TRAUMATIC BRAIN INJURY (TBI)

TBI definition: “Injury involving the brain resulting from some type of impact and/or acceleration/deceleration

of the brain” (Lezak)

1. Types of Head Injury.

o Open Head/Penetrating head injury. Characteristics: Lacerated scalp; Skull penetrated by an intruding

object; Object lodged in brain; Brain parts are directly damaged; Possible infection and bleeding.

- Prediction of the neuropsychological outcome depends on the following information: Where the penetration

occurred; What was the trajectory; If scattered fragments are present (and if so where exactly in the brain);

How this focal pathology relates to the behavioral outcomes.

o Closed-Head/Blunt-Head Trauma. Characteristics: The skull remains intact; The brain is not exposed

directly to the trauma; Produced by rapid acceleration, followed by deceleration of the head.

o Acceleration: force propels the brain from stationary to moving (being hit by something)

o Deceleration: brain already in motion, and then stops abruptly (most motor vehicle accidents)

o Coup injury: occurs at the site of impact

o Contrecoup injury occurs as a result of the brain ricocheting against the opposite side of the initial

point of impact

2. Types of Brain Damage.

a. Diffuse axonal injury: shearing and tearing

b. Edemas: Swelling of the brain or increased intracranial pressure (ICP). Main cause of death in

moderate and severe head injury.

c. Herniation: downward displacement of the brain caused by edema or by a hematoma (pool of blood) .

Puts extreme pressure on neighboring regions (if brain stem, can cause coma and respiratory failure

leading to death).

3. TBI severity relates to behavioral and neuropsychological outcomes - ranging from cognitive functioning

and personal and social competence to quality of life.

- 3 Levels of severity, based on a behavior-based classification system that considers: 1. Duration of loss of

consciousness (LOC), 2. Initial score on Glasgow Coma Scale (GCS), and 3. Length of Post-Traumatic

Amnesia.

o Glasgow Coma Scale: Measures depth and duration of coma based on 3 types of responses: Motor responses,

Verbal responses, and Eye-opening. Lower score reflects worse functioning. Has good prognostic value.

o Post-Traumatic Amnesia refers to loss of memory or ability to acquire new information for events after TBI.

TBI Prognosis: Severity of Injury is the strongest predictor of recovery after moderate and severe TBI.

Effects of TBI:

- Cognitive effects: Attention & Concentration, Memory, Speed of processing, Confusion, Perseveration,

Language processing, Executive functions

- Emotion effects: Lack of motivation, Irritability, Aggression, Depression, Disinhibition, Emotional lability

- Personality changes: Fluctuating mood, inhibition or disinhibition of aggression or sexuality

- Other effects: Activities of daily living (problems with grooming, eating, etc), Social functioning (loss of power

and control, loss of status, lack of access to services or funding, social devaluation).

Severity Classification

Measure Mild Moderate Severe

Glasgow Coma Scale 13-15 9-12 3-8

Loss of Consciousness < 30 minutes 30 min – 24 hours > 24

hours

Posttraumatic Amnesia < 24 hours 1-7 days > 7 days

Neuropsychological Assessment of TBI

Intelligence: WAIS-R (Age-corrected): Attention/Concentration: Digit Span, Mental Control, WMS, Trails A &

B

Perceptual/Organizational: Rey-Osterrieth Complex Figure Copy, Hooper Visual Organization Test; Sensory &

Motor Exam: Grip Strength, Finger Tapping; Memory: Verbal & Nonverbal (WMS, Rey-Osterrieth); Executive

functions/Frontal Systems: Stroop, Wisconsin Card Sorting, WISC-R Mazes, Design, Fluency; Emotional

status: Beck Depression Inventory

TBI Treatment

1. Immediate emergency care

2. Medication: Anti-seizure drugs, Coma-inducing drugs, Diuretics

3. Surgery: Removing hematomas, Repairing skull fractures

4. Rehabilitation: A multi-stage process, different for each person. Depends on: Severity of initial injury, Rate of

physiological recovery, Functions affected, Resources available to the patient, Areas of function not affected by

TBI.

- Inpatient rehabilitation, Outpatient programs - in clinic or at home/work/community.

- Holistic approaches targeting cognitive, emotional, and/or behavioral deficits, with the goal of enabling patients

to increase their ability to perform activities of daily living and return to school or work (reestablishing

previously learned behavior patterns, establishing new patterns of cognitive activity or compensatory

mechanisms, Mock-ups of functional environments).