TBI

Most common causes of TBI

Falls, MVA, sports injuries, assaults, blasts, GSW/stabbing

Non-traumatic causes of TBI

Stroke, tumors, hypoxia/anoxia, poisoning, infection

Most common cause of TBI

Falls

How have causes of TBI changed in recent years?

More falls due to aging population, increased youth sports TBIs, and more motorcycle TBIs after helmet law repeals.

Primary brain injury

Immediate mechanical damage at the time of impact

Examples of primary brain injury

Contusions, lacerations, diffuse axonal injury, diffuse vascular injury, cranial nerve shearing, pituitary stalk tearing

Secondary brain injury

Delayed, evolves over hours-days; often causes long term deficits

Examples of secondary brain injury

intracranial hemorrhage, edema, ischemia, neurochemical cascades causing neuronal death

Normal ICP

0-10 mmHg

Abnormal ICP

20 mmHg

Neurological dysfunction and impaired electrical activity occurs when cranial pressure reaches?

40 mmHg

Fatal cranial pressure

60 mmHg

Why is external ventricular drain (EVD) important?

Used to relieve ICP, requires strict head-positioning precautions

Focal

Localized injury

Examples of focal injury

Contusion, hematoma, laceration

Diffuse

Widespread injury, often from acceleration-deceleration forces

Example of diffuse injury

Diffuse axonal injury

Penetrating injury

Open injury, dura mater breached

Examples of penetrating injury

GSW

Non-penetrating injury

Closed injury, no breach of dura

Example of non-penetrating injury

Fall, MVA

Coup

An injury occurs directly under the site of impact

Countercoup

An injury that occurs opposite of the site of impact due to rebound of the brain 

Symptoms of concussion

Confusion, amnesia, delayed responses, disorientation, slurred speech, incoordination, mood changes, possible loss of consciousness

Concussion Grade 1

Confusion <15 min, no loss of consciousness

Concussion Grade 2

Confusion >15 min, no loss of consciousness

Concussion Grade 3

Definite loss of consciousness

Mild brain injury guidelines suggest _________ resolves within 24 hours

Mental confusion including amnesia

Mild brain injury guidelines _______ less than 30 minutes

Loss of consciousness

Up to ____ of TBIs are mild

85%

Hematoma

An accumulation of blood in response to active bleeding

Contusion

Brain bruise due to damaged blood vessels and may require surgery

Laceration

Tearing of brain tissue from rotational forces against skull ridges

Hemorrhage

Active bleeding

Epidural hematoma

Between the dura and bone

Subdural hematoma

Between the dura and arachnoid

Subarachnoid hematoma

Between arachnoid and brain

Intracerebral hematoma

Within the brain tissue

Diffusal axonal injury

widespread axonal shearing from acceleration-deceleration; often devastating (coma, vegetative state, death)

Cognitive complications post TBI

Impaired attention, memory, executive function, language/communication, perception

Behavioral complications post TBI

Agitation, aggression, impulsivity, depression, anxiety, suicidal ideation, poor insight

Physical/system complications post TBI

Integumentary: pressure sores, skin breakdown

HEENT: tracheal granulomas, vocal cord paralysis, dysphonia, bruxism

GI: ulcers, aspirations, bowel incontinence

Cardiovascular: arrhythmias, hypertension, DVT, tachycardia

Genitourinary: neurogenic bladder, urinary retention, fecal incontinence

Endocrine: pituitary dysfunction, thyroid/growth hormone changes, electrolyte imbalances

MSK: fractures, nerve injuries, heterotopic ossification, complex regional pain syndrome

Frontal lobe

Executive functions: ideation, planning, motivation, judgment, personality, working memory

Orbital frontal cortex: emotions, inhibition

Expressive language: Broca’s area (left posterior inferior frontal gyrus)

Primary Motor Cortex: motor execution

Temporal lobe

Emotion (humor)

Memory: visual (right), verbal (left)

Interpretation of music

Receptive language: Wernicke’s area (left)

Parietal lobe

Tactile reception and recognition

Visual-spatial functions (right)

Praxis and motor sequencing (left > right)

Occipital lobe

Primary visual cortex: visual reception

Visual association area: recognition of shapes and colors

Cerebellum

Coordination and balance (e.g., walking)

Brainstem

Breathing

Blood pressure regulation

Arousal / wakefulness