Traumatic Brain Injury

Zara Melikyan, Ph.D.Fall 2015

Lecture Plan• TBI problem significance• TBI causes• Definitions: TBI, concussion, DAI• TBI mechanism• TBI classification• TBI symptoms• TBI diagnosis• TBI treatment, rehabilitation• TBI prognosis• TBI prevention

TBI Problem Significance

• TBI is a major social, economic, health problem

• Major cause of death and disability

– Epidemiology in the US• 52,000 deaths• 1.5 million head injuries reported in ER• 5.3 million (2%) with TBI-related disabilities• Moderate & severe head injury associated with increased

risk of AD

TBI Problem Significance

– Mostly affects children and young adults

– Males > females sustain TBI

– Milder cases undiagnosed and untreated

– May cause long-lasting/disabling deficits

TBI Causes• Falls (e.g., construction)• Vehicle accidents• Violence, abuse• Sports• War

Definitions

• Traumatic brain injury = intracranial injury – injury to the brain

• Head injury – injury to the brain + other parts of the head (i.e. scalp, scull)

• Concussion – (from “concutere” = shake violently) most common type of TBI

• Diffuse axonal injury – brain injury, damage to white matter, brain tracts

TBI Mechanism

External force injures the brain:

• Sudden acceleration/deceleration within the cranium– Impact– Blast waives– Penetration

• Impact + acceleration

TBI Mechanism

• Contact – head struck by smth – focal injuries• Non-contact – moving brain within the skull –

diffuse injuries– E.g. shaken baby syndrome

• Coup injury – injury under the site of impact

• Counter-coup injury

TBI Mechanism

• Type of force• Direction of forces• Intensity of forces• Duration of forces

Types of forces:• Angular• Rotational• Shear• Translational

Lecture Plan• TBI problem significance• TBI causes• Definitions: TBI, concussion, DAI• TBI mechanism• TBI classification• TBI symptoms• TBI diagnosis• TBI treatment, rehabilitation• TBI prognosis• TBI prevention

Primary and Secondary TBI

• Primary injury – damage that occurs at the moment of trauma (tissues and blood vessels stretched, compressed, torn)

• Secondary injury – biochemical cascade of events minutes – days following injury:– Alterations in cerebral blood flow: ischemia, hypoxia– Edema– Changes of pressure within the scull– BBB damage

TBI Classification• Severity

• Injury mechanism– Closed/non-penetrating/blunt– Penetrating

• Anatomical features of the injury

GCS PTA LOCMild 13-15 <1 day 0-30 minModerate 9-12 1-7 days 30min-24 hoursSevere 3-8 >7 days >24 hours

Assessment of Level of ConsciousnessGlasgow Coma Scale

Eyes opening Verbal Motor1 Does not open No sounds No movements

2 In response to pain Incomprehensible sounds Extension to pain3 In response to voice Inappropriate words Abnormal flexion to

pain4 Spontaneously Confused, disoriented Withdrawal to pain5 N/A Normal Localizes painful

stimuli6 N/A N/A Obeys commands

InterpretationSevere GCS <8-9Moderate GCS 8 – 9-12Minor >=13

Levels of Consciousness

Level Summary Metaconscious Monitor and control own cognitive

processes. Prefrontal cortexConscious Normal. Orientation X3 (self, place,

time). SleepConfused Disoriented, slow to orient, difficulty

following instructionsDelirious Disoriented, restless, agitated,

hallucinations, delusions

Levels of ConsciousnessLevel Summary

Somnolent Sleepy, drowsy, slow and disorganized response to stimuli

Obtunded Decreased alertness, slow responses, sleepiness, decreased interest in surroundings

Stuporous Sleep-like state, no spontaneous activity, respond only to painful stimuli

Comatose Can not be aroused no response to stimuli. No corneal/gag reflex, may not have pupillary response to light

First/Transient Symptoms After TBI

• Loss of consciousness (LOC)• Headache• Vomiting• Nausea• Dizziness• Balance problems• Lack of motor coordination• Lightheadedness• Blurred vision• Tinnitus (ringing in ears)• Fatigue, lethargy• Change in sleep pattern

Longer Lasting Impairments Following TBI

• Physical – Damage of the brain – intra-axial– Damage in the skull but outside of the brain – extra-axial– Swelling (edema)– Increased intracranial pressure– Hematoma (blood collection): epidural. subdural– Hemorrhage (bleeding): subarachnoid, intraventricular– Focal lesions

• Orbitofrontal cortex• Anterior temporal lobes

– Diffuse injury - DTI

Longer Lasting Impairments Following TBI

• Cognitive– Memory: PTA, short-term memory– Language– Executive function: decision making– Alexithymia

• Motor• Social• Emotional (regulation)• Behavioral

Diagnosis

• Neurological examination• Neuroimaging– Computerized tomography (CT)– Magnetic resonance imaging (MRI)

• Neuropsychological testing of cognitive, emotional, behavioral changes after TBI

Normal Brain Imaging

TBI Brain Imaging

TBI Brain CT - Hematoma

TBI Brain CT – Intracerebral Hemorrhage

TBI Brain CT – Subarachnoid Hemorrhage

TBI Brain CT – Diffuse Axonal Injury

TBI Brain Imaging

TBI Treatment & Rehabilitation

• Acute stage, “golden hour”:– Stabilize: O2, blood flow, ICP– Prevent further injury• Surgery• Medications• Rest• Prevent seizures

TBI Treatment & Rehabilitation

• Subacute, chronic stages:Multidisciplinary team: impatient/outpatient– Neurology– Psychiatry– Physical therapy– Speech therapy– Recreation therapy– Occupational therapy– Cognitive rehabilitation– Counseling– Supported employment

Prognosis

• The more severe the injury the worse the prognosis

• Permanent disability:– Mild injuries – 10%– Moderate injuries – 66%– Severe injuries – 100%

TBI Prevention

• Protection from accidents: belts, helmets• Changes in sports practice – helmets• Environmental changes – For elderly: grab bars in bathroom, rails; remove

tripping hazards– For children: safety gates, shock-absorbing surfaces

• Safety education• Enforcement of law• Abuse prevention

Thank you!