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 LOC Mild 13-15 <1 day 0-30 min Moderate 9-12 1-7 days 30min-24 hours Severe 3-8 >7 days >24 hours

Assessment of Level of Consciousness Glasgow Coma Scale Eyes opening Verbal Motor 1 Does not open No sounds No movements 2 In response to pain Incomprehensible sounds Extension to pain 3 In response to voice Inappropriate words Abnormal flexion to pain 4 Spontaneously Confused, disoriented Withdrawal to pain 5 N/A Normal Localizes painful stimuli 6 Obeys commands Interpretation Severe GCS <8-9 Moderate GCS 8 – 9-12 Minor >=13

Levels of Consciousness Summary Metaconscious Monitor and control own cognitive processes. Prefrontal cortex Conscious Normal. Orientation X3 (self, place, time). Sleep Confused Disoriented, slow to orient, difficulty following instructions Delirious Disoriented, restless, agitated, hallucinations, delusions Metaconscious - People who possess the ability to monitor and control their own cognitive processes in addition to meeting all the criteria indicative of a normal level of consciousness. In the field of cognitive neuroscience, metacognitive monitoring and control have been viewed as functions of the prefrontal cortex, which receives sensory input signals from divergent cortical regions and implements control through feedback loops which are established utilizing the underlying mechanisms of neuroplasticity (see chapters by Schwartz & Bacon and Shimamura, in Dunlosky & Bjork, 2008). Conscious - Assessment of LOC involves checking orientation: people who are able promptly and spontaneously to state their name, location, and the date or time are said to be oriented to self, place, and time, or "oriented X3".[8] A normal sleep stage from which a person is easily awakened is also considered a normal level of consciousness.[9] "Clouding of consciousness" is a term for a mild alteration of consciousness with alterations in attention and wakefulness. Confused - People who do not respond quickly with information about their name, location, and the time are considered "obtuse" or "confused".[8] A confused person may be bewildered, disoriented, and have difficulty following instructions.[9] The person may have slow thinking and possible memory time loss. This could be caused by sleep deprivation, malnutrition, allergies, environmental pollution, drugs (prescription and nonprescription), and infection. Delirious - Some scales have "delirious" below this level, in which a person may be restless or agitated and exhibit a marked deficit in attention

Levels of Consciousness 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 Somnolent - A somnolent person shows excessive drowsiness and responds to stimuli only with incoherent mumbles or disorganized movements.[8] Obtunded - In obtundation, a person has a decreased interest in their surroundings, slowed responses, and sleepiness Stuporous - People with an even lower level of consciousness, stupor, only respond by grimacing or drawing away from painful stimuli Comatose - Comatose people do not even make this response to stimuli, have no corneal or gag reflex, and they may have no 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!