Predicting Language Outcome and Recovery After Stroke (PLORAS)


Frequently Asked Questions


Questions about taking part:

Stroke and symptoms

Are you including any kind of stroke in your research?

We are including ischemic strokes (clot) and haemmorhagic strokes (bleed).

We are not including:

  • Brainstem stroke (only).
  • Subdural haematoma.
  • Subarrachnoid haemorrhage.
  • Transient Ischemic Attack (TIA).
  • Lacunar strokes
  • People whose symptoms lasted fewer than seven days.
  • People who also have another neurological diagnosis - for example, dementia, Multiple SclerosisParkinson's disease, traumatic brain injury or hypoxic brain injury.
My stroke symptoms lasted less than one week - can you still include me?

No.  We are only including people whose symptoms lasted more than one week.

I had aphasia but am now recovered - are you interested in including me?

Yes!  We are very interested in people who have recovered from aphasia.

We may ask if you are happy to have a functional MRI scan.  
This involves doing tasks such as reading and talking in the scanner.  
This can help us to learn how the brain may have recovered.

I never had aphasia after my stroke - are you interested in including me?

Yes.  We are looking for anyone who has had a stroke (except brainstem stroke or subarrachnoid haemorrhage).  

It does not matter if you never had aphasia.

Can you tell me when I will recover and how I can improve?

No.  Although we hope to do this in the long term, we cannot do this at this stage

This is not a clinical appointment, so we cannot make any diagnoses or recommendations for treatment.


Will I get a choice of appointment dates?

Yes.  We can be very flexible with appointment dates.  

People who do not live in London sometimes arrange the date around when they may be visiting friends or family in London or going to another event.

Will I need to come and see you more than once?

Most people only need to come and see us once.

We invite some participants back for further testing.
This includes inviting people who have a lot of language problems to come back to see how they may be changing over time

Can I volunteer in a few months as I'm not up to the trip at the moment?

Of course.  You might like to apply now and we can start the process of checking you are safe to have the scan.  

Then you can let us know when you feel able to visit us.

MRI scan

I had an MRI scan in hospital - why do you need to check that I am safe to have an MRI scan with you?

Our guidelines are different because we are a research centre not a hospital.

This means that some metal implants may be considered fine for a hospital scanner, but have not yet been investigated or approved for scanning in research centres.

I have been declined because I have metal in me - does this mean it is not safe for me to have an MRI scan in hospital?

Hospitals have different guidelines to us.  

If we have declined you this does not necessarily mean that you cannot have an MRI scan in hospital.

How long will it take for you to check that I am safe to have an MRI scan with you?

This varies from person to person, but it can take several weeks or months.

Generally, if you have had a lot of surgery it is likely to take longer.  

It is helpful if you can give us as much information about procedures as you can, including dateshospitals and consultant names.

Do not worry if you do not hear from us for some time.

You can Contact Us at any time to check on progress!

I had surgery many years ago and do not know where it was performed or by whom - is this a problem?

We will contact your Medical Records department to see if they have any notes on the procedure.

If we cannot get hold of any records (sometimes they have been destroyed) we may ask people if they are happy to have an X-ray to see if there were any metal implants used in the procedure.

I use a wheelchair and need assistance to transfer - will I be able to go in your scanner?

We have an 'MRI Safe' wheelchair which you will use in the scanner room.

Please bring someone with you who is able to help you transfer.

We do not have a hoist for transfer to the MRI scanner.

I have had lots of MRI scans - is it OK to have another one?

Yes,  there are no known risks of having multiple MRI scans.

I don't want to have an MRI scan but I would like to take part - is this possible?

At some stage we hope to be able to use CT or MRI scans carried out at local hospitals

Please tell us that you are interested but would like to wait until we can use your hospital scan.

Language assessment

I get tired very easily - what will happen if I cannot finish all the tasks?

This is not a problem.  

We offer as many breaks as you need through the day.  
If we do not finish all the tasks, we can visit you at home to finish the language assessment.

Travel and Expenses

I cannot travel alone - can you pay for my relative/friend/carer to accompany me?

Of course.  We can pay for travel expenses for one person to accompany you.

I live a long way from London - will you be able to pay for my travel expenses?

Many people visit us from outside London.

We pay travel expenses up to a maximum of approximately £100.  
It helps if you book your tickets in advance as this is often cheaper.

Sometimes we arrange for several people from one area or stroke group to visit us and we can arrange a minibus.  

Do you pay for meal expenses?

No.  Unfortunately we cannot pay for meal expenses.

You can bring a packed lunch and eat it in our conservatory, or in the park outside if the weather is nice!

There are several coffee shops and restaurants nearby

Do you pay for overnight accommodation expenses?

No.  Unfortunately we cannot pay for overnight accommodation expenses.

People who visit us from outside London often time their visit for when they are planning to stay with family or friends in London.

Will I get any compensation for my time?

Yes.  We will give you £10 for each hour you spend at the research centre.


I cannot volunteer with you (various reasons) but I would like to be updated on the research - how can I do this?
Does the study have ethical approval?

Yes.  The study has been approved by the London Queen Square Research Ethics Committee.

What if I change my mind about taking part on the day?

There is no obligation to have a scan or language assessment if you change your mind on the day.

You can still receive updates via our Newsletter if you wish.

General questions about the study:

Stroke type

Is there any evidence that haemorrhage vs. infarct is more likely to cause aphasia?

Infarcts are much more consistent in the areas they affect as they stick to cerebro-vascular territories.  The area of damage is much more variable with a haemorrhage.

Whether the patient has an infarct or a haemorrhage, the size and location of lesion remain the key factors in aphasia presence and recovery.

Do we have any statistics on the occurrence of right hemisphere language dominant patients?

Up to 5% of people are right hemisphere dominant.
10-15% are bilateral. 

The occurrence of atypical language dominance is higher for left-handed and ambidextrous people than for right-handed people.
The majority of people are typically left hemisphere dominant.

Does type of stroke (haemorrhage vs infarct) make a difference to recovery?

We collect data on type of stroke but what we are finding is that it is lesion site that enables us to make predictions for some patients, regardless of whether the stroke was caused by an infarct or haemorrhage.

Structural MRI scanning

Can you see critical lesions sites on a clinical scan?


Not by eye.  The image needs to be put in a reference space (a standard template which makes all brains a consistent size and shape, and makes comparisons possible) and through analysis software to be able to identify the extent and exact location of the lesion.  Other lesions in other regions also need to be checked for, as damage elsewhere may be having an impact.

How does the finding about the importance of the superior longitudinal fasciculus (one of the critical lesion sites) fit in with important language regions found by other studies?


The superior longitudinal fasciculus incorporates the arcuate fasciculus, which has been known to be important in language (e.g. repetition) for some time.

We are always looking at the lesion in three dimensions (not all other studies have).

What is new or different about our finding is the consistency across patients, the effect of time post stroke, and the implications for prediction.

Will PLORAS ever be able to use clinical scans which are less than 3 months post stroke?

In time this is certainly the plan.  We are working on this as a project within the project, with the aim of to analysing the system on a range of scans.

It might be necessary to develop special techniques to analyse clinical/earlier scans in the way that is required.

Could you see differences pre- and post-therapy on a research or clinical scan? What kind of change and after how much time would change be detectable?

Not by eye.  You might see an increase in the structure of some regions around the lesion.

There is lots of evidence that when you learn, the structure of the area used for that learning/task develops.  The reasons are not certain, but could be due to vascular changes associated with increased blood supply. 

There would need to be lots of comparisons to be confident that structural changes were due to therapy, i.e. it is not just a case of doing single pre- and post-scans.

It is interesting to note that lesions do change over time, but get bigger rather than smaller.

Functional MRI scanning

Is it possible that 'inappropriate' brain areas would be activated in patients with aphasia during language tasks - as a result of increased effort?

Yes.  There is evidence that in the early stages of recovery the right hemisphere is more active, but this decreases as the patient recovers.  There is a 'struggle component', i.e. lots of the brain will be activated when someone is trying hard to do something difficult.

Any use of the language system involves 'cognitive control processes', so you are not going to get activation just in a limited 'language' area.

It is difficult to say that any area is 'inappropriate' or 'redundant', as we do not know for sure that this area is not helping.

Has the fMRI we've done so far picked up right hemisphere activation during language tasks?

Yes, but right hemisphere activation also contributes to language tasks in healthy controls; and right hemisphere activation in patients is often within the normal range.

This is similar to what we would find if patients started to write with their left hand following impairment to their right hand.   Their use of the left hand would be unusual for them but not atypical, given that left handed people use their left hand.

Methods and analysis

How do we account for the effect of therapy and isn't that really important?

We do expect therapy to be contributing to recovery.  At present, the effect of therapy may be accounting for some of the variance we are seeing in recovery rates within patients with similar lesions. 

However, there are some lesions where the effects of lesion site are very consistent, irrespective of the type or duration of therapy.

What do you mean by 'recovery' from aphasia?

By recovery, we are simply referring to improvements over time which we measure using a standardised language assessment (Comprehensive Aphasia Test). 

This does not mean that the patient will necessarily be back to how they were functionally before the stroke. 

The concept of recovery includes many dimensions: PLORAS looks purely at impairment level, i.e. the scores on the Comprehensive Aphasia Test. 

All we can estimate is how far we expect their performance to be from the normal (non-aphasic) range. 

Surely recovery depends on so many factors, such as age and motivation?

Indeed, age and motivation will be contributing factors.  At present, these and other factors will be accounting for some of the variance we are seeing within patients with similar lesions. 

However, there are some lesions where the effects of lesion site are very consistent, irrespective of age, motivation and many other factors that often thought to play important roles.

Doesn't the fact that different people have had different therapy mean that we can't compare recovery accurately?

Many factors are likely to contribute to recovery of a patient's communication skills, including speech and language therapy. 

At present, the effect of therapy is likely to be accounting for some of the variance in recovery rate that we are seeing within patients with similar lesions, and this is something we aim to examine to further. 

However, there are some lesions where the effects of lesion site are very consistent, irrespective of the type or duration of therapy.

How strong a relationship are we finding between lesion, behaviour and time post stroke?

Our results have shown a surprisingly strong influence of time post stroke that is maintained over decades.  

This is being investigated by longitudinal studies of patients, and with attempts to replicate the effects in new samples of patients.

Do we need lesion data to predict recovery or could we just base this on assessments, e.g. early scores on the Comprehensive Aphasia Test?

Our argument is that lesion data will improve the predictions.  It is true to say that recovery will be faster and more complete in those who are not too severely impaired in the early weeks after their stroke.   

However,  there are always exceptions.  For example, some patients can make fast and full recoveries despite very severe aphasia in the early days.   

Lesion information helps to predict which patients are likely to recover faster than others.

How long do you leave between re-tests on the Comprehensive Aphasia Test?

This depends on the individual patients.  If recovery happens fast, then we would test more often, perhaps repeating tests after 3 months.  If recovery occurs more slowly, then re-testing might be every one to two years.

Is it possible that participants do better on re-tests as a result of familiarity or learning?

This is unlikely as we do not give feedback on errors or correct answers. 

Clinical application 

Where does verbal dyspraxia fit into the picture? i.e. how do we separate what is aphasia and what is dyspraxia? And how does this affect recovery?

This is a difficult area as it is difficult to separate phonological/dyspraxic errors in the limited context of the Comprehensive Aphasia Test.

Our predictions are currently general in terms of speech production - we will be refining them later.

What will the findings mean for therapy and its efficacy?

Our prediction is that the effect of therapy is going to depend partly on the patients' presenting symptoms and partly on the site of the lesion.  

Accounting for lesion site may improve our understanding of why therapy can have different effects in different individuals with the same presenting symptoms.

Can you give my patient a prediction about their recovery now?

No.  Our aim is to do this for future aphasic stroke patients. 

We are still collecting and analysing data in order to improve the range and accuracy of our predictions.

Will all aphasic stroke patients be able to be given a prediction?

Predictions for some lesions are strong; others less so.

Each comes with a confidence rating and we are working on improving less strong predictions.

We will only ever be able to tell patients the 'most likely outcome' - the confidence level will never be 100%.

We hope that in the future our prediction data will be available for health professionals in clinical settings around the UK.

Do you think that in the future your findings might be interpreted as 'no chance of recovery, no need to bother with therapy'?

Our hope is that our findings will inform therapy, so the best and most appropriate therapy is chosen for each patient.

For example, we are learning more about how preserved brain tissue can support recovery and this could inform the choice of therapy task.

Even for our patients who have had very devastating stokes that have hit the areas we know are really important for language, our research has found that there is still potential for recovery.  For patients with such strokes (i.e extensive damage to the critical lesion sites) we might expect recovery to be much slower or for language comprehension to improve even if speech is still very problematic.

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