CDIS 4433 1st Edition Final Exam Study GuideChapter 12: TBI Causes and Consequences- (TBI)Traumatic Brain Injury – aka Craniocerebral Traumao Most common cause of death and disability in the younger populationo Not a stroke, and not caused by the things that cause stroke.o “Traumatic brain injury (TBI), also called acquired brain injury or simply head injury, occurs when a sudden trauma causes damage to the brain.” –National Institute of Neurological Disorders and Strokeo TBI can occur when the head suddenly and violently hits an object, or when an object pierces the skull and enters brain tissue. o Caveat: TBIs are poorly documented, so many are missed or not reported, so the data may be highly inaccurate. o Motor vehicle accidents – 30-50%. o Pedestrian/auto – 15%.o Motorcycles – Very high death and TBI rate. (Helmets help!!)o Alcohol skews the numbers in vehicular accidents – Roughly 1/3 of all motor vehicle accidents involve alcohol. o Falls – second most common cause. Common among elderly and the very young (along with child abuse)o Interpersonal violence – 7% in rural areas, 40% in urban. o Sports – more common in the young because they are more athletic.o Types of TBI Penetrating aka Open Head Injury (Bullets, knives, metal or glass from car body, nail guns, lawn darts (!), etc.)- Occurs when an object pierces the skull and the meninges and enters brain tissue. (injury goes through the layers of the meninges)- Danger of Infection- Penetrating Injury Incidence: 12 per 100,000- Phineas Gague – Most dramatic Open Head Injury – 1948.- Low velocity – less injury (less wave-like displacement in surrounding tissue) – nail gun, knife, low velocity handguns- High velocity – greater injury (brain tissue is injured by shock waves going through the soft matter) – high velocity rifles- Things to consider:o Projectile velocityo Projectile sizeo Projectile fragmentationo Number of wounds (duh!)- Effects of penetrating injuries:o Increased intracranial pressureo Deatho Blood pressure fluctuation o Reduced blood flowo Destroyed brain tissueo Bleeding, infection, swelling, hydrocephaluso Physical, cognitive and language deficits Non-penetrating (injury does not project through the meninges) aka Closed Head Injury – May still cause considerable damage, and the skull may still be fractured, though the meninges not breached. (Blows to the head related to auto accident, sports, falls, etc. in which the skull is not pierced)- ‘Occurs when the skull is not breachedo Concussion, contusion, diffuse axonal injury, and hematoma.- Incidence- Causeso Accidents (soccer ball, football, boxing, MMA, etc.)o Falls o Blunt blow to head (hit with baseball, etc.)o Auto accidents (head hits padded dashboard, etc.)o Abuse or interpersonal violence- Biomechanicso Acceleration/Deceleration – Head moves or stops before the brain, causing the brain to be jammed into the inner surface ofthe skull.  Coup – at site of blow Countrecoup – on opposite side from the blowo Angular Acceleration – Off-center blows can cause the brain totwist within the cranial vault Causes “twisting and shearing” of brain tissue Especially common on the inferior surface where the cranial vault is uneven and irregularo Effects of TBI Laceration or fractures of the skull Diffuse axonal injury (DAI) – Angular blows cause a “twisting” of the brainstem or corpus callosum, tearing axonal pathways. Depending on severity, symptoms may vary greatly. Diffuse vascular injury – tearing of small blood vessels. Primary focal lesions – Specific structures may be injured, resulting in somewhat predictable results. If injuries are specific to Cranial Nerves, the symptoms will be highly predictable. If they are to portions of the basal ganglia, or the cortex, again, symptoms will be more predictable.  Intracranial hematoma – pooling of blood within cranial vault - may be:- Extracranial (under scalp)- Epidural (extradural) (b/w cranial vault and meninges)- Subdural (b/w meninges and cortex)- Intracerebral (within the brin, itself). --- Increased intracranial pressure (May cause symptoms to worsen over time). Pressure cuts off blood flow because the arteries or veins are compressed. Ischemic brain damage – lack of O2 to the brain – (hypoxia) Seizures – Common Infection – Much more common with penetrating injury.o Factors affecting recovery  Duration of Recovery (Rule of spontaneous recovery – 6 months) Severity of injury Other (secondary) injuries Level of consciousness – hard to do tx with comatose patients Duration of coma Pupillary reactivity at admission – gives some indication of extent of brain injury (and location – brainstem?) Age and general health of patient Drug or alcohol abuseo Neurobehavioral Effects Altered consciousness – (Stupor – less severe, Coma – more severe) Survival but in coma state Confusion and disorientation Amnesia (short and/or long term)  Memory problems (similar to amnesia) – may be prior to, or following the trauma Speech disorders  Dysphagia Other neuorlogical symptoms – paralysis, etc Psychiatric changes  Attention deficitso Communication Problems Motor Speech- Apraxia or one of the Dysarthrias Language Problems – (primarily covered in the next chapter) Mutism  Confused language Anomia Perseveration of verbal responses Reduced word fluency Difficulty in initiating conversation Difficulty in turn taking Difficulty in conversational topic selection (inappropriate topics) Problems maintaining conversational topic Lack of narrative cohesion Problems in being concise and direct Difficulty in nonverbal communication Disturbed social interaction Auditory Comprehension problems Problems with reading and writing Dysarthria (35+% of TBI pts exhibit this) – Various types- Hypernasality (Injury to cranial nerves IX and X – glossopharyngeal and vagus)- Impaired rate of speech- Imprecise consonant production- Limited pitch variation (monotone) (prosody)- Reduced breath support for speech- Abnormal stress pattern (prosody)- Reduced phrase length- Reduced speech intelligibility (highly correlated with problems listed above)- Prolonged intervals in speech – (pauses)- Limited variation in