Learning Outcomes: As a result of this activity, the reader will be able to (1) describe the concept
of mental practice using motor imagery; (2) summarize previous findings of mental
practice and improved motor outcomes; (3) discuss current perceived advantages and
limitations of implementing mental practice in dysphagia rehabilitation.
Dysphagia is the medical term for a swallowing impairment. Dysphagia often results
from functional or structural abnormalities of the head and neck, and/or esophagus,
as well as from damage to the central and peripheral nervous systems. A swallowing
impairment can lead to serious medical complications. Furthermore, a swallowing impairment
appears to affect more than the person with dysphagia.[1]
[2] Stroke, Parkinson's disease, head and neck cancer, and dementia represent some of
the more common etiologies of dysphagia.
Management of dysphagia is often behavioral, with a compensatory and/or restorative
focus.[3] Diet modification and other compensatory strategies are used more as immediate strategies
to improve the safety and/or efficiency of swallowing during oral intake. However,
quality of life and compliance issues often accompany compensatory approaches like
diet modification.[4] Behavioral interventions, such as exercise programs to induce changes in the strength,
speed, and timing of musculature important to swallowing, have a restorative focus
and some show promise.[5]
[6] Optimal approaches in restorative approaches like exercise programs have yet to
be determined and continued efforts to elucidate the most effective methods are critical.[7] Drawing from literature in the sports sciences and rehabilitative medicine (occupational
and physical therapies) realms may prove beneficial in discovering methods for enhancing
the effectiveness of rehabilitative exercises related to swallowing.
One restorative approach currently used and researched within these realms is mental
practice (MP) with motor imagery. Motor imagery is the voluntarily driven and self-generated
mental representation of a motor task during which there is no overt output.[8]
[9]
[10]
[11] MP using motor imagery means rehearsing the motor imagery task in a repeated manner
or put simply, practicing the motor imagery task.[12]
[13]
[14]
[15] Improved motor performance outcomes have been shown with implementation of MP, particularly
alongside physical exercise of the same motor task as compared with physical exercise
alone, and MP alone may also be beneficial when physical exercise is not feasible.[16]
[17]
[18]
[19] Rehabilitative medicine intervention approaches like physical practice capitalize
on the plastic nature of the cortex in sensorimotor learning. Neural reorganization
has been shown with MP in healthy and patient populations, as similar neural areas
are activated during motor imagery as during actual motor execution of a task.[20] From a practice perspective, MP constitutes an attractive therapeutic approach because
it does not require physical exertion, it can be performed without direct supervision,
and it requires minimal expense and equipment.[21]
Research on clinical implementation of MP is growing quickly in disciplines such as
cognitive neuroscience, sport psychology, and other disciplines involving motor learning,
in addition to medical and rehabilitation science.[14] Speech-language pathology (SLP) is situated in an exciting position within this
interdisciplinary area of interest, as knowledge specific to MP and SLP is limited,
but the promising clinical potential is starting to be recognized and explored.[21]
[22] For example, investigation of improving lingual strength in typically aging individuals
using MP have been initiated, though research in persons with dysphagia is needed.[22] Researchers are also starting to consider application of MP for motor speech impairment
poststroke, highlighting the decades of evidence in other fields to support investigation
of MP incorporation in management plans.[21] Specific to the area of dysphagia rehabilitation, there is a growing body of evidence
showing similar neural substrates are shared between motor imagery and motor execution
of swallowing and swallowing-related tasks, as well as supporting the potential benefit
in using MP as a clinical tool.[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30] For example, Kober and colleagues have shown that swallowing in motor imagery form
activates much of the swallowing network throughout the entire brain, suggesting that
future studies are needed in persons with dysphagia.[25]
Given the promising trends for using MP in dysphagia rehabilitation, we need to better
understand the current knowledge and practice, as there is a low presence of this
topic in SLP literature, discussion boards, and/or conference sessions. The present
study specifically aims to (1) measure the current knowledge and implementation of
MP by SLPs in the area of dysphagia treatment, (2) reveal the perception of the utility
of MP and its potential effectiveness, and (3) gain a more current understanding of
other types of therapy that are most popular for dysphagia treatment. This is critical
to identify interest in MP, gaps in knowledge and training, and needs moving forward
for research and clinical training with MP in dysphagia.
Methods
Recruitment
Institutional Review Board approval was obtained from both principal investigators
(S.S. and C.N.) universities. A convenience sample of SLP participants was recruited
via email, alumni social media groups, and American Speech-Language-Hearing Association
(ASHA) Special Interest Group 13 (SIG-13). A message containing the URL link for the
survey was posted to the social media groups and ASHA SIG-13 Community Forum. SIG-13
and social media groups were selected based on their focus on medical settings and
swallowing disorders. The URL link took SLPs to the consent form. The informed consent
process was presented and granted electronically prior to initiating the survey. Participation
in the survey was voluntary and responses were anonymous to the investigators. All
potential participants were privy to the participating universities' names and principal
investigator's names/credentials. It is unknown if prior relationships existed between
the principal investigators and participants, as respondents were anonymous to the
investigators.
The inclusion criteria for this study were that participants have at least a master's
degree in the field of SLP and be a fully licensed, practicing SLP. Individuals from
countries outside of the United States were permitted to participate if they had the
equivalent of a license for their country. Participants were also required to work
with patients with dysphagia for an average of 1 hour per day. SLP assistants were
excluded from this study as they are not involved in developing intervention plans.
Survey
A survey was developed and disseminated using an online survey platform (Qualtrics,
Provo, UT). Questions for the survey were written based on current MP with motor imagery
literature review and the principal investigators' clinical experiences in medical
SLP. The questions in the survey were created in collaboration between the research
teams at each university. The survey was then reviewed by a university department
with expertise in survey development. Modification of the survey involved development
of unique branches of the survey dependent on a participant's current use of MP in
dysphagia management. To ensure a brief yet thorough survey experience, with the hope
of increasing response rate, the survey was developed so that it could be completed
in 15 minutes or less.
Prior to voluntarily agreeing to participate in the survey study, participants were
provided a brief summary to review. The summary first defined motor imagery and MP,
then briefly discussed how MP has been implemented in other disciplines (i.e., physical
and occupational therapies). Specific examples were provided to demonstrate what type
of motor skills may be visually and kinesthetically imagined using MP. The summary
ended with a description of how MP may be applicable to the field of SLP. See Appendix A to review the complete survey.
The survey began with a core of similar questions for all participants concerning
current level of knowledge of motor imagery. All participants were also asked what
intervention techniques they use with persons with dysphagia and if they may be willing
to incorporate MP into their patients' management plans. The survey then branched
into two sections with questions for those who use MP with their patients and those
who do not. Those who use MP in therapy were asked questions regarding therapy tasks,
determining patient candidacy, scheduling, monitoring patient progress, perceived
advantages of MP, and perceived limitations of MP. Those who do not use MP in therapy
were asked questions regarding the extent to which they think MP could potentially
benefit their patients and what factors may affect their decision to implement this
approach. All participants were asked demographic questions at the end of the survey.
Participants were allowed to voluntarily skip any question they did not want to answer.
Data Collection
Data were anonymously collected and stored either in Qualtrics or separately on a
password-protected laptop. The survey accepted responses for 30 days to allow interested
SLPs to participate if willing. No identifying information or protected health information
was collected and no physical records were collected. The electronic consent form
was presented on the first page of the Qualtrics survey.
Data Analysis
Descriptive data were used to report single- or multiple-option questions. Open-ended
questions were analyzed using inductive coding. Coding was initially performed by
two student investigators, with triangulation of coding performed by the two senior
principal investigators. Codes for each open-ended question were derived from participant
responses—using their own words. Codes were then categorized into emerging themes
to support greater understanding of SLPs' perceived benefits and challenges regarding
MP.
Results
Demographic Survey Questions
All respondents were asked final demographic questions to better understand the context
of those responding to the survey. A total of 99 responses were collected for the
survey, yet 151 settings were reported, indicating SLPs working in multiple settings.
Settings included inpatient acute care (n = 49, 32%), inpatient rehab (n = 32, 21%), outpatient (n = 25, 17%), skilled nursing (n = 25, 17%), private practice (n = 6, 4%), and school (n = 2, 1%). Twelve (8%) reported “Other” settings and 11 were listed. These included
long-term acute/long-term hospital (n = 3), geriatric home health (n = 3), assisted living facility (n = 1), early intervention home health (n = 1), community transitional care (n = 1), university clinic (n = 1), and outpatient pediatrics (n = 1).
[Fig. 1] displays the types of populations the SLPs reported working with most often. Those
listed under “Other” (n = 15) included head and neck cancer (n = 8), spinal cord injury (n = 3), trauma/surgery (n = 2), trach/vent (n = 1), hip fracture (n = 1), transplant (n = 1), oncology (n = 1), critically ill (n = 1), postintubation (n = 1), debility (n = 1), head and neck injuries (n = 1), and voice (n = 1). The majority of SLPs spend 2 to 4 hours per day with clients with dysphagia
(n = 42, 49%), followed by 5 to 7 hours (n = 28, 33%), greater than or equal to 8 hours (n = 11, 13%), and less than or equal to 1 hour (n = 5, 6%) (n = 86). Most respondents reported co-treating: with occupational therapists (n = 51), with physical therapists (n = 46), with physicians (n = 25), with psychologists (n = 7), with behavioral therapists (n = 3), and with teachers (n = 2). Three other professionals were listed for co-treating: CNAs, neuropsychologists,
and dietitians. Three SLPs stated “only occasionally,” they do not “co-treat, but
collaborate with physicians and other therapies,” and one stated early intervention
co-treating is not reimbursable in his/her state. There were no reports of co-treating
with audiologists. Ten (12%) of the respondents were board-certified specialist-swallowing
(BCS-S; n = 85). Over one-third of the SLPs (n = 34, 40%) had 11 or more years of experience, followed by 4 to 6 years (n = 22, 26%), and equal amounts for 7 to 10 and 0 to 3 years (n = 15, 17% each) (n = 86). Sixty-four (74%) SLPs were interested in learning more about MP, 18 (21%)
were “not sure,” and 4 (5%) reported no interest in learning more (n = 86).
Figure 1 Most common patient populations worked with speech-language pathologist participants.
TBI, traumatic brain injury.
Eighty-six SLPs reported the state in which they were practicing, which the investigators
divided into regions of the USA: South (n = 28, 33%), Midwest (n = 23, 27%), West (n = 19, 22%), and Northeast (n = 16, 19%). There were 17 states which were not represented; these were primarily
in the Pacific, Mountain West, West North Central Midwest, and South Atlantic regions.
The investigators were contacted by at least one potential respondent from Europe
who was told he or she could participate in the survey as long as he or she held the
equivalent of licensure in his or her country. It is unknown whether this person participated.
The vast majority of respondents were female (n = 80, 93%), with 5 (6%) males responding, and 1 (1%) individual who preferred not
to answer (n = 86). Caucasian was the predominant race/ethnicity (n = 73, 85%), followed by those who preferred not to answer (n = 5, 6%), Hispanic (n = 3, 4%), Asian (n = 2, 2%), and African American (n = 1, 1%). Two (2%) respondents reported “Other,” with one identifying as mixed race/ethnicity.
No respondents selected “American Indian or Alaska Native” or “Native Hawaiian or
Pacific Islander” (n = 86). Over half of the SLPs were between 20–29 and 30–39 years of age, with 23 (27%)
and 29 (34%) in each group, respectively. Sixteen (19%) were 40 to 49 and there were
9 (10%) each in the 50 to 59 and 60 or older groups (n = 86).
Core Questions for All Participants
Twenty-two respondents (22%) were familiar with MP with motor imagery exercise, while
47 (48%) were not and 30 (30%) reported being somewhat familiar (n = 99). The number of participants refusing to volunteer is unknown. Seven (7%) reported
knowing other SLP colleagues who use MP and 19 (19%) reported knowing professionals
from other disciplines who use it (n = 99). Over half of the participants (n = 54, 55%) believed their patients would be willing to incorporate MP with their
dysphagia management plan, with 37 (37%) being unsure, and 8 (8%) responding “No”
(n = 99). [Fig. 2] displays the most common techniques that the SLP participants indicated as used
for dysphagia rehabilitation. Of the six “Other” responses, ice chips, chin tuck against
resistance (n = 2), high-resolution manometry, shaping and behavioral reinforcement, and modified
Frazier free water protocol were given. Sixteen (16%) SLPs reported having used MP
with a patient before and 83 (84%) reported not having used it (n = 99).
Figure 2 Most common dysphagia treatment techniques reported.
Respondents Who Have Not Used Mental Practice
Respondents who do not use MP were asked their clinical opinion for potential applicability,
use as a supplemental approach, and anticipated patient response if they were to use
MP (n = 83). Understanding of MP was based on the descriptive information provided at the
beginning of the survey (see Appendix A) and any previous understanding they had acquired prior to taking the survey. The
majority of responses to these clinical opinion questions were a “small” to “moderate”
degree. [Fig. 3] displays these results. Factors affecting the likelihood to implement or try MP
included (participants could select all that apply) more evidence in the literature
(n = 63, 76%), self-efficacy for patient (n = 53, 64%), ease of implementation (n = 39, 47%), perception by others in their field (n = 16, 19%), and “Other” (n = 8, 10%). “Other” responses primarily centered on the ability of the patient to
participate (e.g., acutely ill, cognitive limitations, age/pediatrics), with limited
time for treatment being listed by one respondent.
Figure 3 Clinical opinion for usefulness, applicability, and patient responsiveness to mental
practice.
SLPs were asked in an open-ended question to provide any perceived challenges that
would deter them from implementing MP. Sixty-nine respondents addressed this question,
with a total of 124 responses given. Their responses were inductively coded. The most
common perceived challenge that emerged was cognitive level of patient/multiple handicaps
(n = 35), followed by patient motivation/participation/attitude (n = 17), lack of clinician knowledge/training (n = 12), lack of research (n = 11), determining patient imaging ability (n = 4), pediatrics/client's age (n = 3), insufficient therapy time (n = 2), and distracting treatment environment (n = 1). One respondent was unsure, while another said there were no perceived challenges
that would deter them from implementation (see [Fig. 4]).
Figure 4 Codes organized by themes for factors deterring mental practice implementation.
Respondents Who Have Used Mental Practice
Four SLPs using MP distinguish between external and internal motor imagery (n = 9). Respondents reported using MP with a variety of traditional dysphagia therapeutic
approaches (see [Fig. 5]), with “Other” described as voice therapy. Seven SLPs alternate between mental and
physical exercise repetitions or sets within a session, three divide the session into
two parts (mental and physical exercise), two encourage only mental exercise outside
of therapy sessions, and one reported alternating days of mental and physical exercise.
One specified providing initial training and reiteration education as needed. The
typical schedule for patients using MP was reported by three SLPs to be three to five
times per week, three reported several times per day, two reported twice per day,
with another two selecting daily, and one indicating less than three times per week
(n = 11). [Fig. 6] displays how respondents monitor patient progress and performance outcomes, with
the “Others” being reported as Expiratory Muscle Strength Trainer/Penetration-Aspiration
Scale changes and not monitoring effects of MP.
Figure 5 Most common dysphagia treatment approaches used with mental practice.
Figure 6 Methods used to measure patient progress and performance outcomes of mental practice.
Respondents reported that MP was advantageous to their patients to a very high degree
(n = 1), high degree (n = 4), moderate degree (n = 4), and small degree (n = 2). They indicated that their patients responded to MP with a high degree (n = 1), moderate degree (n = 7), and small degree (n = 3). No respondents selected “Not at all” for either level of advantage or patient
responsiveness. SLPs indicated several perceived advantages of using MP: safe for
NPO (nil per os) patients (n = 6), ease of use for patient (n = 6), patient independence (n = 5), can be replicated or accessed at home (n = 5), patient confidence (n = 3), easy for SLP to demonstrate (n = 3), and patient may be familiar with technique from other disciplines and types
of therapy (n = 2). One “Other” response was provided: increased practice time without fatigue.
Perceived limitations of using MP were also identified: hard to monitor patient's
mental technique (n = 9), requires sustained attention (n = 7), lack of patient understanding (n = 7), patient compliance (n = 5), not commonly used (n = 5), and not enough evidence-based research (n = 4). One “Other” response described concern of the SLP's own limited knowledge.
Respondents were asked via an open-ended question how they determined if a patient
was a good candidate for MP. The 17 unique content units from the 10 respondents who
completed this question were inductively coded. The greatest determiner was cognitive
level of patient (n = 5), followed by ability to follow directions (n = 4), receptiveness/motivation of patient (n = 4), judgement of clinician (n = 3), and attendance (n = 1). The minimal number of codes and respondents limited organization into themes;
however, three potential themes were noted: disorder-related factors, intrinsic patient
factors, and circumstantial (see [Fig. 7]).
Figure 7 Potential themes for determining patient candidacy.
Qualitative Analysis
Interviews were not conducted; so, theme emergence was limited. However, the two open-ended
questions analyzed earlier provide us with a deeper glimpse into patient candidacy
and perceived challenges in using MP. The open-ended questions explored two unique
questions (i.e., limitations for implementation and patient candidacy), but revealed
overlapping emerging themes, as these topics are ultimately related. All the themes
regarding patient candidacy ([Fig. 7]) are related to patient engagement, and therefore merge well with the largest theme
that emerged from perceived limitations ([Fig. 4]). The themes have been revised slightly to more appropriately represent both patient
candidacy considerations and perceived limitations jointly.
The first emerging theme involves factors that SLPs perceive to affect patient engagement.
For example, responses show a primary concern for ability of the patient to mentally
engage in MP. One respondent stated MP would be appropriate, “ideally if they have
cognition and memory for independent practice between sessions.” Another shared, “many
of my clients have cognitive impairments, which would likely impact ability to do
MP.” While the presence of multiple handicaps was given as a perceived limitation,
one SLP who uses MP shared that “profound dysphagia that makes traditional swallowing
treatments more challenging” was a positive candidacy marker. Therefore, physical
limitations, as well as cognitive, are perceived to affect patient engagement. Emphasis
was placed on whether the patient was “receptive to the concept,” “familiar with MP
in other aspects of their lives,” and “motivated.”
The second emerging theme involves evidence-based practice concerns, highlighting
the lack of clinician knowledge and training, as well as the need for more research
in this area. Respondents asked, “Is it research based? Will it improve outcomes?”
They admitted they would “want to read the research first to assure [themselves] of
the validity and efficacy of this approach.” Subsequently, it would be important to
“completely [understand] how to teach a patient how to complete [MP] successfully.”
One SLP who reported using MP admitted that they “did not even know that this was
a therapy technique,” which suggests that other SLPs may be using some concepts of
MP without even knowing it. Finally, a third emerging theme of therapeutic environmental
factors involved respondents noting factors such as insufficient therapy time and
distracting therapeutic environments. One SLP expressed that he or she had “limited
access to a low stim environment for working with residents,” because MP may warrant
a quiet environment until the patient acclimates to the technique.
Discussion
General demographic data indicate that most survey participants were female, Caucasian,
younger than 40 years, and working in multiple settings mainly with patients with
a neurogenic etiology of dysphagia, with patients poststroke representing the largest
category. The majority of SLP participants appear to use compensatory strategies and
rehabilitative exercises with patients, with less focus on neuromuscular electrical
stimulation and device-focused therapies. These data contribute to a better understanding
of current dysphagia rehabilitation in general.
The most significant findings of the present survey study are the current interest
in and familiarity with MP using motor imagery exercise. Nearly 75% of participants
are interested in learning more about MP, over half are already at least somewhat
familiar with the concepts of MP, and nearly a quarter of the respondents are already
incorporating MP into their clinical practice. These participants represent a group
of underserved SLP clinicians—in other words, SLPs with the desire to use a clinical
tool but lacking access to evidence-based research, training, and education in the
area of MP. Further investigation in this area would help address this need and provide
evidence-based guidance to SLPs interested in incorporation of MP into management
plans. Of those including MP already, none reported that MP was “not at all” useful
for their patients; rather, all noted some level of advantage for their patients.
This group also primarily used MP alongside traditional strengthening exercises. However,
a low number responded to the question about how progress was monitored with patients
and various dosing strategies were presented, further indicating the need for evidence-based
guidance.
Close and open-ended responses to questions regarding perceived advantages, perceived
limitations, patient candidacy, and factors affecting the likelihood to implement
MP appeared to express repeated considerations important to our respondents. When
responding to close-ended questions, respondents selected options that closely paired
with those given in open-ended questions. Inadvertent leading of responses may have
occurred due to survey item order. Open-ended questions were presented after closed-answer
questions. However, the repeated emphasis on evidence-based practice, patient motivation,
and patient's ability to participate provide a level of confidence in the data via
triangulation.
In addition to the high level of interest in MP demonstrated by the survey respondents,
these collective, perceived concerns point to the need for training about how to appropriately
assess a patient's imaging ability (e.g., assessing cognitive ability, language ability,
standardized imaging questionnaires, mental chronometry) and for a better understanding
of which populations may benefit from inclusion of MP exercise in therapy. For example,
imaging ability in the stroke population appears to improve within a few weeks postinjury,
and the need to reassess imaging ability with this population is important.[31] Patients with Parkinson's disease, a progressive neurological condition with associated
deficits in control and motor learning, also appear to have well-preserved motor imaging
ability prior to the late disease stage.[32] The current investigators are unsure about specific sources for current knowledge
of MP claimed by a large number of respondents, though interaction with other disciplines
appears to be a potential source. However, the high level of interest in the present
preliminary data and emerging evidence involving the use of MP in the area of dysphagia
signals the need for increased support, evidence, and training opportunities for SLPs
specifically interested in implementing MP exercise concepts in intervention management
plans.[22]
[24]
[25]
[26]
[27]
[28]
[30]
Limitations
These data are best viewed as preliminary findings given the small sample size of
survey respondents. The sample of participants in the present survey study represents
the different geographic regions of the United States fairly well; however, more information
is needed from the Pacific, Mountain West, Midwest, and South Atlantic regions of
the United States as well as data from different countries, to better understand any
relationship between geographical location and knowledge/practice patterns of MP.
The survey did not allow for a deeper exploration via interviews, as broad survey
reach across the United States was important for this initial exploration. The present
study's sample, which represented a cross-section of individuals drawn from across
the United States, provided a preliminary understanding of MP in the area of dysphagia.
However, specific group comparisons were not made as many questions were not designed
for more specific comparison using statistical analysis and respondent groups were
not distributed well for meaningful comparison.
Regarding the implementation and knowledge of MP, two limitations are noted. First,
even though we provided a frame of reference regarding MP using motor imagery at the
start of the survey, it is probable that respondents have varying ideas about this
concept as it is new to the field of SLP. Second, the benefits of MP from participants
were subjectively reported, without further explanation of how such benefits were
measured. While practitioner expertise and patient preferences are part of evidence-based
practice, the component of research evidence (well-designed efficacy studies) is necessary
to comprehensively support MP in clinical practice.
