Roles of cognitive status and intelligibility in everyday communication in
people with Parkinson’s disease: A systematic review
Maxwell S Barnish,a,b Daniel Whibley,b Simon MC Horton,a Zoe R Butterfint,a
Katherine HO Deanea
a = School of Health Sciences, University of East Anglia, Norwich, UK
b = Epidemiology Group, Institute of Applied Health Sciences, University of
Aberdeen, Aberdeen, UK
Running title: Everyday communication in PD
Correspondence to: Dr Maxwell S Barnish, Epidemiology Group, Polwarth Building,
Foresterhill Campus, University of Aberdeen, Aberdeen, UK, AB25 2ZD;
[email protected]; (+44) 01224 437217
1
Abstract
Background: Communication is fundamental to human interaction and the
development and maintenance of human relationships and is frequently affected in
Parkinson’s disease (PD). However, research and clinical practice have both tended
to focus on impairment rather than participation aspects of communicative deficit in
PD. In contrast, people with PD have reported that it is these participation aspects of
communication that are of greatest concern to them rather than physical speech
impairment.
Objective: To systematically review the existing body of evidence regarding the
association between cognitive status and/or intelligibility and everyday
communication in PD.
Methods: Five online databases were systematically searched in May 2015 (Medline
Ovid, EMBASE, AMED, PsycINFO and CINAHL) and supplementary searches were
also conducted. Two reviewers independently evaluated retrieved records for
inclusion and then performed data extraction and quality assessment using
standardised forms. Articles were eligible for inclusion if they were English-language
original peer-reviewed research articles, book chapters or doctoral theses
investigating the associations between at least one of cognitive status and level of
intelligibility impairment and an everyday communication outcome in human
participants with PD.
Results: 4816 unique records were identified through database searches with 16
additional records identified through supplementary searches. 41 articles were
suitable for full-text screening and 15 articles (12 studies) met the eligibility criteria.
10 studies assessed the role of cognitive status and 9 found that participants with
2
greater cognitive impairment had greater everyday communication difficulties. 4
studies assessed the role of intelligibility and all found that participants with greater
intelligibility impairment had greater everyday communication difficulties, although
effects were often weak and not consistent.
Conclusions: Both cognitive status and intelligibility may be associated with
everyday communicative outcomes in PD. The contribution of intelligibility to
everyday communication appears to be of small magnitude, suggesting that other
factors beyond predominantly motor-driven impairment-level changes in intelligibility
may play an important role in everyday communication difficulties in PD.
Keywords: Parkinson Disease; Cognition Disorders; Speech Disorders;
Communication; Social Participation; International Classification of Functioning,
Disability and Health; Review, Systematic
3
Introduction
Parkinson’s disease (PD) is a common neurodegenerative condition that affects
around 1.5% of people over 65 in Europe [1] with considerable worldwide variation in
prevalence [2]. In light of the impact of PD on quality of life [3] and the global ageing
population [4], PD should be considered a major healthcare challenge of the future.
PD was originally characterised largely in terms of its motor features [5], which still
form the basis of recognised diagnostic criteria [6-8]. However, research has
revealed a wide range of non-motor symptoms [9] including cognitive impairment
[10] in over a quarter of patients.
Communication is fundamental to human interaction [11] and the development and
maintenance of human relationships, including those developed in a healthcare
context. Around 70% of people with PD report dissatisfaction with their everyday
communication [12]. The International Classification of Functioning (ICF) [13]
provides a useful framework for conceptualising the distinction between ‘speech’
difficulties at the impairment level and ‘communication’ difficulties at the activity and
especially the participation level. Indeed, the extent of communicative difficulty at the
ICF participation level may not be closely associated with severity of speech
impairment at the ICF impairment level, such as intelligibility [12,14]. Other factors
beyond speech impairment, such as cognitive status [15], may play an important role
in determining participation level outcomes, which we call ‘communicative
participation’ following Eadie et al [16].
In recent years, there has been increased focus on the benefits of service user
involvement in the development and prioritisation of research in order to avoid
mismatch of priorities [17,18]. Miller et al [19] conducted in-depth qualitative
4
interviews with people with PD in order to identify the nature of speech and
communication changes, using these terms in the technical senses defined above,
and to assess what impact these changes had on their lives. In this study, “central
concerns were not that voice was monopitch, sound contrasts difficult, or
similar…Rather individuals focused on the impact changes exerted on ability to
communicate [and] their view of themselves”. In contrast, the body of published
literature for impairment-level speech changes in PD is much greater than that about
communication and there is evidence that the ICF participation level does not form a
major focus of many speech and language therapists’ assessment and intervention
practices for PD [20]. Therefore, there appears to be a mismatch between the
priorities of people with PD and those of researchers and clinicians.
In light of this potential mismatch of priorities, it is important to conduct a systematic
and comprehensive appraisal of evidence regarding the associations between i)
speech and communication difficulties in PD and ii) cognitive status and
communication difficulties in PD. This enables evaluation of how closely related the
concepts are that form the respective priorities of people with PD and of researchers
and clinicians. As no summary appraisal of available evidence was identified by a
search of the literature, we decided to conduct a systematic review to address these
research questions and report the findings in this article.
Materials and Methods
We undertook a systematic review of studies investigating the associations between
cognitive status and/or intelligibility and everyday communication in PD. PRISMA
guidelines [21] were followed. Due to the heterogeneity of study designs and
measures, a narrative systematic review rather than a quantitative meta-analysis
5
was conducted. This study was a systematic review of existing literature and no
human or animal participants were recruited. Therefore, no ethical approval was
required.
Explicitly stated, our research questions were:
1) To assess associations between cognitive status and communication
outcomes in PD
a) How many studies have assessed the relationship between cognitive
status and communication outcomes in PD, taking the definition of
communication outlined earlier?
b) Of the included studies, what proportion identified a statistically significant
association between at least one measure of cognitive status and a
communication outcome measure in PD?
c) Taking into account all relevant data presented in the included studies, is
the evidence in favour, inconclusive or against with regard to the existence
of an association between cognitive status and communication in PD and
what does it say about the strength of this association?
d) Do the cognitive measures used in the included studies provide insight into
which aspects of cognitive status might be most predictive of degree of
communicative difficulty in PD?
2) To assess associations between intelligibility and communication outcome in
PD:
a) How many studies have assessed the relationship between intelligibility
and communication outcomes in PD, taking the definition of
communication outlined earlier?
6
b) Of the included studies, what proportion identified a statistically significant
association between at least one measure of intelligibility and a
communication outcome measure in PD?
c) Taking into account all relevant data presented in the included studies, is
the evidence in favour, inconclusive or against with regard to the existence
of an association between intelligibility and communication in PD and what
does it say about the strength of this association?
Search methods
Five online databases were systematically searched in May 2015: Medline Ovid
(1948), EMBASE (1980), AMED (1985), PsycINFO (1806) and CINAHL (1982). The
search strategy was designed by MSB and KHOD and formed 3 blocks: ‘Parkinson’s
disease’, ‘cognitive status or intelligibility’ and ‘everyday communication’. Key terms
were mapped to database-specific subject headings (MeSH) where available and
exploded to include sub-categories. Items within the blocks were linked with an ‘OR’
Boolean operator and blocks were linked with ‘AND’. The full Medline search
strategy is provided in the supplementary data accompanying this article.
Supplementary searches were conducted by screening bibliographies of extracted
articles and an online search engine (Google Scholar).
Eligibility criteria
For inclusion in the review, articles had to meet the following eligibility criteria:
(1) Full-text original peer-reviewed research article, book chapter or doctoral
thesis
(2) English language publication
(3) Empirical investigation
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(4) Human participants with PD, results being presented separately from other
conditions
(5) Explicit assessment of cognitive status or level of intelligibility impairment
(6) Linkage thereof to oral everyday communication outcomes including
communication-focused pragmatics
(7) Results separable from any investigation of therapy, medicine or surgery
Titles and abstracts were independently assessed for potential inclusion by two
reviewers (MSB and DW) and any disagreements resolved by discussion. Full texts
were obtained where abstracts met eligibility criteria and were independently
assessed by MSB and DW. Those meeting the eligibility criteria were included in the
narrative synthesis.
Data extraction
Data were extracted independently for each included study by MSB and DW. Data
were entered onto standardised forms capturing study characteristics and study
measures and results respectively (see supplementary data accompanying this
article), subsequently synthesised into a summary of findings table (Table 1). Where
appropriate, articles were grouped into studies.
Quality assessment
Quality assessment was conducted using the Threats to Validity tool [22], which
KHOD previously helped to develop. It was configured for the purposes of our review
by MSB and KHOD. Quality was assessed independently by MSB and DW for each
included study, enabling generation of a ‘Threats to Validity Table’ (Table 2) profiling
the methodological performance of each study. Following Daley et al [22], studies
were assessed as at overall low risk of bias (High quality) if ≥70% of applicable
8
quality items were assessed as at low risk of bias, overall moderate risk of bias
(Moderate quality) for 40-69% and overall high risk of bias (Low quality) for ≤39%.
Results
Database searches yielded 4816 unique records. Sixteen additional records were
identified through supplementary searches. Figure 1 shows the PRISMA flow chart
depicting each stage of study identification. After reviewing abstracts, 41 were
suitable for full text retrieval. Following thorough evaluation, 15 articles [12,14-15,2334] (12 studies) met the eligibility criteria.
Summary of studies
Eight studies assessed only cognitive status as a predictor of communicative
difficulties, two studies only assessed intelligibility as a predictor and two studies
assessed both cognitive status and intelligibility as predictors. Ten studies used a
cross-sectional design, one used a cohort study design and one used a mixed
methods design. Five studies were conducted in the USA, four in the UK, two in
Canada and one in New Zealand. Two studies were assessed at low risk of bias, five
at moderate risk of bias and five at high risk of bias (Table 2). The three most
common threats to validity were a lack of participant representativeness (11 studies,
92%), concerns over task or stimulus order effects (11 studies, 92%) and a lack of
sample size rationale (10 studies, 84%). The approach to intelligibility assessment
undertaken by each study is profiled in Table 3. The findings of included studies are
summarised below and provided in full in the Appendix.
Cognitive status
Ten studies assessed the role of cognitive status and 9 found a positive result,
defined as a significant association between at least one measure of cognitive status
9
and one measure of everyday communication. Of these nine studies, one [25] was
assessed at low risk of bias, four [15,24,29,33-34] at moderate risk of bias and four
[23,28,31,32] at high risk of bias. Five [28,30,31,33,34] of these studies provided
evidence that greater impairment of cognitive status is associated with greater
impairment of conversational pragmatics. Hall et al [28] found that Mini Mental State
Examination (MMSE) [35] score was strongly associated with score on the Rating
Scale of Pragmatic Communication Skills [36]. McKinlay et al [30] found that
measures of working memory and processing speed, but not attentional set-shifting,
predicted pragmatic communication on the Test of Linguistic Competence-Extended
[37]. McNamara et al [31] found that Stroop [38] and Tower of London [39] test
parameters were associated with score on the Pragmatic Protocol [40]. Monetta et al
[33] found that verbal working memory and verbal fluency predicted aspects of the
Discourse Comprehension Test [41]. Pell et al [34] found that the ability to make
enriched social inferences on The Awareness of Social Interference Test [42] was
associated with working memory capacity and frontal lobe functioning.
Three studies [15,23,24,29] found an association between cognitive status and
narrative organisation and/or turn taking. Alpert et al [23] found that a composite
dementia score was negatively associated with frequency of internal pauses and
frequency of simultaneous speech and positively associated with mean length of
internal pauses. Ash et al [24] found that reverse digit span, letter-guided fluency,
category fluency and Stroop time were associated with communicative parameters
from the analysis of story narration. Lesser et al [15,29] found that while PD
subcortical dementia and PD with Lewy body dementia groups did not differ overall
with regard to conversation analysis parameters, people with PD and Lewy body
10
dementia had more difficulty orienting the conversation partner to a new topic and
retained fewer pre-morbid communicative situations.
One study [25] found that worse Montreal Cognitive Assessment (MoCA) [43] score
was associated with greater impairment of everyday communication as measured
the Communicative Participation Item Bank (CPIB) [44] but not the Communicative
Effectiveness Survey (CES) [14]. Sub-domain analysis was reported. MoCA
‘Naming’ sub-scale was identified as a predictor of CES score, while MoCA
‘Executive and Visuospatial’ and ‘Attention’ subscales were marginal predictors of
CPIB.
One study [12,32] had a negative result. It was assessed as high quality and
investigated the association between cognitive status and communicative
effectiveness as measured through a semantic differential questionnaire.
Intelligibility
Four studies assessed the role of intelligibility and all found a statistically significant
association between at least one measure of intelligibility and one communicative
outcome, representing a positive result by our definition. Two [12,25,32] were
assessed at low risk of bias, one [14,27] at moderate risk of bias and one [26] at high
risk of bias. Barnish [25] found that conversational sentence intelligibility was a
significant predictor of both CPIB and CES, accounting for 43% and 19% of the
variance respectively, while read sentence intelligibility did not significantly predict
these communication outcomes. Coates and Bakheit [26] found that there was a
significant difference in intelligibility scores between those who complained of
everyday communication difficulties and those who did not. Donovan et al [14,27]
found a significant association between intelligibility and CES, although it accounted
11
for only 15% of variance. Miller et al [12, 32] found that intelligibility was a weak
(r = - 0.23) but statistically significant predictor of communicative change according
to a semantic differential questionnaire at baseline but not at follow-up.
Discussion
The systematic review reported in this article is the first to address the contribution of
either cognitive status or intelligibility to everyday communication difficulties in PD.
Of the ten studies that assessed the role of cognitive status, nine found evidence of
this association and the other study [12,32] relied on MMSE, which has been
demonstrated to be insensitive to milder cognitive impairment in PD [45-46]. The
balance of evidence is in favour of an association between cognitive status and
everyday communication in PD including communicative participation,
conversational pragmatics and narrative organisation/turn-taking. With regard to the
implication of specific cognitive functions, there is preliminary evidence that
executive function might be implicated, although before any conclusions can be
drawn this requires further exploration in future studies, which may also seek to
assess neural correlates using imaging techniques. Of the four studies that assessed
the role of intelligibility, all found evidence of a significant association. However, the
strength of association differed regarding on the nature of the intelligibility
assessment and the communicative outcome measure. Overall, the contribution of
intelligibility deficits to everyday communication difficulties appeared of modest
magnitude.
The first key conclusion of this systematic review is that we found evidence to
suggest that both cognitive status and intelligibility may be associated with everyday
communicative outcomes in PD. The second key conclusion is that the contribution
12
of intelligibility to everyday communication, while statistically significant, appears to
explain a relatively small proportion of the variance in everyday communication
outcomes. This, in turn, suggests that other factors beyond predominantly motordriven impairment-level changes in intelligibility may play an important role in
everyday communication difficulties in PD.
These conclusions must, however, be viewed as preliminary since there are several
key limitations in the identified body of literature. Firstly, most included studies were
cross-sectional, which preclude definitive inference of causality [47] since they
provide no information on the time sequence of the hypothesised exposure and
outcome. Secondly, only two of the 12 studies (17%) were assessed at low risk of
bias and five (42%) were assessed at high risk of bias, suggesting that study quality
in this field of inquiry may be problematic. Thirdly, only 2 studies (17%) reported a
sample size rationale and the median number of people with PD included per study
was only 18.5, showing that most studies used small samples. Therefore, many
included studies may have limited statistical power and be limited in their
generalisability beyond the sample.
Everyday communication is fundamental to successful functioning [11], and
difficulties in this area are both common [12] and seen as a priority by people with
PD [19]. However, established paradigms in the conceptualisation and treatment of
communicative difficulties in PD have focused predominantly on impairment-level
motoric alterations in speech. For example, evidence from surveys of UK speech
and language therapists has shown that everyday communication, especially at the
participation level, does not form a major focus of many therapists’ assessment and
intervention practices for PD [20] and progressive dysarthria more generally [48].
13
This is despite clinical guidelines [49] and a belief by both clinicians [48] and people
with PD [19] that communicative participation is important.
Indeed, the number of studies eligible for inclusion in our systematic review is
relatively small. The vast majority of studies assessing speech in PD have not looked
at changes beyond the ICF impairment level. The reasons for this focus are
unknown, although they may parallel a similar situation in clinical practice [20,48].
One possible explanation is the lack until relatively recently of any self-report
measure that solely measured communicative participation [16]. CPIB offers the
prospect of addressing this shortage. CPIB was developed using item-response
theory [50] and subsequently validated in PD in the USA and New Zealand [51] as
well as the UK [25]. In light of its relatively recent development, CPIB was only used
in one study [25] included in this review. Studies varied considerably in terms of the
outcome measures used and many measures did not adequately distinguish ICF
Activity and Participation level effects. Moreover, the studies by Hall et al [28],
McKinlay et al [30], McNamara et al [31], Monetta et al [33] and Pell et al [34] used
outcome measures that focused on specific aspects of pragmatic communicative
functioning, which may not be generalizable to other aspects of everyday
communication. Issues of measurement need to be addressed in future studies.
Issues regarding how intelligibility was assessed in included studies also need to be
considered. As profiled in Table 3, the four studies that assessed intelligibility shared
some commonalities but also had some considerable differences with regard to
intelligibility assessment. All four studies conducted all or most of the recordings in
participants’ own homes. This is likely to offer a more realistic real-world recording
environment than a studio recording, but would lack the extent of background noise
encountered in certain common everyday communicative situations such as cafes
14
and community centres. Two studies [14, 26,27] did not address stimulus
organisation, while Barnish [25] used a blended presentation approach using Latin
Square [52] allocation of stimuli to assessors and a randomised presentation order to
minimise stimulus exposure effects and learning biases [53,54] and Miller et al
[12,32] randomly assigned whole recordings of speakers to assessors. Two studies
[14, 25, 27] presented stimuli in context, one study without context [12,32] and one
study [26] did both. One study [25] used a large pool of assessors without expertise
in speech disorders, one study [12,32] used a small number of assessors without
expertise in speech disorders and two studies [14, 26, 27] used a small number of
expert listeners. All four studies used transcription tasks. Intelligibility assessments
may lack comparability across studies and task-specific effects may limit
generalisability. It is possible to suggest that intelligibility assessment tasks may
overestimate the deficit when transferred to everyday communicative situations,
which in turn could in part explain the weak association between intelligibility and
everyday communication outcomes. However, this is not supported by the finding of
Barnish [25] that conversational speech intelligibility predicted communicative
outcomes, while read speech intelligibility did not.
If confirmed in further, more rigorous studies, the findings presented in our
systematic review that intelligibility does not appear particularly strongly associated
with the degree of everyday communication difficulties in PD, and that other factors
such as cognitive status may play an important role, would present a challenge to
prevailing assessment and treatment practices. Further research is required to
confirm these findings. It is recommended that future studies i) are designed in
accordance with rigorous quality assessment tools, ii) have sufficient sample size to
address issues of statistical power and generalisability and iii) use prospective cohort
15
designs to offer greater insight into temporal relations. Moreover, the investigation of
communicative outcomes could be embedded into large cohort studies of the
general natural history of PD to provide access to larger, more representative
samples. In addition, if research in this field could agree upon a standard set of
cognitive, intelligibility and communicative measures, this could facilitate metaanalysis.
This systematic review has a number of key strengths. Firstly, it is the first
systematic evaluation of the extant body of evidence relating intelligibility and
cognitive status to everyday communication in PD. Secondly, searches covered five
key bibliographic databases with supplementary searches to minimise risk of
selection bias. Thirdly, rigorous standardised screening and data extraction
techniques were used. Fourthly, quality assessment was conducted with a tool that
was specifically designed for use in assessing observational studies. Fifthly, review
procedures were conducted independently by two reviewers as a quality assurance
measure. There are, however, a couple of limitations that should be considered.
Firstly, only articles published in English were considered. However, English is the
primary international language of scientific communication and there is evidence that
potential language bias does not significantly affect the result of systematic reviews
[55]. Secondly, the heterogeneity of study methods, including both exposure and
outcome measurement, precluded the use of meta-analysis, which could have
provided a pooled estimate of effect size.
Acknowledgements including sources of support
We acknowledge funding from a University of East Anglia (UEA) PhD studentship to
MSB, during whose PhD at UEA the idea for this systematic review was conceived
16
and an early version conducted. The idea for this systematic review was conceived
by MSB (Chief Investigator), KHOD, SMCH and ZRB. Project management was
conducted by MSB. Searches were designed by MSB and KHOD and then executed
by MSB. Screening, data extraction and quality assessment were conducted by MSB
and DW with advice from KHOD. All authors contributed to the interpretation of the
findings. MSB wrote the first draft of the manuscript and all authors contributed to
revisions and approved the submission.
Conflicts of Interest
The authors have no conflict of interest to report.
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23
Tables
Table 1. Summary of systematic review findings
Factor
N studies
Total sample
size
10
291
Results
summary
Cognitive status
P=9
N=1
Intelligibility
P=4
4
222
N=0
Quality
summary
H=1
M=4
L=4
H=1
M=0
L=0
H=2
M=1
L=1
H=0
M=0
L=0
P = positive study – defined as providing evidence of at least one significant association between the relevant predictors and
outcomes, N = negative study, H = high quality, M = moderate quality, L = low quality – calculation details given in methods
section
24
Table 2. Threats to Validity table profiling risk of bias in included studies
Threats to validity
Alpert Ash Barnish Coates Donovan Hall Lesser McKinlay McNamara




Selection bias
?
?
?
?
?
(Diagnostic accuracy)



Selection bias
?
?
?
?
?
?
(Participant
representativeness)





Selection bias
NA
NA
NA
?
(Group equivalence)


Chance
?
?
?
?
?
?
?
(Sample size rationale)
 







Detection bias
(Task validity)
Detection bias
?
?
?
?
?
?
?
?
?
(Order effects)





Detection/Reporting
?
?
?
?
bias (Appropriate
analysis)








Reporting bias
?
(Conflict of interest)
Quality
29
50
71
14
63
38
50
38
38
%✓
summary Classification
L
M
H
L
M
L
M
L
L
Miller

Monetta

Pell
?

?
?
NA


?
?
?




?
?






86
H
63
M
50
M
✓ = high quality (low risk of bias), = low quality (high risk of bias), ? = unclear, NA = not applicable to study design. H = overall high quality, M = overall moderate quality, L = overall low quality –
calculation details given in methods
25
Table 3. Profiling of intelligibility assessment
First author
Recording
environment
Stimulus
organisation
Barnish
Recorded in
participants’
homes
Coates
Recorded in
participants’
homes
Recorded in
participants’
homes (71/75)
or in clinic
(4/75)
Recorded in
participants’
homes
A blended
presentation
approach was
used. The
allocation of
stimuli to
assessors
followed Latin
Square and
presentation
order was
randomised
Not stated
Donovan
Miller
Not stated
Each assessor
was randomly
assigned the
recordings of 5
different
speakers
Intelligibility Number of
in context
assessors
or without
context?
In context
64
Assessor
expertise
Assessment
task
Staff or
students of the
University of
East Anglia
without
expertise in
speech
disorders
Transcription
In context
and without
context
In context
8
Speech and
language
therapists
Speech and
language
therapists
Transcription
Without
context
3
Assessors
were unfamiliar
with
Parkinson’s
disease
Transcription
3
26
Transcription
Figure legends
Figure 1. PRISMA flow chart
27
Figures (600 dpi TIFF)
28
Supplementary data
Table of studies excluded at full-text screening with reasons
First author
Year
Title
Anderson
2013
Ash
2012
Baylor
2011
Berg
2003
Social problem
solving, social
cognition, and mild
cognitive
impairment in
Parkinson’s disease
The organization
and anatomy of
narrative
comprehension and
expression in Lewy
body spectrum
disorders
A qualitative study
of interference with
communicative
participation across
communication
disorders in adults
High-level language
difficulties in
Brown
2013
Calne
2003
Donovan
2007
Fusegi
2012
Griffiths
2013
Social participation
and speech
impairment in
Parkinson’s disease
The psychosocial
impact of late-stage
Parkinson’s disease
The communicative
effectiveness
survey:
Investigating its
item-level
psychometric
properties
The Unrelated
Communication
Interlude (UCI) – An
automatic behavior
phenomenon in
Parkinson’s disease
Potential causes
and consequences
of overlap in talk
29
Publication
details
Behav Neurosci
127(2): 184-92
Reason for
exclusiona
Not focused on
everyday
communication
Neuropsychology Not focused on oral
26(3): 368-384
medium
Am J Speech
Lang Pathol
20(4): 269-87
No explicit linkage of
either cognitive
status or intelligibility
to communicative
outcomes
Clin Linguist
Phon 17(1): 6380
J Med Speech
Lang Pathol
20(4): 30-35
Not focused on oral
medium
J Neurosci Nurs
35(6): 306-13
Article type
J Med Speech
Lang Pathol
15(4): 433-47
No explicit linkage of
either cognitive
status or intelligibility
to communicative
outcomes
Parkinsonism
Relat Disord
18(8): 986-9
Not focused on oral
medium
Semin Speech
Lang 33(1): 2743
No explicit linkage of
either cognitive
status or intelligibility
Not focused on
everyday
communication
Holtgraves
2010a
Holtgraves
2010b
Jaywant
2010
McNamara
2010
McNamara
2006
Martens
2011
Miller
2006
Monetta
2009
between speakers
with Parkinson’s
disease and their
familiar
conversation
partners
Pragmatic
comprehension
deficit in
Parkinson’s disease
Parkinson’s disease
and politeness
to communicative
outcomes
J Clin Exp
Neuropsychol
32(4): 388-97
Not focused on oral
medium
J Lang Soc
Psychol 29: 17893
No explicit linkage of
either cognitive
status or intelligibility
to communicative
outcomes
Not focused on
everyday
communication
Listener
impressions of
speakers with
Parkinson’s disease
Social cognition of
indirect speech:
Evidence from
Parkinson’s disease
Life goals of
patients with
Parkinson’s
disease: A pilot
study on
correlations with
mood and cognitive
functions
Assessment of
prosodic
communicative
efficiency in
Parkinson’s disease
as judged by
professional
listeners
Life with
communication
changes in
Parkinson’s disease
J Int
Neuropsychol
Soc 16(1): 49-57
Irony
comprehension and
theory of mind
deficits in patients
with Parkinson’s
disease
Cortex 45(8):
972-81
30
J
Neurolinguistics
23(2): 162-71
Not focused on oral
medium
Clin Rehabil 20:
818-826
Not focused on
everyday
communication
Parkinsons Dis
2011: Article ID
129310
Not focused on
everyday
communication
(impairment level
only)
Age Ageing
35(3): 235-9
No explicit linkage of
either cognitive
status or intelligibility
to communicative
outcomes
Not focused on oral
medium
Monetta
2007
Mott
2004
Pell
2006
Pitcairn
1990
Saldert
2014
Tremblay
2015
Tremblay
2014
Walshe
2009
Effects of verbal
working memory
deficits on
metaphor
comprehension in
patients with
Parkinson’s disease
Only
misunderstood?
The effects of
Parkinson’s disease
on interactions with
health professionals
The impact of
Parkinson’s disease
on vocal-prosodic
communication
from the
perspective of
listeners
Impressions of
parkinsonian
patients from their
recorded voices
Semantic trouble
sources and their
repair in
conversations
affected by
Parkinson’s disease
The effects of
subthalamic deep
brain stimulation on
metaphor
comprehension and
language abilities in
Parkinson’s disease
The role of
polysemy on
metaphor
comprehension
processing: The
example of
Parkinson’s disease
Dysarthria Impact
Profile:
Development of a
scale to measure
psychosocial
effects
31
Brain Lang
101(1): 80-9
Not focused on oral
medium
Aust J Prim
Health 10(2): 829
No explicit linkage of
either cognitive
status or intelligibility
to communicative
outcomes
Brain Lang 97(2): Not focused on
123-34
everyday
communication
(impairment level
only)
Br J Disord
Commun 25(1):
85-92
Not focused on
everyday
communication
Int J Lang
Commun Disord
49(6): 710-21
No explicit linkage of
either cognitive
status or intelligibility
to communicative
outcomes
Brain Lang 141:
103-9
Not separable from
surgical intervention
J
Neurolinguistics
30(1): 1-13
Not focused on oral
medium
Int J Lang
Commun Dis
44(5): 693-715
Results from people
with PD not
presented separately
Walshe
2008
Intelligibility of
dysarthric speech:
Perceptions of
speakers and
listeners
Int J Lang
Commun Disord
43(6): 633-48
Results from people
with PD not
presented separately
a = primary reason for exclusion listed for each excluded article - some articles could have been justifiably excluded for more
than one reason
32
Full Medline search strategy
(exp parkinson disease/)
AND
(exp cognition/ OR exp cognition disorders/ OR exp dementia/ OR exp memory/ OR exp
memory disorders/ OR exp neuropsychology/ OR planning.mp OR exp problem solving/ OR
exp executive function OR exp learning/OR exp social perception/ OR social cognition.mp
OR visuospatial function.mp OR exp speech disorders/ OR exp dysarthria/ OR speech
characteristics.mp OR exp speech acoustics/ OR exp speech intelligibility)
AND
(exp communication/ OR exp communication disorders/ OR pragmatics.mp OR
communicative effectiveness.mp or communicative participation.mp OR everyday
communication.mp OR social communication.mp OR conversation.mp)
This was translated for searches conducted on other databases
33
Detailed study characteristics
First
author
Year
Country
Design
Alpert
1990
USA
Crosssectional
Ash
2011
USA
Barnish
2013
Coates
Donova
n
Sizeb
Diagnostic
criteria for PD
Other inclusion
criteria
Participant
characteristics
10
Comme
rcially
funded
No
IPD (H&Y 3-4)
Crosssectional
14a
No
PD (Hughes
criteria)
Mild-to-moderate
dementia. No
psychiatric
conditions or
substance abuse
No other causes of
dementia
UK
Crosssectional
45
No
IPD (PDBB
criteria)
N = 10; male =
80%; Mean age =
77 years; mean
disease duration
(DUR) = 6 years
N = 14; male =
71%; Mean age =
73; DUR = 7
N = 45; male =
62%; age = 71,
DUR = 7 (median)
1997
UK
Crosssectional
48
Unknow
n
Clinically
diagnosed IPD
2008,
2005
USA
Crosssectional
25
No
PD (H&Y1-4)
34
No clinical evidence
of dementia or
previous serious
medical conditions
that could affect
cognition or speech.
Judged by clinics to
be suitable for the
study
No severe
intercurrent illness
or clinical evidence
of dementia
Aged between 18
and 90. No history
of neurologic,
psychiatric or
language deficit.
MMSE ≥23. Not
N = 48; male =
42%; age = 70;
DUR = 7
N = 25; male =
56%; age =70
Hall
2011
USA
Crosssectional
17
No
IPD (Gelb criteria)
Lesser
1999,
1999
UK
Mixed
methods
12
No
McKinla
y
2009
NZ
Crosssectional
40
No
PD and subcortical
dementia
(Cummings
criteria) or PD with
Lewy body
dementia (McKeith
criteria)
Clinically
diagnosed IPD
(specialist
neurologist)
35
H&Y stage 5.
Dysarthric but not
anarthric. Native
English speaker
who could read and
has sufficient
hearing to follow
instructions. Living
in the community.
Had to be able to
provide a control
participant
None
MMSE ≥ 25 and
premorbid IQ≥ 85.
No current
involvement in a
therapeutic trial,
history of moderateto-severe head
injury, stroke or
other neurological
impairment or
significant
psychiatric illness
requiring
N = 17; male =
71%; age = 61,
DUR = 8
N = 12; PD
subcortical
dementia male =
100%; age = 72;
PD with Lewy body
dementia male =
50%; age = 68
N = 40, age = 66
McNam
ara
2003
USA
Crosssectional
20
No
Miller
2011,
2008
UK
Cohort
104
No
Monetta
2008
Canada
Crosssectional
14
No
Pell
2014
Canada
Crosssectional
15
No
hospitalisation. No
major depression in
last 6 months (Beck
score >16). Not
currently taking
medication known to
affect CNS
Clinically
No clinical dementia
diagnosed PD
(DSM-III) or history
of substance abuse
or head injury. Male
and right-handed
IPD (PDBB
H&Y ≤ 3 at
criteria)
assessment. No
comorbid conditions
likely to affect
communication. No
DBS or SLT
treatment. Native
English speaking.
IPD (Calne criteria) No dementia (Mattis
scale), other serious
medical conditions
or history of
substance or
alcohol abuse
Clinically
No dementia (Mattis
diagnosed PD
scale), other
neurological
conditions, major
psychiatric
36
N = 20; male =
100%; age = 72;
DUR = 9
N = 104; age = 72;
DUR = 7
N = 14; age = 66
N = 15; male =
53%, age = 71;
DUR = 11
conditions or history
of alcohol abuse
a = outcome of interest was only studied in the PD dementia group (n = 14), b = sample size of all patients fulfilling inclusion criteria for this review. CNS = central nervous system, DBS = deep
brain stimulation, DSM = Diagnostic and Statistical Manual of Mental Disorders, DUR = disease duration, H&Y = Hoehn and Yahr scale, IPD = idiopathic Parkinson’s disease, MMSE = Mini Mental
State Examination, NZ = New Zealand, PD = Parkinson’s disease, PDBB = UK Parkinson’s Disease Society Brain Bank, SLT = speech and language therapy;, UK = United Kingdom, USA = United
States of America.
37
Detailed study results
First author
Year
Intelligibility measuresa
Cognitive
measuresa
Composite dementia
scale
Communicative
measures
WELMAR
Alpert
1990
None
Ash
2011
None
Comprehensive
neuropsychological
assessment
Analysis of
narration of story
Barnish
2013
AssIDS, conversational
sentence intelligibility
MoCA
CES, CPIB
38
Results
Dementia was negatively associated with
frequency of internal pauses (r = -0.53)
and frequency of simultaneous speech (r
= -0.53) and positively associated with
mean length of internal pauses (r = 0.58)
Reverse digit span was associated with
local connectedness (r = 0.61, p<0.05).
Letter-guided fluency was associated
with local connectedness (r = 0.70,
p<0.05) and search theme maintenance
(r = 0.60, p<0.05). Category fluency was
associated with local connectedness (r =
0.62, p<0.05) and search theme
maintenance (r = 0.64, p<0.05). Stroop
time was associated with search theme
maintenance (r = -0.70, p<0.05). No
other associations were significant
including all associations with global
connectedness.
Read sentence intelligibility (AssIDS) did
not predict CES or CPIB. Conversational
sentence intelligibility predicted CES (F =
13.65, p = 0.002, η2 = 0.43) and CPIB (F
= 4.96, p =0.04, η2 = 0.19). MoCA
predicted CPIB (F = 8.99, p = 0.005, η2 =
0.15) but not CES. With regard to MoCA
sub-domains, MoCA Naming predicted
CES (F = 4.07, p<0.05, η2 = 0.07) and
MoCA Executive and Visuospatial (F =
Coates
1997
Modified Y&B
Assessment Scale
None
Self-report
Donovan
2008,
2005
SIT, SSI
None
CES
Hall
2011
None
MMSE
RSPCS
Lesser
1999,
1999
None
Patients subdivided
into PD with
subcortical dementia
and PD with Lewy
body dementia
CAPPCI
McKinlay
2009
None
ID/ED from CANTAB,
Daneman and
Carpenter Reading
Span test, colour
naming, D-KEFS
TLC-E
McNamara
2003
None
FAS verbal fluency,
MMSE, Stroop,
Prutting and
Kirchner
39
3.22, p = 0.08, η2 = 0.05) and Attention
(F = 3.05, p = 0.09, η2 = 0.05) were
marginal predictors of CPIB
There was a significant difference in
intelligibility between those who
complained of difficulties communicating
with either strangers or family and friends
and those who did not (p<0.01)
There was a significant zero order
correlation between SIT and CES (r =
0.82, p<0.001) but not between CES and
SSI. SIT and SSI accounted for only 15%
of variance in CES.
MMSE was associated with RSPCS (r =
0.81, p = 0.002)
Overall, PD subcortical dementia and PD
with Lewy body dementia groups did not
differ with regard to CAPPCI parameters.
However, PD with Lewy body dementia
group had more difficulty orienting the
conversation partner to a new topic and
retained fewer pre-morbid
communicative situations
Working memory (Sobel’s z – 2.90,
p<0.01) and processing speed (Sobel’s z
= 3.40, p<0.001), but not attentional setshifting, explained deficits in pragmatic
functioning as indexed by TLC-E
according to path analyses
Stroop test (r = 0.63, p = 0.01) as well as
Tower of London time to first move (r = 0.46, p = 0.05) and time per move (r = -
Tower of London,
design fluency
Pragmatic
Protocol
Miller
2011,
2008
Speech intelligibility test
MMSE
Semantic
differential
questionnaire
Monetta
2008
None
Comprehensive
neuropsychological
assessment
Discourse
comprehension
test
Pell
2014
None
Comprehensive
neuropsychological
assessment
TASIT
0.50, p = 0.05) were associated with the
pragmatic protocol. No other significant
associations were found
Cognitive status was not associated with
greater perceived communicative change
at baseline or follow-up. There was a
weak but significant association between
communicative change and intelligibility
at baseline (r = -0.23, p = 0.03) but not
follow-up
Verbal working memory was associated
with the ability to draw inferences (r =
0.66, p<0.05) and answer questions
about stated details (r = 0.57, p<0.05).
Verbal fluency was associated with
ability to answer questions about implied
main ideas (r = 0.61, p<0.05) and stated
details (r = 0.56, p<0.05). No other
significant associations were found
The ability to make enriched social
inferences was associated with working
memory capacity (r = 0.74) and frontal
lobe functioning (r = 0.72)
a = only when used to assess relationships to outcome measures. AssIDS = Assessment of Intelligibility of Dysarthric Speech, CANTAB = CAmbridge Neuropsychological Test Automated Battery,
CAPPCI = Conversation Analysis Profile for People with Cognitive Impairment, CES = Communicative Effectiveness Survey, CPIB = Communicative Participation Item Bank, D-KEFS = Delis Kaplan
Executive Function System, FAS = Frontal Assessment Scale, ID/ED = Intradimensional/Extradimensional, MMSE = Mini Mental State Examination, MoCA = Montreal Cognitive Assessment, PD =
Parkinson’s disease, RCPCS = Rating Scale of Pragmatic Communication Skills, SIT = Sentence Intelligibility Test, SSI = Spontaneous Speech Intelligibility, TASIT = The Awareness of Social
Interference Test, TLC-E = Test of Language Competence – Extended, Y&B = Yorkston and Beutelman.
40