|
Return to the Brain Injury
Rehabilitation Services Menu
Variables Contributing to Neurological & Neurobehavioral Recovery
Demographic Variables
- Age at injury: infants can have developmental problems,
young adults recover better that older adults, older adults
have more stable lives and develop effective compensatory
skills.
- Pre-morbid Intelligence and Education Levels: more education
may increase connectivity of neural networks, more practice
of skills during education may also result in more automatization
of cognitive skills.
- Gender: most information comes from the stroke population
with indication that women recover better, new studies indicate
that there some influences come from hormones and hormonal
cycling.
- Cultural Background: multicultural clients are most likely
to end therapy prematurely, language barriers, group identity,
beliefs & values influences.
- Pre-morbid or Current Drug & Alcohol Abuse: TBI population
has a higher rate of drug and alcohol abuse pre-morbidly.
Abuse after injury contributes to a poor outcome
Injury Related Variables
- Time Since the Injury:
- The fastest recovery is in early stages, moderate to
severe injury is slow but significant for the next 2 years.
- Accommodations and compensatory may be developed ANYTIME,
underlying motor skills and cognitive skills of attention
can improve with structured interventions even years after
injury.
- Diaschisis is the name for the mechanism which
explains that undamaged areas don't function. The reason
for the dysfunction is that these undamaged areas are
deprived of neuronal input from and to the damaged area(s).
Diaschisis may explain fastest recovery in early stages
during which these undamaged areas reconnect and start
to function.
- Injury Extent and Severity:
- Severe injuries takes longer to recover than mild injuries.
- A focal injury (in one location) recovers more rapidly
than a diffuse injury (throughout the brain). However,
a small focal lesion can have a significant and long-term
negative impact, if the lesion affects a critical brain
area where compensation is difficult.
- Small lesions can recover function and usually recovery
of the original behavior.
- Large lesions develop original behavior through compensation
and behavioral adaptation to function.
- A prior injury can exacerbate a current injury.
- Recovery of Different Functions at Different Rates:
- Simple, highly familiar, over-learned tasks recovery
faster. Complex, novel tasks recover slower.
- Complex tasks involves multiple underlying and interconnected
skills and more conscious and flexible control.
- Functions of the frontal lobe involve effortful attention,
flexible planning, organizing, and problem solving. These
functions are often among the most persistent impairments
after injury.
- Wernicke's and Broca's aphasias show gradual but incomplete
recovery. Recovery from global aphasia is less.
- Recovery from aphasia after TBI often shows quick and
dramatic recovery.
Psychological Factors:
- Positive Factors
- The rehabilitation process involves an interactive partnership-a
cooperative process between the patient, family, and therapist.
- The entire process is grounded in respect, trust, and
commitment.
- The level of readiness of the patient and family contribute
to success.
- The success of intervention is closely related to the
working relationship of the therapist and patient's family.
- The development of therapeutic rapport is essential.
- Negative Factors:
- Effects of the injury
- Premorbid personality features of patient, family, and/or
therapist
- Problems in negotiating the therapeutic relationship
and treatment plan.
- Depression and anxiety are common on TBI and often result
from the cognitive impairment. Depression and anxiety
further erode cognitive efficiency and can decrease motivation,
contribute to hopelessness, despair, and isolation. In
the long run, these negative emotions have a high potential
to limit personal and social adjustment and community
reintegration.
- The patient is not aware of his/her own deficits. Therefore,
he/she does not recognized the need for treatment and
may be resistant to rehabilitation.
- The aware patient can be resistant to the rehabilitation
process due to his/her conception of rehabilitation as
being coercive and/or manipulative.
- Anger, resistance, and refusals decrease success. In
early stages after injury, behaviorally based interventions
can contribute to making the patient ready for the rehabilitation
process.
Neuroplasticity and Synaptic Reorganization:
- The brain is fundamentally altered in structure and function
by experience.
- Diaschisis refers to remote non-damaged areas that reconnect
to other non-damaged areas and regain function.
- Functional reorganization is a process by which neural circuits
that survive after injury reorganize to accomplish a given
behavior in a different way. This compensation process can
inhibit restitution of function.
- Modification of synaptic connectivity occurs when a person
is learning and having experiences.
- This process occurs in adult brains with and without
injury.
- A neuron that has lost input from a damaged area can
develop new dendrites or dendritic spines to receive information
from undamaged neuron; and to a lesser extent can produce
axonal sprouting.
- This synaptic plasticity is present on both recovery
processes and in normal leaning.
- The variations of rehabilitation experiences affect
the kind and degree of input to damaged circuitry and
therefore influence recovery.
- During restitution, neurons reconnect at the injury
site. During compensation, neurons reconnect in different
or remote circuits.
- Influences on Neural Circuitry
- Structured sensory input can increase connectivity of
partially disconnected neural circuits for a desired behavior.
- Reducing sensory input can decrease connectivity of
neural circuits for undesired behavior.
- In rehabilitation, structured activities are designed
to foster reconnectivity of partially disconnected neural
circuitry.
- The Impact of Interhemispheric Competition
- The right and left hemispheres of the brain are competitive
and serve as inhibitory influences on each other. (Keep
each other in line.)
- After damage to one hemisphere, the inhibitory influence
of the damaged hemisphere on the undamaged hemisphere
is reduced or lost. (The undamaged hemisphere can get
out of line.)
- The damaged circuits can have further loss of function
due to inhibitory competition from the undamaged hemisphere
and thereby reduce the recovery potential of the damaged
circuits.
- Recovery of a function involves activating circuits
in the damaged hemisphere and reducing activation in the
undamaged hemisphere.
- There may be inhibition operating within the injured
hemisphere.
- Bottom-Up versus Top-Down Processes in Rehabilitation
- Bottom-Up processes refer to the provision of perceptual,
motor, or other externally generated or cued inputs to
the damaged networks. Thereby eventually improving higher
functions.
- Top-Down Processes refer to use of "higher"
brain centers to determine what sensory information selected
for further processing. Thereby fostering connectivity
in the damaged circuits.
- Efforts to improve attention and executive functions
may have extensive positive impact on recovery of a variety
of functions.
- Neuroplasticity: Future Directions
- Pharmacological interventions to reduce the biochemical
changes (caused by brain injury) that cause further damage
to neural networks.
- Neural implants (cell grafting) that will stimulate
growth of cells or cell connections that have been damaged.
- Stem cells will become more readily available.
- Gene therapy (gene transfer, gene splicing)
- Neuroplasticity: Guiding Principles
- The brain is a dynamic organ, capable of extensive neurological
reorganization over the lifetime of the individual and
following injury.
- Motor, sensory, and cognitive abilities can and usually
do improve over time, although recovery is generally prolonged
and the sequelae of brain injury usually persist to some
degree.
- Structural changes in the brain, particularly in dendritic
fields and synapses, underlie behavioral changes. There
are many influences on synaptic connectivity.
- Enhanced recovery of neurobehavioral function is associated
with environmental stimulation and the structuring of
experiences in both the normal and damaged brain.
- There is a role for both restitutive and compensatory
approaches in rehabilitation.
- Functional reorganization typically involves recruitment
of areas adjacent to the lesion and in homologous areas
of the contralateral hemisphere.
- Behavioral outcomes reflect a complex interplay of Bottom-Up
and Top-Down processes and of intrahemispheric and interhemispheric
influences.
Factors Related to Training Programs and Interventions
- Recovery is dependent in par on the nature, quality, and
quantity of postinjury experiences.
- There is inadequate information about whether or not rehabilitation
services should be early and intense or less intense but more
prolonged time.
- These are recommendations are particularly important in
early stages of neurological recovery:
- Make sure the patient is adequately rested. REM sleep
may be necessary fir consolidation of learning to take
place. Drugs that interfere with sleep may affect cerebral
plasticity and may retard recovery.
- Be cautionary in choosing pharmacological interventions.
Some commonly used drugs reduce the potential for plastic
changes to the brain. (Diazepam has been shown to impair
plastic recovery.) The use of drugs that reduce the potential
for plastic changes to the brain should be minimized during
rehabilitation.
- Make use of natural windows of increased arousal and
responsiveness. Patients respond best when they are alert
and able to attend to the task at hand. Brief, intermittent
periods of intervention are likely to be more effective
when patients are inconsistently aroused.
- Monitor and control the attentional load on the patient.
Overstimulation can lead to decreased information processing
and reduced awareness of errors. Gradually and systematically
increase attentional load. Provide structured, systematic
stimulation in a hierarchal manner.
- Develop effective cues starting with verbal, tactile,
or visual moving to more subtle and partial cues.
- Distributed practice for short periods is likely to
be more effective than massed practice in a single session.
This is consistent with learning theory and clinical observations.
- Recommendations for when the patient is better able to participate
actively in the rehabilitation process:
- Use shaping and behavioral chaining strategies based
on learning principles.
- Emphasize modifying antecedents and consequences in
behaviorally oriented training. This technique is particularly
relevant to brain injured patients.
- TBI patients are ineffective learners. Identify the
nature of the patient's leaning and memory deficit and
use teaching strategies that are effective for the individual.
Errorless learning reduces errors in the acquisition phase
of learning and improves memory.
- Success breeds success, as well as self-esteem and satisfaction.
Maximize the likelihood of a correct response. Focus attention
to correct responses.
- Work for speed and efficiency of processing and responding
with minimizing error rates.
- Use mental rehearsal and attentional focus to provide
more top-down control. Over self-talk can be used for
self-regulation.
- Identify which deficits do and do not respond to stimulation
based treatments. Attentional skills often respond to
repetition and practice. Episodic memory is less likely
to improve with explicit practice and is managed better
with compensatory approaches.
- Utilize effective generalization strategies in order
for the patient to demonstrate improvements in daily life
in a variety of settings.
Source: Sohlberg, M, and Mateer, C. (2001) Cognitive Rehabilitation.
NY: The Guilford Press.
Return to the Brain Injury
Rehabilitation Services Menu
|
