Recent findings regarding recovery from brain injury

Plasticity - Brian Kolb Use of virtual reality Use of smart technology

Brain plasticity Changes that occur in the organization Changes that occur in the organization

of the brain as a result of experienceof the brain as a result of experience

The brain is constantly changing in The brain is constantly changing in response to experience.response to experience.

Those events that alter the normal Those events that alter the normal brain can be recruited to change the brain can be recruited to change the injured brain and, hopefully, stimulate injured brain and, hopefully, stimulate functional improvement.functional improvement.

Changes in neuronal organization Changes in neuronal organization can be shown at various levels of can be shown at various levels of analysis from behaviour to analysis from behaviour to molecules.molecules.

Synapse number can be estimated by Synapse number can be estimated by knowing the length of the dendritic knowing the length of the dendritic fields and the spine density.fields and the spine density.

One key feature is that both measures One key feature is that both measures can go can go up or downup or down with experience - with experience - thus reflecting an increase or decrease thus reflecting an increase or decrease in synapse number.in synapse number.

These changes have implications for These changes have implications for behavioural change.behavioural change..

The cortex is altered by many The cortex is altered by many events including:events including:

1. sensory & motor experience1. sensory & motor experience 2. task learning2. task learning 3. gonadal hormones3. gonadal hormones 4. psychoactive drugs4. psychoactive drugs 5. natural rewards5. natural rewards 6. neurotrophic factors 6. neurotrophic factors 7. ageing7. ageing 8. stress8. stress 9. anti-inflammatories9. anti-inflammatories 10. diet10. diet 11. electrical stimulation11. electrical stimulation

Complex HousingComplex Housing

Brains are larger,Brains are larger,have more connections,have more connections,& the animals have& the animals haveenhanced cognitive &enhanced cognitive &motor behaviourmotor behaviour

BUT, age is critical…BUT, age is critical…

Experiential TreatmentsExperiential Treatments

Complex housing and age Complex housing in adults Increased dendritic length (including old adults) Increased spine

density Heavier brain

Complex housing at weaning Increased dendritic length Decreased spine

density Heavier brain

Complex housing prenatally Decreased dendritic length Increased spine

density Heavier brain

All treatments provide behavioural benefits… They also interact with later plasticity

There are sex differences in connectionsThere are sex differences in connections

Females have more than males in theFemales have more than males in theGRAY areas and Males have more in theGRAY areas and Males have more in theBLUE areasBLUE areas..

Implications Expect sex differences in behaviorExpect sex differences in behavior Expect sex differences in response toExpect sex differences in response to other experiencesother experiences Expect sex differences in response toExpect sex differences in response to brain injurybrain injury Expect sex differences in response to Expect sex differences in response to

treatments.treatments.

Different regions of the brain react differently to medication Psychomotor stimulants all have Psychomotor stimulants all have oppositeopposite

effects in the orbital cortex effects in the orbital cortex compared to compared to the frontal cortexthe frontal cortex

i.e., there is a i.e., there is a decreasedecrease in dendritic length in dendritic length and/or spine density in response to and/or spine density in response to psychomotor stimulants compared to an psychomotor stimulants compared to an increase in the frontal cortex.increase in the frontal cortex.

Thus, the same drug can alter differently Thus, the same drug can alter differently the function of different regions, much like the function of different regions, much like hormones do.hormones do.

Experience Multisensory/motor/social experience

induces widespread synaptic changes in the normal brain.

Thus, such experience should enhance synaptogenesis that will reverse stroke-induced atrophy AND

induce synaptic growth in residual motor areas.

RESULT

1. Complex housing is powerful instimulating functional improvement

But not if only for short periods each day

How do we apply this to brain-injured people?

Best guess is Best guess is intenseintense, multidisciplinary, multidisciplinarytreatments.treatments.

1. Treatments that improve functions:Nicotine; amphetamine (conditionally)Olfactory or tactile stimulationComplex housing ExerciseElectrical brain stimulation NTFs

Summary of ‘Repair’ Treatments

2. Treatments that do not improve functions:Diet (but…)COX-2 inhibitorsRepetitive practice

Summary of ‘Repair’ Treatments

3. Treatments that make functions worse:Fluoxetine (ie., Prozac)social change (stress??)

Summary of ‘Repair’ Treatments

Is plasticity necessarilyIs plasticity necessarily good?good?

1. Shifting functions may interfere with 1. Shifting functions may interfere with other functions.other functions.

2.2. One plastic change may prevent a later one.One plastic change may prevent a later one.

But, remember, the brain is going to change But, remember, the brain is going to change regardless of what we do…regardless of what we do…

ConclusionsConclusions

1. Plastic changes in synaptic organization can support functional1. Plastic changes in synaptic organization can support functionalimprovement after cerebral injury.improvement after cerebral injury.

2. Both pre- and post-injury experience can affect outcome from2. Both pre- and post-injury experience can affect outcome fromcerebral injury. cerebral injury.

4. There are limits to recovery: Animals with high spontaneous4. There are limits to recovery: Animals with high spontaneousrecovery show little benefit from experience or chemicalsrecovery show little benefit from experience or chemicals..

3. A wide range of factors can influence outcome from injury.3. A wide range of factors can influence outcome from injury.

5. There are synergistic interactions between behavioural and5. There are synergistic interactions between behavioural andpharmacological treatments.pharmacological treatments.

Virtual Reality

Uses in neuropsychological assessment and rehabilitation

Dependent on information technology – rapid advances

‘Computer technology is moving from automating the paradigms of the past to creating new ones for the future’

Kruegar 1993

Advantages of VR Ecological validity – can standardise ‘real

life’ tasks rather than relying on artificial tasks

Can simulate virtually any real world environment from a city to a kitchen

Can simulate the tasks people experience in their daily lives (eg food preparation; shopping; banking; office skills; use of public transport; driving

McGeorge et al. 2001 VR Multiple Errands task in a simulated

office (collecting office equipment, preparing refreshments)

TBI did not differ from healthy controls on BADS but were impaired on VR ME

There was a significant correlation between performance on real and virtual tasks

Advantage over real world testing (ease of administration, systematic stimulus control, more accurate response measurement)

Providing distractions and stressors

Conventional tests devoid of these yet those with executive disorders often said to have an inability to inhibit external distractions

In VR they can be manipulated to produce conditions which are controlled yet more like real life

In rehab distractions can be initially removed and then gradually re-ntroduced

V-STORE Virtual fruit shop Representation of user in front of conveyor

belt with baskets (1-3) crossing the room Can introduce distractions – light going

on/off, progressive dimming, ‘phone ringing, belt speed changing – to increase difficulty and time pressure

Able to look at how participants compensated

Flexibility, self-initiation and organising IN VR limitations of monitoring and

recording behaviour are removed Eg Morris et al. (2002) – virtual bungalow

used to assess prospective memory, strategy formation and rule breaking in 35 patients following pre-frontal surgery with 35 IQ-matched controls

Task to help owner of 4 room bungalow move to a larger 8 room house – collect items in specified order, remember to put ‘fragile’ notices on specified items

Morris et al. (2002)

Both able to do the task but patients used less efficient strategies, exhibited more rule breaks and more prospective memory deficits

Introducing a social dimension

Avatars Even basic avatars with limit

repertoire of behaviour found to be a promising way on including a social dimension to assessment (Pertaub et al. 2002, Blascovich et al. 2002)

Ecological Validity

VR ensures test materials of consistent quality, reduces errors and inconsistencies of administration by the clinician and avoids unwanted/uncontrolled changes in the environment

Zalla et al. 2001 VR apartment consisting of a bedroom,

bathroom, kitchen and living room. Task to verbally formulate a plan to get ready

for work in the morning and then use this in the virtual apartment

7 patients with prefrontal damage and 16 controls

Patients showed more action slips, omissions and failure to initiate

Controls took longer to execute plan than to make it, patients spent similar amount of time on planning and executing

Compliance and Motivation VR allows tasks to resemble video games

and this may be more motivating , particularly for young tbi patients.

Elkind et al. 2001 developed a version of the WCST which involved a virtual beach and delivering frisbees, sodas, popsicles and beach balls to bather under umbrellas depicting these items

Compared to computer version of WCST found VR to be more difficult, interesting and enjoyable

Conclusions Work is only at preliminary stages of

development The theoretical advantages of VR in

neuropsychological assessment have been shown to be advantageous in practice but only in small scale pilot studies

No VR instruments have yet been developed Costs/skills involved in their development

hinder their development The potential is there but needs to be realised

Smart technology Technology that includes a level of

intelligence Able to provide autonomatic

assistance rather than simply detecting problems and calling for help

1.Behaviour monitoring sensors, 2. assistive support technology, and 3. a communication link between the two

Sensors Support devices

Outside assistance

Sensors

Readily available Can detect: Movement, smoke, CO, toilet use,

fridge use, bar codes, epileptic seizures

Support devices

automatic cooker shut-off valves bath tap shut-off devices that don’t

take control away from the user means for providing prompts and

reminders eg detect movement near an external door and, knowing it is an inappropriate time to go

out, to prompt them with a message to that effect.

An example A client was often restless and would often wander out

of his room at night. A wander reminder detected movement near a door

during the night, and replayed a message to discourage the client from going out.

He would still go looking for staff in the night. Discussions with him indicated that his sleeping was

severely affected by night-time anxieties. He reported that he would often wake up with some

deep concern that he wished to talk about, and couldn’t get back to sleep. He said that he knew his memory was poor, and that if he had waited until the morning he would have forgotten all about the issue that was bothering him.

Consequently he would go and try to find a staff member to relay his anxious thoughts.

Given this understanding, a piece of technology, a voice recorder was developed that would enable him to record his concerns during the night rather than go and search for a staff member. He could then replay it to the staff in the morning.

He seemed quite happy with this proposal as it meant that the issue would still be dealt with in the morning even thought he knew he would have forgotten about it.

A design was constructed that just used one large “record” button on the top. He found this very easy to operate, as he just had to reach over to his bedside cabinet, press the button, and say what was bothering him. Several messages could be recorded.

Unfortunately the messages that he recorded were not very coherent, and it was difficult for care staff to understand what was bothering him.

Although he couldn’t remember what the issue was by the morning he did realise staff were not clear and this reduced his satisfaction.

Illustrates both the potential of simple technological interventions once a clear understanding of the problem is known, and also of the need for close and careful involvement of the user in any design solutions.