Newcastle University

Project:

Range and pattern of change over time in objective and perceived measures of speech, voice and swallowing in Parkinson's disease

From May 2006 to August 2006
Project Leader(s): Dr Nick Miller
Staff: E Noble, A Jones, D Burn
Contact: Dr Nick Miller
Partners: Parkinsons Disease Society

We followed up 31 individuals with Parkinson’s with whom we had conducted speech, voice and swallowing assessments approx. 3 years previously, to examine the extent and pattern of possible changes over time and how changes in different areas (e.g. limb control, tongue, lips, breathing) might relate to each other. We are the first to investigate possible changes from the point of view of basic motor performance (ie how fast/far/fluently the tongue, lips and vocal cords move), and combine this with clinical measures of how intelligible the speaker is to strangers, how natural/ disordered their voice sounds and how they perceive themself as a communicator. We assessed swallowing efficiency (millilitres of water drunk per second) and participants rated their impression of how they coped with swallowing different kinds of food and drink and their experience of mealtimes.
Against a background of significant decline in movement (measured by standard clinical measures looking at walking, balance, tremor and so forth) speech and voice also changed. However, changes were not necessarily in direct proportion to limb movement changes; not all speech and voice changes appeared to progress at the same rate when we looked at results for the group as a whole. For instance, the acoustic measure of stability of movement of the vocal cords (related to changes in stiffness and control of the muscles in the voice box which influences in turn how rough or tremulous ones voice sounds) did not deteriorate significantly; sustainability of vocal cord movement and breath support for producing voice did. Rapid movements of the back of the tongue (to say sounds k, g) fell from baseline. Lip movement (for saying p, b, m etc) also declined but not so markedly.
Changes impacted on conversations. People were less intelligible; strangers felt their speech sounded more disordered. In terms of how this affected the feelings of the individual in relation to communication the group as a whole felt significantly less adequate, less confident and more worthless. Degree of patience, talkativeness and frustration had not altered so much – but then these had already been prominently affected when assessed three years ago. Swallowing was a little slower for the group overall and some foodstuffs more difficult to manage.
These are group results. Striking was the degree of individual variability. Some people barely changed over the 3 years, others showed dramatic decline.
Our findings are important as the first indepth study of changes in communication. They deliver important information about the degree and pattern of change against which to judge the success of interventions to support people with communication difficulties. They deliver vital insights for possible candidate target behaviours for therapy to bring about improvement or maintain level of functioning. They offer key information on the feelings and impact of changes on individuals.