Transcript TBI - Brain & Cognitive Sciences

OVERVIEW
• INTRODUCTION
• THE NEUROPSYCHOLOGY OF TBI
• NEUROREHABILITATION OF TBI PTS.
• PRACTICAL/CLINICAL MANAGEMENT ISSUES
IN TBI REHABILITATION AND CARE
TBI Epidemiology
• Incidence - ~200 per 100,000 in the U.S. a year
• General Demographics - peak at ages 15-24; 34X greater frequency in males.
TBI - Major Causes
• Motor vehicle
accidents
• Personal violence
• Falls
Why Neuropsychology?
• Brain-behavior relationships can be quite
complex. Often, there is more than “what meets
the eye.”
• The neuropsychologist, who is trained in
observing, assessing, and understanding brainbehavior relationships, can assist other
professionals in clarifying and organizing what
they see clinically.
Pathology of Head Trauma
• focal injury
• diffuse axonal injury (DAI)
• superimposed hypoxia/ischemia
• diffuse microvascular damage
Medical Complications
Include:
edema
contusion
laceration
vascular lesions (hemorrhages, hematomas)
infections
cranial nerve injury
focal cerebral lesions
Blood Vessels of the Skull
The brain requires a rich blood
supply, and the space between the
skull and cerebrum contains many
blood vessels.
These blood vessels can be
ruptured during trauma, resulting in
bleeding.
Groove for middle
meningeal artery
Coup/Contre-coup Injury
A French phrase that describes
bruises that occur at two sites in
the brain.
When the head is struck, the
impact causes the brain to bump
the opposite side of the skull.
Damage occurs at the area of
impact and on the opposite side of
the brain.
Epidural Hematoma
An epidural hematoma is a blood
clot that forms between the skull
and the top lining of the brain
(dura).
This blood clot can cause fast
changes in the pressure inside the
brain.
When the brain tissue is
compressed, it can quickly result
in compromised blood flow and
neuron damage.
Subdural Hematoma
A subdural hematoma is a blood
clot that forms between the dura
and the brain tissue.
The clot may cause increased
pressure and may need to be
removed surgically.
When the brain tissue is
compressed, it can quickly result
in compromised blood flow and
tissue damage.
Classifying CHI
Concussion - a mild traumatic brain injury
characterized by a brief loss or change in
consciousness and/or a brief post-traumatic
amnesia.
Classifying CHI (cont’d)
Means of classification:
admission GCS score
length of coma
length of PTA
The Importance of PTA
Post-traumatic amnesia (PTA) - refers to a period
of clouded consciousness which precedes the
attainment of full orientation and continuous
awareness in persons recovering from head
injuries. It can be defined as beginning from the
last clear memory before a head injury to the first
clear memory after.
The Importance of PTA (cont’d)
The Importance of PTA (cont’d)
Understanding Posttraumatic amnesia will help
you know when the patient is still in a fairly
acute stage of recovery, with accompanying
cognitive/behavioral symptoms.
Understanding PTA will also help you to
estimate the severity of the head injury.
The Importance of PTA (cont’d)
PTA
GCS
Mild
0-1 hr
13-15
Moderate
1-24 hrs
9-12
Severe
> 24 hrs
<8
Understanding Diffuse/Nonspecific
Vs.
Focal Neurocognitive Sequelae of
TBI
Diffuse Axonal Injury
Brain injury does not require a
direct head impact. During rapid
acceleration of the head, some
parts of the brain can move
separately from other parts. This
type of motion creates shear
forces that can destroy axons
necessary for brain functioning.
These shear forces can stretch
the nerve bundles of the brain.
Diffuse
Axonal
Injury
The brain is a complex network of
interconnections. Critical nerve
tracts can be sheared and
stressed during an accelerationtype of injury.
Diffuse axonal injury is a very serious
injury, as it directly impacts the major
pathways of the brain.
Diffuse or Nonspecific Sequelae of TBI
- diminished arousal/alertness
- impaired attention/concentration
- slowed information processing
- concrete thinking
- poor insight
- fatigability
Interior Skull Surface
The base of the skull is rough, with
Bony ridges
many bony protuberances.
These ridges can result in injury to
the frontal and temporal lobes of the
brain during rapid acceleration or
deceleration.
Injury from contact
with skull
Temporal Lobe
The temporal lobe plays a
role in emotions, and is also
responsible for smelling,
tasting, perception, memory,
understanding music,
aggressiveness, and sexual
behavior.
The temporal lobe also
contains the language area
of the brain.
Temporal Lobe Injury
The temporal lobe of the brain is
vulnerable to injury from impacts of
the front of the head.
The temporal lobe lies upon the
bony ridges of the inside of the skull,
and rapid acceleration can cause the
brain tissue to smash into the bone,
causing tissue damage or bleeding.
NP Sequelae of Temporal Lobe Injuries
- impaired language comprehension
- dysphasia, dysnomia
- impaired learning and memory
- affective changes
anxiety
anger outbursts
irritabiity
depression
Frontal
Lobe
The frontal lobe is the area of the
brain responsible for higher
cognitive functions.
These include:
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Problem solving
Spontaneity
Memory
Language
Motivation
Judgment
Impulse control
Social and sexual behavior.
Frontal Lobe Injury
The frontal lobe of the brain can be
injured from direct impact on the front
of the head.
During impact, the brain tissue is
accelerated forward into the bony
skull. This can cause bruising of the
brain tissue and tearing of blood
vessels.
Frontal lobe injuries can cause
changes in personality, as well as
many different kinds of disturbances in
cognition and memory.
NP Sequelae of Frontal Lobe Injuries
Orbitofrontal deficits:
- emotional/personality disinhibition
- irritability, hypersensitivity
- poor self-monitoring
- impulsivity, inappropriate social behavior
- anosmia
- may appear manic or antisocial
NP Sequelae of Frontal Injuries (cont’d)
Dorsolateral prefrontal deficits:
- “executive”impairments
- cognitive inflexibility, perseveration
- poor cognitive organization, planning
- diminished judgment and insight
- motor programming disturbances
- may appear depressed, avoidant, passive
NP Sequelae of Frontal Injuries (cont’d)
Anterior cingulate or fronto-mesial deficits:
- abulia (lack of initiative/drive)
- akinesia
- indifference
- diminished spontaneity, initiation
- reduced verbal output
- may appear depressed
Parietal Lobe
The parietal lobe plays a
role in our sensations of
touch, smell, and taste. It
also processes sensory and
spatial awareness, and is a
key component in eye-hand
co-ordination and arm
movement.
The parietal lobe also
contains a specialized area
called Wernicke’s area that
is responsible for matching
written words with the sound
of spoken speech.
Occipital Lobe Injury
Occipital lobe injuries occur
from blows to the back of
the head.
This can cause bruising of
the brain tissue and tearing
of blood vessels.
These injuries can result in
vision problems or even
blindness.
III. Neurorehabilitation of TBI
Rehabilitation Terminology
Impairment - a loss or abnormality of structure or function at
the level of tissue or organ that can lead to
disability.
Disability -
the restriction or inability to perform a skill or
activity that results from pathology or
impairment.
Handicap -
a disadvantage for an individual on account of a
disability that prevents the fulfillment of
expected social roles.
What is Rehabilitation?
rehabilitare - to restore, from re-, again; habilis, suitable.
Activities designed to facilitate and maximize recovery of
function following injury. In hospitals, frequently multi- or
inter-disciplinary in nature, and provided by a team consisting
of a physiatrist, neuropsychologist, nurse, speech-language
pathologist, occupational therapist, and physical therapist.
What is Rehabilitation?
Restorative - designed to bring an impairment closer to its
original, premorbid function.
Maintenance - designed to keep functioning at a static level,
despite increasing impairment.
Remember, rehabilitation generally emphasizes function!
Goals of Rehabilitation
• Reduce disability or handicap
• Increase functional independence
• Facilitate adjustment
Approaches to Cognitive Rehabilitation
Restorative Focus:
restoration of specific neuropsychological impairment(s).
Goal:
to exercise and ultimately improve underlying difficulties
rather than symptoms.
Method: isolate/assess impairments; repeated practice on psychometric,
computerized, or paper and pencil tasks believed to exercise
areas of deficit.
Efficacy: questionable. Generalization has not been consistently
demonstrated in studies.
Approaches to Cognitive Rehabilitation
Compensatory Focus:
reducing disability.
Goal:
to teach the brain-injured patient to use strengths, strategies,
and skills to reduce the impact of the impairment.
Method: use of mnemonics and other mediation strategies to deal with
memory impairment; use of memory aids and cueing devices
such as alarms, diaries, timers, calendars, etc.
Efficacy: generally better than restorative approaches. Demonstrated
success with external aids, provided patient is motivated, aid is
relatively easy to use, and are taught to be applied to specific
real life memory difficulties.
Approaches to Cognitive Rehabilitation
Environmental Manipulation Focus:
reducing or avoiding disability.
Goal:
to maximize the patient’s performance by modification of
environmental factors.
Method: alteration/manipulation of patient’s environment. For example,
quieter environment to avoid distraction; alteration of work
duties such that they minimize demands on memory or
initiative; use of external aids or cues for memory problems
(patient more passive relative to same methods used in
compensatory strategies).
Efficacy: lack of well-controlled research to demonstrate efficacy.
IV. Clinical Management Issues in
TBI Rehabilitation
Rehabilitation of TBI Patients:
Some Behavioral/Emotional Challenges
- depression/anxiety
- agitation, irritability, lability
- impulsivity
- impaired motivation
- dependency
Rehabilitation of TBI Patients:
Some Neurocognitive Challenges
- poor insight
- diminished attention/concentration
- impaired learning and memory
- poor planning and organization
- cognitive inflexibility
Managing Neurobehavioral and
Neurocognitive Issues
- family and staff education
- behavioral and pharmacologic intervention
- compensatory strategies/mechanisms
- environmental modifications
- lots of patience