Original Research: Motor neuron disease: impact of decreased speech intelligibility on marital communication
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Vol 54 No 3S Afr Fam Pract 2012
Introduction
The lives of adults with acquired disorders and those of
their spouses are irreversibly altered as a consequence of
the onset of a progressive, degenerative illness, such as
motor neuron disease (MND). MND usually results in severe
disability involving all four limbs, speech, swallowing and
eventually breathing.
1
MND has an incidence of 1.5-2.5 per
100 000 of the population worldwide and predominantly
affects middle-aged and elderly people, with a mean age
of 65 years.
2
Average MND survival is generally reported to
range between two to ve years.
3
The International Classication of Functioning, Disability
and Health (ICF) provides a framework to describe the
impact of MND on levels of activity, participation, and
environmental and personal factors.
4
Persons with MND will
invariably experience a progressive decline in physical and
communication abilities. Relentless progressive muscular
weakness will negatively impact on individuals’ ability to
perform many physical activities of daily living until ultimately,
dependence is inevitable.
5
However, one of the most
profound changes that persons with MND will experience is
loss of their speech.
6
The rapid decline of speech function
as a result of dysarthria is common as 75% per cent of
persons with MND will reach a point where intelligible
verbal communication is no longer possible.
7
Dysarthria,
a motor speech disorder that results from damage to the
peripheral or central nervous system is characterised by
the imprecision of the movement of speech musculature,
resulting in decreased speech intelligibility.
8
Typically,
speaking rate is initially slower while speech intelligibility
remains relatively high, but as the disease progresses and
dysarthria becomes more apparent, speech intelligibility
decreases dramatically.
9
Speech intelligibility is seen as a signicant factor in
determining communication effectiveness
10
and is a critical
aspect in the assessment and monitoring of speech in
persons with MND.
5
Communication effectiveness implies
that an individual has an adequate level of communication
to meet important communication goals.
11
Abstract
Background: The onset of motor neuron disease (MND), a neurodegenerative disease, results in physical and
communication disabilities that impinge on an individual’s ability to remain functionally independent. Multiple aspects of the
marital relationship are affected by the continuously changing roles and responsibilities. Communication is one of the most
constructive ways of dealing with emotions that are elicited by these changes.
Method: This study explored the association between the deteriorating speech of persons with MND and couples’
perception of marital communication. Fourteen couples participated in this non-experimental correlational research study.
Data were collected over a 12-month period through the administration of objective and subjective measures.
Results: Results showed that despite decreased speech intelligibility, the relationship between the deteriorating speech
and the couples’ perception of marital communication was not statistically signicant.
Conclusion: Overall, the results proved that the supposition that communication between couples will invariably deteriorate
as a result of progressively reduced speech intelligibility is not necessarily valid. The fundamental importance of effective
communication in marriage is highlighted. It is well established that augmentative and alternative communication strategies
can preserve the ability to develop and maintain intimate rewarding relationships, even in the face of profound physical
disabilities.
Peer reviewed. (Submitted: 2011-10-01. Accepted: 2012-01-15.) © SAAFP S Afr Fam Pract 2012;54(4):332-338
Motor neuron disease: the impact of decreased
speech intelligibility on marital communication
Joubert K, PhD
Senior Lecturer, Department of Speech Pathology and Audiology, University of the Witwatersrand
Bornman J, PhD
Director, Centre for Augmentative and Alternative Communication, University of Pretoria
Correspondence to: Karin Joubert, e-mail: karin.joubert@wits.ac.za
Keywords: motor neuron disease, speech intelligibility, marital communication, augmentative and alternative communication, dysarthria, spouses
Original Research: Motor neuron disease: impact of decreased speech intelligibility on marital communication
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The positive relationship between speech intelligibility
and communication effectiveness in MND has been
conrmed.
7,12
This inevitable decline in the communication
function of persons with MND implies that in 80% of
cases, alternative communication strategies are required
to support the daily communication needs of persons with
MND and their families.
7
Augmentative and alternative communication (AAC)
strategies can preserve communication (and therefore
participation in everyday life situations), even in the face
of profound motor deterioration.
13
AAC is acknowledged
as best practice and is widely accepted among persons
with MND and their families.
14
A variety of strategies
are successfully used by persons with MND to facilitate
communication. These include unaided low-technology
strategies (e.g. facial expression, eye gaze, gestures
and sign language), aided low-technology strategies
(e.g. topic and alphabet cues and alphabet boards), and
high-technology strategies, such as dedicated AAC devices
(e.g. speech-generating devices, absolute head-tracking
and eye-tracking technology).
14
In light of the signicant
changes in the motor abilities of people with MND, it is
imperative that AAC strategies meet the changing physical
needs as the disease progresses.
9
Therefore, it is important
that the recommended strategies support multiple,
adjustable access methods that allow them to transition
from hand access to scanning and eye pointing or tracking,
for example.
9
Given its prominence over physical abilities and function,
communication is essential for the human experience and
may be the single most important aspect for personal
well-being.
11
As chronic illness is a dyadic affair, marriage
will predictably be affected by the diagnosis of MND.
Multiple aspects of the couple’s life will be affected and
their relationship will never be the same again. They will
experience similar psychosocial effects as they deal with
their own distress and that of their partner. Facing the
emotional trauma of losing their relationship elicits strong
emotions in both members. Guilt, anger, resentment
and frustration are often reported and couples facing the
stress of chronic illness must nd ways to manage these
emotions.
15
One of the most constructive ways of dealing
with these emotions is communication.
16
Sensitive, open, and direct communication plays a
central role in marriage and is essential for couples to
cope with chronic illness.
15-17
The ability of spouses to
listen, to express themselves clearly and accurately and
to understand each other is critically important in marital
communication.
18
This is achieved by the key characteristics
of marital communication, namely verbal (i.e. speech) and
nonverbal communication (i.e. gestures, facial expressions
and body language). Nonverbal cues qualify and colour
verbal communication, but can also occur independently
of it. Spouses, through their history of multiple shared
interactions, are expected to become sensitive to
each other’s facial expressions, idiosyncratic gestures,
vocalisations and feelings.
18
Therefore, self-exploration,
self-understanding and feelings of intense closeness are
facilitated by communication.
Negative life events, such as the onset of illness and/or
disability, disrupt the couples’ communicative competence.
With the onset of MND, couples’ communicative
competence is affected in a gradual way.
17
Both members
of the couple therefore need to move toward integrating
AAC techniques into a new lifestyle and learn to become
effective communicators in interactions that involve various
AAC strategies.
19
In the early stages of the communication
disorder, people with MND rely on residual speech to facilitate
social closeness with their spouse, but as their impairment
become more severe, multiple communication strategies
may be used for this purpose.
20
Interpreting the health and
disability status of MND in the context of environmental and
personal factors encourages a more holistic approach to
intervention that is focused on maximizing residual function,
altering the environment and educating families of people
with MND to ensure that they are provided the opportunity
to function optimally.
4
As there is a dearth of available information on how the
decline in speech intelligibility of persons with MND impacts
on marital communication, the primary aim of this study
was to compare how persons with MND and their spouses
perceive changes in their marital communication in relation
to the deteriorating speech of persons with MND. Firstly,
the current study aimed to describe the communication
abilities and speech intelligibility patterns of persons with
MND, and secondly, to describe the perception of marital
communication indicated by couples across the disease
progression.
Methodology
Research design
A non-experimental correlational design was employed to
study the relationship between the deteriorating speech of
persons with MND and the couple’s perception of marital
communication at three visits at six-monthly intervals over
a 12-month period.
Participant description
Fourteen couples (n = 28), divided into two groups,
participated in the study. Participant group 1 included
persons with MND (n
1
= 14), and participant group 2, their
spouses (n
2
= 14). Participants were recruited using a non-
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probability, purposive sampling strategy.
Participant group 1: Persons with motor neuron
disease
Only persons with MND with a neurologist-conrmed
diagnosis of MND who were in established intimate
relationships for at least 12 months prior to the onset of
MND, and who had no reported speech or language,
hearing or visual impairment other than those resulting from
the MND, were included in the study. This group comprised
11 males and three females. Six participants presented with
spinal-onset MND, six with bulbar-onset MND and two with
mixed-onset MND. The average age of the participants was
57;1 (years, months) [range 44;1 to 70;4; standard deviation
(SD) = 8;67]. The average time since the onset of the MND
symptoms was 3;76 (range 3 months to 8;6; SD = 2;19) and
the average time since diagnosis was 2;37 (range 5 months
to 7 years; SD = 2;08).
At the onset of the study, one participant’s MND
classication
20
was mild; seven participants were classied
as moderate, and six participants as severe. The disease
progression was apparent at both the second and third
visits (see Figure 1). The number of participants classied as
“moderate” decreased to four at the second visit, while there
was an increase in the number of participants classied as
“severe” to nine, with one classied as “terminal”. Attrition
of participants, as a result of death shortly after the second
visit decreased the sample size to only nine participants at
the third visit. Of these participants, only one was classied
as “moderate”, six as “severe” and two as “terminal”.
Participant group 2: Spouses
The second participant group comprised the 14 spouses (n
2
= 14) of the persons with MND in participant group 1. There
were 11 females and three males, and none reported any
communication, vision and hearing difculties that impacted
on their daily living activities. The average age of the spouse
group was 57;8 (range 47;6 to 70;3, SD = 8;64). Thirteen of
the couples were married for more than a decade, with an
average of 29;10 (range 3 years to 45;6; SD = 13;81).
Materials
Five validated measures were utilised to meet the
requirements posed by the research aims: classication
of MND,
21
Amyotrophic Lateral Sclerosis Severity Scale
(ALSSS) Speech Scale,
22
Sentence Intelligibility Test (SIT),
23
Modied Communication Effectiveness Index (CETI-M)
5
and the Primary Communication Inventory (PCI).
24
Classification of motor neuron disease
20
This classication system describes the severity of MND
across the functional modalities of speech, mobility and
the ability to use upper limbs for daily living activities.
21
Classication ranges between four states: mild, moderate,
severe and terminal.
Amyotrophic Lateral Sclerosis Severity Scale
22
Information was obtained regarding the severity level in
the four categories of swallowing, lower extremities, upper
extremities, and speech ability.
11,21
The ALSSS Speech
Scale
22
was used to describe the functional impairment
experienced by persons with MND in the area of speech for
this study. The 10-point scale of function includes ve general
categories namely normal speech processes, detectable
speech disturbance, the need for behavioural modications,
the need for use of augmentative communication and loss
of useful speech.
Sentence Intelligibility Test
23
This widely used standardised clinical transcription test
was used to objectively measure speech intelligibility of the
participants in group 1. A series of 11 randomly generated
unrelated sentences, varying in length from ve to 15 words,
were read by participants at each visit. Transcription of the
recorded responses yielded the percentage intelligible
productions.
Modified Communication Effectiveness Index
5
This measure of functional communication for persons with
MND uses a visual analogue for 10 contextual situations
on a 7-point Likert scale. The persons with MND and their
spouses completed the CETI-M
5
separately to determine
perceived communication effectiveness in the same
situations.
Primary Communication Inventory
24
The PCI,
24
a 25-item instrument, was designed to assess
marital communication. The PCI
24
was completed separately
by both members of the couple at all three visits. The overall
score appears to be a reliable indicator of the soundness of
communication between two members of a couple.
24
Procedures
Ethics approval for the study was obtained from University
of Pretoria’s research ethics committee. Written informed
100
Terminal
8642
Visit 3 Visit 2
Severe
Moderate
Mild
Visit 1
MND Classification
Number of perticipants
Figure 1: Motor neuron disease classication across visits
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Vol 54 No 3S Afr Fam Pract 2012
consent was obtained from the MND Association and all
participants, using established and approved methods. All
participants in the study were fully informed of the nature
of the study and were assured of condentiality and their
right to withdraw from the study at any time, without any
negative consequences. Participants were visited at home
at times indicated to be most convenient for both members
of the couple. During the rst visit, the aims of the research
were explained and consent was obtained. Demographic
information was acquired from the couple and the ALSSS
Speech Scale
22
and Classication of MND
21
were completed
by the researcher based on the clinical observations and
interviews with both members of the couple. Persons
with MND completed the following instruments with the
assistance of the researcher: SIT,
23
CETI-M
5
and PCI.
24
The
spouses completed the CETI-M
5
and PCI
24
privately after
clear instructions were given. The two subsequent visits
(visit 2 and visit 3) were scheduled at six-monthly intervals
at which the same measuring instruments as described for
visit 1 were administered.
Data analysis
Data were documented on all the relevant measuring
instruments and encoded according to data denitions.
Descriptive statistics were used to describe and analyse
the data. The Friedman test was used with the repeated
measures obtained from each participant group across the
visits, while the Spearman rank correlation (Rho) was used
to compute the correlation between speech intelligibility and
communication effectiveness; as well as speech intelligibility
and marital communication. The Wilcoxon test was used
to compare the differences between the communication
effectiveness ratings and marital communication scores of
persons with MND and their spouses. In addition, Cohen’s
d (effect size) was calculated to establish the size of the
statistically signicant difference.
Results
The rst aim addressed the description of communication
abilities and speech intelligibility patterns across the
disease progression. The second aim addressed couples’
perception of marital communication.
Communication abilities
Participants’ functional impairment in the area of speech
was established using the ALSSS Speech Scale.
22
The
progressive decline in speech function across all visits was
evident (see Figure 2). At the last visit, only one of the nine
participants reported a “detectable speech disturbance”,
three had to implement “behavioural modications”, three
used “augmentative communication”, and two reported
“loss of useful speech”. Participants who reported “use of
augmentative communication” and “loss of useful speech”
all facilitated communication with familiar and unfamiliar
partners through facial expression and partner-assisted
“yes” or “no” questions. During the last visit, none of the
participants made use of high technology AAC devices
for communication at the last visit due to a decline in their
functional motor abilities.
Speech intelligibility
At the initial visit, the mean percentage speech intelligibility
(as measured by the SIT
23
) for all participants was 75.58%
(range 35 to 100; SD = 22.93), which decreased to 53.07%
(range 0 to 93; SD = 32.81) at the second visit. This continued
to decrease to an average of 36.22% (range 0 to 73; SD =
24.6) at the last visit. A Friedman test (two-way analysis of
variance) was employed to determine whether the change
in speech intelligibility was statistically signicant over
time. A p-value of 0.0005 was noted, implying that there
was a signicant decrease in the speech intelligibility of
the persons with MND across the disease progression (see
Table I). Cohen’s d (d = 0.9168) conrmed that the effect of
the difference between the rst and third visit was large.
23
Table I: Percentage speech intelligibility across visits
Visit 1
n = 14
Visit 2
n = 14
Visit 3
n = 9
Mean 75.58
a
53.07
a,b
36.22
b
Standard deviation 22.93 32.81 24.6
Median 79.50 57.00 39.00
Cohen’s d 0.9168 (large)
Friedman p-value 0.0005
*
Means with different superscripts differ signicantly at the 5% level
*Signicance at the 5% level
Communication effectiveness
The CETI-M
5
was completed by both the persons with MND
(self-perceived) and spouses (listener-perceived) at each
visit. Ten communication situations, ranging from speaking
to familiar persons and strangers in a quiet and in a noisy
environment, to talking on the telephone, were rated. A
Figure 2: ALSSS scores across visits
8
7
6
5
4
3
2
1
0
Number of participants
Visit 1 Visit 2 Visit 3
Detectable speech disturbance
Behavioural modifications
Use of augmentative communication
Loss of useful speech
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Vol 54 No 3S Afr Fam Pract 2012
summary of the obtained results per participant group at
each visit, a comparison over time for each group, as well
as the difference between the two groups, is presented in
Table II.
Communication effectiveness as rated by persons
with MND
A Friedman test was employed to determine whether
the change in communication effectiveness, as rated by
persons with MND, was statistically signicant over time.
A p-value of 0.0458 was noted, implying a signicant
decrease in communication effectiveness between visit 1
and visit 3. The effect size as measured with Cohen’s d was
medium (d = 0.5821).
23
Communication effectiveness as rated by spouses
In order to determine whether the change in the
communication effectiveness of persons with MND as
rated by spouses was statistically signicant across the
visits, a Friedman test was employed. A p-value of 0.0151
was noted, implying that, similar to the persons with MND
rating, a statistically signicant decrease in communication
effectiveness was found between visit 1 and visit 3. Cohen’s
d indicated that the size of the effect was medium (d =
0.6387).
23
The difference in CETI-M
5
ratings between persons with
MND and spouses at each of the three visits was determined
using a Wilcoxon test. As evident from the p-values (0.2578,
0.0980 and 0.5078, respectively), no statistical signicance
at the 5% level was identied (Table II). A comparison of
CETI-M
5
ratings of persons with MND and spouses over
time was determined by employing a Friedman test. A
p-value of 0.8948 was noted, indicating no difference in
ratings between the two participant groups over time.
Marital communication
The PCI
24
was administered at each visit to both participant
groups. The PCI
24
scores have a possible range of 25 to125.
Higher scores are indicative of better or more positively
viewed marital communication. The mean scores are 105
for “happily” married couples, and 81 for “unhappily”
married couples.
24
Overall, the mean scores of marital communication as
perceived by the persons with MND group were consistently
higher than those of the spouse group at all three visits. It
is important to note that the mean PCI
24
scores obtained
at the rst visit for both these groups were below 105 (the
mean score for “happily” married couples). The mean
scores decreased across the visits. At the rst visit, scores
were similar, but the decrease became more marked in the
spouse participant group at visit 2 and visit 3, indicating a
steady decline to a score of “unhappily” married. At each
visit, a summary of the results obtained per participant
group, a comparison over time for each group, as well as
the difference between the two groups, was recorded, and
is presented in Table III.
Perception of marital communication as rated by
persons with MND
A Friedman test was employed to determine whether the
change in the perception of marital communication as rated
by persons with MND was statistically signicant over time.
Table II: Communication effectiveness (CETI-M
5
) ratings across visits and between participant groups
Visit 1
n = 14
Visit 2
n = 14
Visit 3
n = 9
Cohen’s d Friedman
p-value
Mean SD*** Mean SD Mean SD
Persons with motor neuron disease 31.40
a
12.04 24.5
a,b
10.25 21.00
b
6.84 0.5821* 0.0458*
Spouses 28.53
a
11.54 20.8
a,b
9.74 18.77
b
9.30 0.6387** 0.0151*
Difference 0.6835 0.2812 0.1719 0.8948
Wilcoxon p-value 0.2578 0.0980 0.5078
Means with different superscripts differ signicantly at the 5% level.
* Signicance at the 5% level ** Between visit 1 and visit 3: medium-effect size *** standard deviation
Table III: Marital communication across visits, and between participant groups
Visit 1
n = 14
Visit 2
n = 14
Visit 3
n = 9
Cohen’s
d
Friedman
p-value
Mean SD*** Mean SD Mean SD
Persons with motor neuron disease 87.99 14.15 86.00 12.54 85.22 18.49 - 0.8233
Spouse 87.73 16.02 83.93 16.91 79.44 16.74 0.5562** 0.0446*
Difference
0.9134 0.4966
0.5078
0.2359
Wilcoxon p-value
0.7763 0.6374
0.0576
* Signicance at the 5% level ** Between visit 1 and visit 3: medium-effect size *** standard deviation
