AAC adults acquired neurological conditions (summary)


This article is about people who have grown up with typical speech and language skills. They have lost those skills for a number of reasons, as detailed below. 

Why was the review carried out?

It aimed to provide an update on the use of AAC technologies associated with a range of acquired medical conditions that impact on speech and communication. This review was based on USA statistics, research studies and service provisions, although it refers to studies completed in other parts of the world.

What did they look at?

They looked at the typical use of AAC systems in people with medical diagnoses of: ALS (a form of motor neuron disease, a condition that gets worse over time); TBI (a range of brain traumas); Brain Stem Trauma (an aspect of the brain that is involved in control of reflexive (e.g. breathing) and voluntary movement). This may be called ‘Locked-in-Syndrome’ in many individuals. This often means that people are anarthric – cannot say anything, rather than dysarthric – produce slurred and distorted speech; and Dementia (a progressive loss of thinking and language skills). They also looked at speech and language diagnoses: Aphasia (a speech and language difficulty usually following a stroke); and PPA (a form of aphasia that gets worse and may eventually be related to dementia).

What did they find out?

ALS: This has several characteristics that can make communication more challenging. These include: slurring of speech with eventual loss of the movement control to produce speech, breathing co-ordination difficulties and low volume of speech. They found that as things progress there is evidence that ventilation support and nutrition support can have a positive impact on quality of life experiences including both life expectancy and the length of time that AAC might be used. Research suggests a good uptake of AAC (95%) when recommended; and in those who rejected it there were often additional difficulties, e.g. dementia. One study suggests that 100% of those with ALS used AAC to within weeks or days of their death. It is reported that AAC supports offered to the individual with ALS and their family members gave a greater sense of social closeness and understanding.

TBI: The communication impact of TBI is many and varied. Those introduced to AAC early found it helpful but equally as many held out for the return of natural and effective speech. Changes in medical interventions are resulting in changes to the residual difficulties encountered, e.g. cognitive changes, memory changes, speech and communication changes. Currently there is limited information available on the usefulness of AAC in survivors of TBI.

Brain stem trauma:  Many individuals rely on AAC from an early stage due to chronic and on-going speech production limitations. Reports on AAC needs go back over two decades and suggests that there is a reliance on access to AAC systems that require minimal motor movement control.

Dementia: this is anticipated to be a growing population in the UK (as well as the USA, i.e. the focus of this article). It will impact on communication, socialisation and independent living capacity. 

Aphasia: This is evident in an approximate 1:3 part of the population from 65 years onward; irrespective of male or female ratios. This results in changes in the ability to understand and express communication. It affects thinking, language accessing skills and the ability to put words and sentences together. Individuals with severe aphasia do not tend to regain communication function that allows them to get by without AAC compensatory strategies that effectively support them to get their message across.

PPA: Once diagnosed (usually after 60 years), planning ahead is critical as the reduction in communication capacity must be expected. Individuals show signs of communication disturbance in the absence of wider cognitive disturbance over a two year period. Eventually cognitive issues are recognised, e.g. memory loss, social and emotional contentment.

What are the implications for assessment?

ALS: the timing of referral for AAC assessment is critical in terms of predicting the point at which speech is becoming too difficult and individuals are in a position to understand the usefulness of an AAC system. One recommendation is to look for changes in speech (production and clarity) rate. When someone’s speech rate drops to between 100-125 words per minute, this is an optimal time for referral.

TBI: In a recent review, 68% of people assessed were recommended AAC techniques and technology; of these 94% accepted the recommendations with 81% still making good use of AAC techniques three years later. Of those who relied on high tech options 87% used letter by letter systems, whilst 13% used symbolised communication systems (usually because they had their brain injury prior to learning literacy). Low technology options were offered to 32% of this sub group, of that there was 100% acceptance of the system to support communication and conversation.

Brain stem trauma: It is important to maintain openness to considering a range of accessing options and a more limited output (communication system) options to meet the range of needs observed in people with this particular challenge. It seems a range of communication options work for a range of people with the same medical diagnosis.

Dementia: nothing provided within this review that informs assessment processes.

Aphasia: a traditional explanation of aphasia assessment and how that relates to AAC is not available in this article.

PPA: nothing was provided within this article to inform assessment.

What are the implications for intervention?

ALS: people who supported communication (mentors, family members) found it easier to succeed if given 1-1 training support from services and contact with commercial suppliers, especially if they did not have a technical background or interest.

TBI: The statistics quoted in the assessment section (above) suggest a relevance of a range of AAC technologies. Those who gave up on their AAC system fell into one of two main groups: (i) they had recovered sufficient natural speech and language, (ii) they had lost their mentor-communication volunteer to support their (and their families’) use of the system.

Brain stem trauma: there is limited evidence to support services and therapy options in this group. There is need for extensive research in this area.

Dementia: this is best described in terms of low tech communication, i.e.  a chart or book supports communication. Concrete examples of communication situations are most helpful. A range of context specific examples are provided.

Aphasia: There is limited research information available. Those familiar with aphasia are more supportive of AAC techniques; whilst family members are keen to regain the natural speech and language abilities of the individual prior to their stroke. The capacity to regain skills is poorly documented, as is the usefulness of AAC systems. Low-tech solutions (books, communication charts) appear to have had greater success but there remains a concern about the capacity of such systems to provide real and current conversational information. There are a number of technological applications being developed to support re-gaining language and communication skills in aphasia. These need further documentation and publication. Visual scene display, a research product development, seems worthy of more extensive consideration as it provides a context for communication success, e.g. a birthday party visual scene display.

PPA: AAC interventions are limited. The article suggests the consideration of low tech materials including: remnant boards that aid reminiscence and recognition, symbols boards, photo graphic communication books. Currently there is limited understanding of how they may support people with PPA.

What are the implications for further research and development?

ALS: Access options – whilst there have been great developments in access options over the last decade; there is an on-going need to develop methods that are more robust in terms of calibration according to postural change and lighting conditions. Speech synthesis – given the age range of people with ALS using AAC, there is a need to investigate the intelligibility of current speech synthesis in a range of real life contexts, e.g. how intelligible synthetic speech is to elderly people in long term care settings. Access to other technologies – this varied and currently seems age related but there is a suggestion that looking at the access to social media as a way of maintaining social contact whilst using AAC is not well understood. Mentor instruction – this is often related to who is available rather than based on technological confidence. It is suggested that regular training support is needed but that there is limited understanding of how this works in a real life context.

TBI: Many letter-by-letter systems offer an encoding system that enables the storing of phrases and sentences under a letter sequence. This prediction method lacks detailed research and many people who accessed and used this system suggested that they rarely sued it as it was ‘just too difficult. This suggests an on-going need to understand what supports encoding language generation method. Secondarily, people with TBI often aim to transition to semi-independent living circumstances. It seems there is limited understanding of the impact of a key ‘communication buddy’ during these phases of transition.

Brain stem trauma: there is need to explore motor learning theory (repetitive learning) in this group to see if people can re-learn motor sequencing routes that enable access to and use of AAC systems. Eye tracking research remains poorly understood. More work is needed in terms of: (i) proper lighting of the system to aid communication, (ii) precise positioning of the technology to support access, (iii) limited residual head movements (which support access to the communication system), (iv) the capacity to individualise the calibration of the system that can cope with changing g calibration needs of the user, i,e. changing muscle tone for example.

Dementia: there are studies underway exploring the integration of reminiscence and linguistic capacity skills. These have yet to be shared across research stakeholders.

Aphasia: there is much to be understood including: the relevance of commercial computer software, digital photography and Internet tools and how these relate to personalised and contextualised low-technology solutions. Natural sounding speech technologies were a concern that relates to previously expressed issues within other clinical groups in this paper. Equally, we have limited knowledge of how and in what way mentors can support communication in the person with aphasia and specifically how that relates to AAC. Lastly, understanding the perspectives of non-AAC specialists’ perspectives on what can be achieved needs further explorations, including GPs, specialist rehab teams, e.g. the consultant geriatrician.

PPA: the type, effectiveness and timing of AAC interventions are non existence in the literature, as well as facilitator support evaluations. We probably need N=1 case study reports over a period of years to inform the evidence base.


Further things you may want to look at:

complex communication needs (CCN)

brain stem trauma


Added to site December 2012