical Persons with TBI (or BI in general) o Exhibit a confusing mix of communicative-cognitive impairments o No 2 BI persons exhibit the same combination of impairments BUT o Consistent patters DO exist

Orientation

As pt's with severe TBIs return to consciousness & begin responding to environmental stimuli, most remain profoundly disoriented, confused and agitated. Primary purpose at this stage is to establish baseline measure of orientation & memory Orientation o Awareness of self and appreciation of how one relates to others or to the environment o Major problem in severe TBI o Person - knowledge of who he/she is; who others are o Place - knowledge of where he/she is o Time - knowledge of year, month, date, day of week, hour, plus sense of passage of time Orientation - Assessment o GOAT - can be given daily o Orientation Log (O-Log) http://www.tbims.org/combi/olog/olog.pdf Orientation Tx of confused &/or agitated pt's combines environmental control to: o Reduce confusion & disorientation o Control maladaptive behavior Response contingencies to directly manage behavior are used along with pharmacologic management to facilitate new learning/relearning. Orientation training o Becomes the focus of intervention as pt's confusion/awareness diminish & they respond to caregivers/family o Relies on environmental prompts placed in pt's living space, verbal prompts, orientation drills and behavior mgmt. Environmental prompts: - help pt anticipate upcoming events & assume responsibility for daily routines o Signs o Notes o Calendars o Appointment slips / therapy schedule o Clocks o Pictures of pt & family Orientation drills o Passive drill SLP provides instruction, demonstrations, prompts & cues to help pt understand who they are, what happened to them, where they are and to current time. o Active drill Pt is given responsibility for carrying out ADL that depend on concepts of person, place & tie

Assessment

Assessment focuses on alertness & responsiveness to stimulation o Via Behavioral Assessment Provide a structured approach that permits and/or facilitates o Monitoring and documentation of neurological and cognitive recovery o Monitoring of the efficacy of pharmacologic, environmental, and behavioral interventions o Communication among the rehab team, and a framework for team conferences Behavioral Assessments . . . o Identify the patient's sensory, physical, and cognitive strengths, enabling maximization of communication and consistency of responses o Identify the patient's weaknesses, enabling further intervention o May prove able to help elucidate prognosis and/or serve as an early marker for neuro medical changes Behavioral Assessment of Minimally Responsive Patients 1. Western Neuro Sensory Stimulation Profile (WNSSP) 2. Coma Recovery Scale-Revised (CRS) 3. Coma/Near Coma Scale (CNC)

Cognitive-Linguistic

Attention/concentration Memory Organization/sequencing Problem solving/reasoning Information processing (speed & efficiency) Anosagnosia Communication d/t language and/or pragmatic deficits

Displacement

Because short-term memory has a capacity of only 5-9 items, any new items of information will tend to replace those already there Thus if too much information is presented prior to processing into long-term memory, then it is likely that forgetting will occur

Acoustic Stim

Can also include talking to pt about familiar people, places & event Reading using material pt enjoys Playing their favorite music

observed symptoms of TBI

Can't recall events prior to or after a hit or fall. Appears dazed or stunned. Forgets an instruction, is confused about an assignment or position, or is unsure of the game, score, or opponent. Moves clumsily. Answers questions slowly. Loses consciousness (even briefly). Shows mood, behavior, or personality change

Content-dependent Memory

Classification by information type Involves info stored in long term memory 2 broad categories o Declarative o Non-declarative

Post-Concussion Ramifications

Considerable controversy with regard to long-term implications of concussion. o On one end of the spectrum, some claim that repeated concussions cause a neuro-degenerative brain disease called chronic traumatic encephalopathy or CTE. o On the other end of the spectrum, some claim that there are no significant long-term sequelae of concussion. The murky evidence lies somewhere in between Post-Concussive Syndrome (PCS) Chronic Neurobehavioral Impairment Depression Chronic Traumatic Encephalopathy (CTE)

Post-Traumatic Amnesia (PTA) continued

Defined as the period of time (minutes, hours, days, weeks, or months) after the injury when the patient exhibits a loss of day-to-day memory. During PTA o The patient is unable to store new information and therefore has a decreased ability to learn. o Events that occur during PTA never get stored in long-term memory; therefore things that happened during that period cannot be recalled. o The patient's ability to learn new information is minimal or nonexistent. o pt may be told that they have been in a car accident, and a few minutes later, they may not be able to recall that information. Early in PTA o pts may not be aware of being in a hospital & may instead state that they are at home or work. o When they say they are at home or work instead of the hospital, this is called CONFABULATION. It is important to keep in mind that the person is not lying, but rather they are confused. Confabulation o The unconscious filling of gaps in one's memory by fabrications that one accepts as facts. Later in PTA o Pt's confabulate less, but still have trouble retaining memories of specific episodes. o E.g., they may not recall that they had visitors the previous day. After emerging from PTA Pt's usually have a permanent memory gap for events during the entire period of PTA and/or coma, or their memories from this time may be "sketchy" (recall some events and not others). We have even heard patients describe this time as "like being in a dream." Even after someone has emerged from PTA o that person may continue to have difficulty learning new information. This is called ANTEROGRADE AMNESIA. o In addition they may have trouble recalling information that happened prior to the accident. This is called RETROGRADE AMNESIA.

Emotional

Depression & mood swings Agitation, paranoia, irritability, rage Flatness, apathy Anxiety, panic attacks Lack of emotional regulation Quick anger, heightened sensitivity Post-Traumatic Stress Disorder

Remote Memory

Describes the oldest memories including historical facts and childhood recollections Time frame = days to years

Nature & Severity of TBI

Determined by nature & severity of TBI Persons who have "lost" large amounts of brain tissue often experience impairments of basic processes plus impairments of higher-level cognitive-linguistic skills. Persons with localized or patchy brain injuries are likely to experience impairments in high level cognition Location matters too! o Cortical injuries are more likely to affect higher level processes than subcortical injuries o Frontal lobe injuries characteristically cause problems with regulation and initiation of purposeful behavior o Posterior language-dominant hemisphere injuries characteristically cause problems with comprehension/production of language

Kinesthetic

Done to promote awareness of oneself in relation to space. Also enhances balance. Range of motion (ROM) will encourage awareness of extremity movement and prevent complication of immobility. Family can cuddle and rock the patient. A tilt table can be used, or patient can be rocked from side to side.

Sensory Memory

Essential 1st step for learning any new info If you cannot perceive/recognize the info to be remembered, the process of memory will be derailed from the start Time frame = less than 2 seconds

Trace Decay

Essentially, information leaves a physical trace or change in the memory structures which fades over time. If a piece of information stored in memory is not used or not considered important, it will disappear This may happen quickly or weeks/months/years

Information Processing

Generalized term that incorporates those functions that enable the brain to deal effectively and efficiently with sensory and other information Two important aspects o speed of thinking o capacity How important is Information Processing? It affects the ability to perceive, discriminate, sequence, chunk and categorize information to previously learned information Affects both auditory and visual stimuli Sequencing problems occur and appear as an inability to follow a logical sequence of steps or inability to logically order information chunking problems are demonstrated by an inability to match and sort info as well as an inability to attach meaning to sequenced information categorization results in inability to place info into categories of relatedness a reduction in IP speed limits the capacity or amount of info a person can process which leads to deficits in alternating/divided attention Jobs a person could have done prior to TBI now require or exceed IP capacity and lead to overload and fatigue. Or tasks that could be completed under test or structured conditions are frequently failed in real-life situations Then concentration difficulties, HA and irritability are reported

Symptoms reported by patients

Headache or "pressure" in head. Nausea or vomiting. Balance problems or dizziness, or double or blurry vision. Bothered by light or noise. Feeling sluggish, hazy, foggy, or groggy. Confusion, or concentration or memory problems. Just not "feeling right," or "feeling down".

Interference

If we are too distracted or if too much information is being presented, this may lead to interference between the competing pieces of information

Sensory Stimulus

Increase pt's alertness/arousal Increase pt's response to the environment Facilitate changes in responsiveness such as increased consistency & specificity of response &/or decreased latency of response

Coma Recovery Scale-Revised (CRS-R)

Initially in 1991 but was restructured and republished in 2004 as the JFK Coma Recovery Scale-Revised (Giacino, Kalmar and Whyte, 2004). The purpose of the scale is to assist with differential diagnosis, prognostic assessment and treatment planning in patients with disorders of consciousness. Consists of 23 items that comprise six subscales addressing auditory, visual, motor, oromotor, communication and arousal functions. CRS-R subscales are comprised of hierarchically-arranged items associated with brain stem, subcortical and cortical processes. The lowest item on each subscale represents reflexive activity while the highest items represent cognitively-mediated behaviors. Scoring is standardized and is based on the presence or absence of operationally-defined behavioral responses to specific sensory stimuli. Scores of 0-14 are considered "minimally responsive"; scores of 15-25 or high indicate "emergent awareness". Correlation with outcomes have been documented as stronger for changes in CRS scores than for initial, one-time scores

Most Severe Coma

characterized by the absence of arousal & consciousness. state of unarousable unresponsiveness in which the patient lies with the eyes closed and has no awareness of self and surroundings. A comatose patient will never open the eyes even when intensively stimulated. The patient lacks the spontaneous periods of wakefulness and eye-opening induced by stimulation that can be observed in the vegetative state. Persistent Vegetative State o Patients in a vegetative state are awake but are unaware of self or of the environment o Oxford English Dictionary o to vegetate is to "live merely a physical life devoid of intellectual activity or social intercourse" o vegetative describes "an organic body capable of growth and development but devoid of sensation and thought". "Persistent vegetative state" o has been arbitrarily defined as a vegetative state still present one month after acute traumatic or non-traumatic brain damage but does not imply irreversibility "Permanent vegetative state" o denotes irreversibility. o Multi-Society Task Force on PVS concluded that: 3 months following a non-traumatic brain damage and 12 months after traumatic injury, o the condition of vegetative state patients may be regarded as 'permanent' and therefore irreversible. Permanent Vegetative State o These guidelines are best applied to pts who have suffered diffuse traumatic brain injuries and post anoxic events; o other non-traumatic etiologies may be less well predicted & require further considerations of etiology & mechanism in evaluating prognosis. o Even after these long & arbitrary delays, some exceptional patients may show some limited recovery. o This is more likely in patients with non-traumatic coma without cardiac arrest, who survive in VS for more than 3 months.

Behavioral

confabulation apathy lack of awareness (anosagnosia) Restlessness/agitation Impulsivity Inability to delay gratification Inappropriate social skills Inappropriate sexual behavior Inertia, lack of motivation Magnification of pre-existing personality Slow work speed Denial Inflexibility

Western Neuro Sensory Stimulation Profile (WNSSP)

developed to assess cognitive function in severely impaired head-injured adults (Rancho levels II-V) and to monitor and predict change in slow-to-recover patients. Slow-to-recover patients are those who remain at Rancho levels II and III for extended periods of time and are candidates for sensory stimulation programs. Consists of 32 items in 6 areas, for a total score of 1-113 which assess patients' arousal/attention, expressive communication, and response to auditory, visual, tactile, and olfactory stimulation. Can be a useful tool for studying the recovery process and evaluating treatment programs for slow-to-recover patients.

Coma/Near Coma Scale (CNC)

developed to measure small clinical changes in patients with severe brain injuries who function at very low levels characteristic of near-vegetative and vegetative states. designed to provide reliable, valid, easy, and quick assessment of progress or lack of progress in low-level brain injured patients. The CNC essentially expands the levels of the Disability Rating Scale (DRS) that incorporate the vegetative and extreme vegetative categories. The CNC has five levels, based on 11 items, that can be scored to indicate severity of sensory, perceptual, and primitive response deficits.

Posttraumatic Stress Disorder (PTSD)

is more common in mild to moderate TBI. Why? o Because they may remember more of the actual accident. o Those with severe TBIs have no recall of the accident, & usually no recall of a time before & after the accident. The last thing they may recall is a day or two before the accident & then waking up in the hospital some time later. Therefore, they were UNAWARE that they were in a life-threatening situation.

Post-Concussion Syndrome

not truly a 'syndrome' because there is no core of consistent symptoms no clear correlation with type or severity of concussion, biomarkers, or genetic/personality predisposition. Symptoms include neurologic (e.g. dizziness, light sensitivity), cognitive (memory, attention deficits) and emotional (depression, anxiety). individuals should not simply be relegated to prolonged rest, which may perpetuate the symptomatology.

Ranchos Los Amigos Scale (RLAS)

provides convenient way to characterized TBI pt's cognitive & behavioral recovery Developed in 1979 (Hagen & Malkamus) o To provide more comprehensive estimate of cognitive & behavioral characteristics than previous measures o Provided standard set of 8 categories to which pt's could be assigned according to their arousal, responsiveness, restlessness, attention, memory & executive ability Revised Version RLAS-R o Revised by Hagen in 1997 o Added 2 categories and 7 levels reflecting pt's levels of independence o Most institutions are using RLAS-R RLAS-R Total Assistance Level 1-3 Maximal Assistance Levels 4-5 Moderate Assistance Level 6 Minimal Assistance Level 7 Stand-by Assist Level 8 Stand-by Assist on Request Level 9 Modified Independent Level 10

Declarative Memory

requires conscious recall some conscious process must call back the information. It is sometimes called explicit memory, since it consists of information that is explicitly (clearly developed or formulated) stored and retrieved. Declarative memory can be further sub-divided into o Semantic Memory facts taken independent of context allows the encoding of abstract knowledge about the world, such as "Paris is the capital of France". o Episodic memory concerns information specific to a particular context, such as a time and place. used for more personal memories, such as the sensations, emotions, and personal associations of a particular place or time.

Concussion ICD-10 Criteria

a history of TBI and the presence of 3 or more of the following 8 symptoms: (1) headache, (2) dizziness, (3) fatigue, (4) irritability, (5) insomnia, (6) concentration or (7) memory difficulty, and (8) intolerance of stress, emotion, or alcohol. Findings may include the following: Headache - o most common symptom of PCS. The specific type is variable. One study found a prevalence of persistent posttraumatic headache in 15.3% of patients with minor head injury compared to 2.2% of matched minor injury ED controls. Cranial nerve symptoms and signs - o Dizziness (2nd most common symptom), vertigo, nausea, tinnitus, blurry vision, hearing loss, diplopia, diminished sense of taste and smell, light and noise sensitivity Psychological and neurovegetative problems - o Anxiety, irritability, depression, sleep disturbance, change in appetite, decreased libido, fatigue, personality change Cognitive impairment - o Memory impairment, diminished concentration and attention, delayed information processing and reaction time

hematomas

accumulation of blood

non penetrating brain injuries

o Can be divided into 2 general categories o Non-acceleration injuries Produced when the restrained head is struck by a moving object o Acceleration injuries Produced when unrestrained head is struck by a moving object or when moving head strikes stationary object Also occur when rapidly moving head abruptly changes direction w/o striking a surface (e.g., whiplash injury, shaken baby) o Non-Acceleration Injuries o Usually cause less severe brain injuries than acceleration injuries o Blows to a moving head are up to 20x more devastating than blows to a fixed head o Primary consequences related to deformation of skull by impact of object striking skull: o The skull is "slightly" elastic so a blow to the head deforms the skull inward causing localized damage to meninges & brain cortex at point of impact o Basilar skull fx o breaks in bones at the base of the skull, require more force to cause than cranial vault fractures. o Thus they are "rare", occurring as the only fracture in only 4% of severe head injury patients. o Basilar fx have characteristic signs: blood in the sinuses; CSF leaking from the nose or ears; raccoon eyes (bruising of the orbits of the eyes that result from blood collecting there as it leaks from the fracture site); and Battle's sign (caused when blood collects behind the ears and causes bruising).

Chronic alcohol use

o Cause a vitamin deficiency. o b/c the digestion system of alcoholics is unable to absorb vitamin B-1 (thiamine), a syndrome known as "Wernicke's Encephalopathy" may develop Characterized by impaired memory, confusion & lack of coordination. o Further deficiencies of thiamine can lead to "Korsakoff's Syndrome." Characterized by amnesia, apathy and disorientation. o Widespread disease of the brain is a feature of both Wernicke's and Korsakoff's Syndromes.

o Coup & Contrecoup injuries

o Cause focal damage to meninges & brain tissue where the brain is compressed against the skull o The combination of coup & contrecoup injuries is called translational trauma o Only occurs with linear acceleration & deceleration of head o More likely following blows to front/back of head than blows to side of head b/c the space between brain & skull (epidural space) is greater at the front/back than at sides o The potential for linear brain movement inside the skull is greater when head moves front-to-back than side-to-side

angular acceleration injuries

o Caused by blows that strike the head off-center, causing it to rotate & move at an angle away from the point of impact o The brain's inertia keeps it at rest when head begins to move o The mismatch in rotational acceleration creates twisting forces in axial structures (midbrain, basal ganglia, brain stem, cerebellum) o Within a few milliseconds, the brain begins to rotate in the same direction as the head o When the head as reached the limit of its range of movement, the tethering action of the vertebrae & neck muscles cause it to rebound in opposite direction o The brain continues its rotation for a few additional milliseconds causing a 2nd episode of twisting forces concentrated in axial structures o Twisting & shearing forces o Tend to be concentrated at the boundaries between gray matter (soft supportive tissue) & white matter (firm fiber tracts) o Tissue damage, bleeding, & swelling affect major nerve tracts in internal capsule, corpus callosum, brain stem o Angular acceleration of head & rotational injury to brain usually produces more severe brain injuries than linear acceleration of the head (cranial contents are not subject to twisting forces) o Cranial nerve injuries are o Common following acceleration injuries o Front-to-back (e.g., falling, striking head) injuries may: stretch & tear olfactory nerve (CN 1) leading to loss of smell Damage CN 3, 4, 6 causing difficulty with eye movements & cause double vision (diplopia) CN 8 = tinnitus (ringing/buzzing in ears)

o Intracerebral Hematoma (ICH)

o Caused by rupture of blood vessels inside brain (intracerebral hemorrhage) o ICH usually develops in subcortical white matter, basal ganglia & brainstem o Occasionally a large ICH bleeds into ventricles causing secondary SAH with devastating effects on the patient o Multiple small ICH Sometimes occurs with DAI caused by translational trauma This often leads to coma & death

o Subarachnoid hematoma (SAH)

o Caused by rupture of pial vessels within subarachnoid space o Rapid accumulation of blood from massive SAH typically causes severe headache & rapid neurologic deterioration with death as common outcome o Slowly accumulating blood in subarachnoid space has less ominous consequences o Pt's with slowly developing SAH may go hears w/o overt symptoms o Little is known about long-range consequences of such slowly progressing SAH altho' they are known to contribute to cerebral vasospasm

Areas of the brain involved in ATTENTION

o DAI = generalized slowing of information processing therefore affecting attention o Basic arousal/alertness is dependent on brain stem; LOC & coma = disruption of brain stem functions o Thalamus appears to perform critical role in alternating/divided attention Brain damage - ATTENTION o Injury to cortex can = generalized as well as focal deficits o Frontotemporal brain injury = difficulties in sustained, focused & alternating o Parietal lobe - especially right hemisphere = unawareness syndromes & neglect

Goals of Assessment

o Development of accurate picture of individual's levels of cognitive, emotional & interpersonal functioning o Including o Areas of spared ability o Ability to carry out everyday activities o Estimation of ability to participate in rehab o Suggestions on most effective means to facilitate learning & cognitive functioning

• Incarcerated Populations

o Estimates of TBI in imprisoned population is 60.3% o In many cases, the illegal acts leading to incarceration, as well as non-compliant prison behaviors & subsequent recidivism may be at least partially influenced by the effects of a TBI o However how and when incarcerated populations experienced a TBI or the circumstances surrounding the injury remains unclear.

o Diffuse Axonal Injury (DAI)

o Forces created by acceleration may stretch nerve cell axons thru-out brain & brain stem o Common in acceleration injuries o Presumed to be responsible for many diffuse cognitive & behavioral impairments o Forces causing axonal injury stretch nerve axons rather than tearing them 2-3 hours after injury, the stretched axons swell & in next several hours (sometimes up to 24 hours) begin to separate The disconnected axonal segments then deteriorate, a process that may not be complete until 2 days post injury o Hard to diagnose unless severe o does not show up well on CT scans or with other macroscopic imaging techniques

o Whiplash injuries in MVA

o Head does not strike a surface but is snapped back & forth, may also cause linear acceleration injuries

linear acceleration injuries

o Head is struck by a force aligned with the center axis of the head o Resting bodies tend to stay at rest b/c of inertia