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Aphasiology
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Music in the treatment of
neurological language and speech
disorders: A systematic review
a
a
Joost Hurkmans , Madeleen de Bruijn , Anne M. Boonstra
a
b
b
c
, Roel Jonkers , Roelien Bastiaanse , Hans Arendzen &
Heleen A. Reinders-Messelink
a
a
Rehabilitation Center “Revalidatie Friesland”,
Beetsterzwaag, The Netherlands
b
School for Behavioural and Cognitive Neuroscience (BCN),
University of Groningen, Groningen, The Netherlands
c
Leiden University Medical Center, Department of
Rehabilitation Medicine, Leiden, The Netherlands
Available online: 06 Oct 2011
To cite this article: Joost Hurkmans, Madeleen de Bruijn, Anne M. Boonstra, Roel Jonkers,
Roelien Bastiaanse, Hans Arendzen & Heleen A. Reinders-Messelink (2012): Music in the
treatment of neurological language and speech disorders: A systematic review, Aphasiology,
26:1, 1-19
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APHASIOLOGY, 2012, 26 (1), 1–19
Music in the treatment of neurological language and speech
disorders: A systematic review
Joost Hurkmans1 , Madeleen de Bruijn1, Anne M. Boonstra1,
Roel Jonkers2, Roelien Bastiaanse2, Hans Arendzen3,
and Heleen A. Reinders-Messelink1
Downloaded by [University of Groningen] at 07:32 14 February 2012
1
Rehabilitation Center “Revalidatie Friesland”, Beetsterzwaag, The Netherlands
School for Behavioural and Cognitive Neuroscience (BCN), University of
Groningen, Groningen, The Netherlands
3
Leiden University Medical Center, Department of Rehabilitation Medicine,
Leiden, The Netherlands
2
Background: Acquired brain injury resulting from a stroke can result in impairments in,
among other things, communication. Music therapy has been used in rehabilitation to
stimulate brain functions involved in speech. The use of elements of music is well known
and more often used in the treatment of aphasia and apraxia of speech.
Aims: The aim of the study is to synthesise studies on the effect of music parameters in
the treatment of neurological language and speech disorders. In addition, possible mechanisms that explain recovery are investigated.
Methods & Procedures: Search terms were formulated based on the research question.
A systematic search in databases was performed using these search terms. Then inclusion
criteria were formulated and articles meeting the criteria were reviewed on patient characteristics, interventions, and methodological quality.
Outcomes & Results: A total of 1250 articles have been selected from the databases, of
which 15 were included in this study. The Melodic Intonation Therapy was the most
studied programme. Melody and rhythm were the music interventions that have been
applied the most. Measurable recovery has been reported in all those reviewed studies
using music in the treatment of neurological language and speech disorders. In three
studies research was also conducted into the mechanisms of explanation of the measured
recovery. However, the methodological quality of the investigated studies was rated as
“low”, using the ASHA level of evidence indicators for judging research.
Conclusions: Although treatment outcomes were reported as positive in all of the
15 reviewed studies, caution should be used relative to conclusions about the effectiveness of treatments that incorporate components of music with neurologically impaired
individuals. Methodological quality was rated as low and interpretations of mechanisms of recovery were contradictory. Suggestions for standardising and improving
methodological quality drawn from the analysis are presented.
Keywords: Music; Speech disorders; Treatment.
Address correspondence to: Joost Hurkmans, MA, Rehabilitation Center “Revalidatie Friesland”,
P.O. Box 1, 9244 CL Beetsterzwaag, the Netherlands. E-mail: [email protected]
A revised version of this article has been published in a Dutch journal (Stem Spraak- en Taalpathologie).
© 2012 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business
http://www.psypress.com/aphasiology
http://dx.doi.org/10.1080/02687038.2011.602514
Downloaded by [University of Groningen] at 07:32 14 February 2012
2
HURKMANS ET AL.
Musical structures and language structures have many similar features, which generates continuous research interest. Studying the relation between these two entities
dates back to the nineteenth century. Gamer (1892) studied animal noise and the
human voice and transformed these sounds to musical instruments like piccolo
and other flutes. More recently, sophisticated techniques like event-related potential (ERP), positron emission tomography (PET), and functional magnetic resonance
imaging (fMRI) have been used to study perceptual elements of music and language in
order to gather information on the functional and neural architecture of both domains
(Brown, Martinez, & Parsons, 2006; Jeffries, Fritz, & Braun, 2003; Patel, 2003).
Communication impairments resulting from neurological damage were already
being studied in the nineteenth century. Broca (1861) reported language disorders in
patients who suffered from a stroke. In 1914 Déjérine, as one of the first researchers,
observed a superior singing ability in aphasia. Subsequently, more researchers
reported data relative to severely impaired patients who barely had the ability to speak
in spontaneous speech, but were able to produce well-articulated, linguistically accurate words while singing familiar songs that had been learned prior to their stroke
(e.g., Cohen & Ford, 1995; Gerstman, 1964; Hébert, Racette, Gagnon, & Peretz,
2003; Racette, Bard, & Peretz, 2006; Straube, Schultz, Geipel, Mentzel, & Miltner,
2008). Clinical applications using musical elements were then a natural consequence
in aphasia intervention. Melody and rhythm have been used by non-fluent speakers to enhance speech production or to improve speech fluency. The most common
therapy intervention using melody and rhythm is the Melodic Intonation Therapy
(MIT; Albert, Sparks, & Helm, 1973). MIT consists of speaking with a simplified
and exaggerated prosody, characterised by a melodic component (two notes, high and
low) and a rhythmic component (two durations, long and short). Various music therapy approaches are aimed at verbal expression and communication as well. Therapy
methods using different musical elements, like melody, rhythm, dynamics, tempo, and
metre, to regain speech production need not automatically contain music therapy. For
example, the MIT is not a therapy of music as indicated by the original developers of
the treatment approach.1 However, several music therapy variations have been developed mostly based on MIT principles (e.g., Modified Melodic Intonation Therapy,
MMIT, Baker, 2000; and Singen Intonation Prosodie Atmung Rhytmusübungen
Improvationen, SIPARI, Jungblut & Aldridge, 2004). Similar to MIT, the MMIT programme is also based on repetition of phrases set to musical structures. However, the
phrases in MMIT are more melodic in structure and less like the “sprechgesang” style
of intonation adopted in MIT (Baker, 2000). A rather new therapy programme in
which music performs a major role is Speech-Music Therapy for Aphasia (SMTA; de
Bruijn, Zielman, & Hurkmans, 2005). SMTA is a treatment programme with a combination of speech language pathology and music therapy. SMTA has components
similar to MIT; however, the most important difference is the expanding of musical
elements like dynamics, tempo, and metre.
Therapy interventions using musical elements to remediate language and speech
abilities have been developed from clinical practice, including SMTA. During the past
10 years positive outcomes have been experienced by patients with neurological communication deficits; however, evidence of the effectiveness of treatment based on the
components of music remains unknown. Therefore a systematic review of literature
1 We refer to the appendix for a definition of music therapy and a more concrete discussion of the various
parameters.
MUSIC IN NEUROLOGICAL SPEECH DISORDERS
3
was needed. The purpose of the study in question is a general review and meaningful
before studying the effect of SMTA in future research.
This article reviews the existing literature on the effect of music in the treatment of
patients with neurological language and speech disorders. Studies were considered for
this review if published in a peer-reviewed journal prior to 2009. In addition, mechanisms of recovery explaining positive effects of the use of music in the treatment of
patients with neurological language and speech disorders were evaluated.
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METHOD
A list of search terms was set-up in order to systematically search in the literature: <language disorders>, <speech disorders>, <communication disorders>,
<aphasia>, <articulation disorders>, <apraxia>, <speech>, <language>,
<verbal>, <oral>, <communication>, <motor speech disorder> and <music>.
These terms were linked using the combinations of: (1) <language disorders> or
<speech disorders> or <communication disorders> or <aphasia> or <articulation
disorders>, (2) <apraxia> and (<speech> or <language> or <verbal> or <oral>
or <communication> or <motor speech disorder>), (3) <music> and (#1 or #2).
We searched in the following databases: PubMed, CINAHL, PsycINFO, and
EMBASE. Reference manager was used to remove duplicates. Subsequently, inclusion criteria were formulated to judge whether an article contributes to the research
questions: (1) effect controlled by measurements before and after intervention,
(2) musical elements as a form of therapy of language and speech disorders caused
by non-congenital neurological disorders (e.g., CVA and TBI), (3) adults, (4) any of
the linguistic modalities, (5) language restrictions: only English, French, German,
and Dutch articles were reviewed. Music was defined as follows: one or more
of the following musical elements: rhythm, melody, accent, practised in vocal or
instrumental form. Language and speech disorders were defined as follows: disorders
of production as well as disorders in reception in all linguistic modalities (speech,
reading, writing, and auditory language comprehension). Particular exclusion criteria
were also delineated: amusia, language acquisition disorders, stuttering, psychiatric
diseases, dementia, hearing disorders (including word deafness), voice disorders,
healthy participants (including professional musicians), epilepsy, and autism.
Two authors (JH and MB) reviewed the abstracts of the selected articles independently of each other. Various articles needed to be read more extensively because it was
unclear from the abstract if they met the inclusion criteria. Both selections were then
compared. When in doubt, the two reviewers consulted with a third reviewer (HR).
A list of variables was compiled in order to describe the articles. A short pilot study
was needed to help determine this list. JH and MB independently assigned the variable values by reading two selected articles. Upon completion of this pilot by group
discussion, the list of variables was established. As a result of the completed list, the
description of articles contains the following three variables: (1) patient characteristics: age, gender, education, dominance, aetiology, speech-language diagnosis, time
post onset, severity of the speech- language impairment, and musical background,
(2) intervention and outcome variables: objective of the treatment, level of outcome
measurements in terms of international classification of functioning (ICF), treatment
programme/method (including condition, schedule, linguistic level, musical parameters) and other language, speech and music therapy interventions, (3) methodological
quality: study design, blinding, sampling, group/participant comparability, treatment
4
HURKMANS ET AL.
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fidelity, outcomes, significance, precision, and intent-to-treat. These quality indicators
originate from the guidelines of the ASHA levels-of-evidence scheme. A study received
1 point for each quality indicator if the highest level of quality was incorporated. In the
cases of indicators with multiple possible levels, only the highest level of quality got
credit. Table 1 outlines the indicators with a description and quality marker.
Variables had to be reported in more than 50% of the articles in order to be included
in the results of this review. When information on a variable was missing in > 50% of
the articles, the variable was excluded from the analyses because the lack of information would be too large to make firm conclusions. All the information of patient
characteristics, intervention and outcome variables, and methodological quality is
based on information provided by the authors of the articles. Any lack of information
is also indicated as not reported.
RESULTS
The combination of search terms yielded 1250 articles. However, 94% of the articles
were excluded since they concerned no therapy study and/or other participant group
than patients with language and speech disorders caused by neurological disorders.
A total of 50 articles were close to being included but were dropped because no effect
controlled by measurements before and after intervention was included in the study.
Two authors (JH and MB) identified a total of 18 articles that met initial inclusion
criteria, with agreement in most of the cases. During the selection of the articles three
were rejected upon review of the full text and after consultation with a third reviewer
(HR). Thus 15 studies were used in the review. The results of 583 patients are described
below of which 82% were depicted in the study of Popovici (1995).
Patient characteristics
Table 2 provides an overview of the 15 studies and corresponding patient characteristics. Three variables were not reported 50% of the time, not meeting the 50% criteria.
These included education, dominance, and musical background. Thus these variables
were excluded from this review. Various ages, from 18 years onwards, were represented
in the studies through an adequate spreading, meaning that all age groups were equally
divided. Four articles did not report any gender information. In the other studies both
sexes were represented in group studies and case series. Notable from Popovici’s study
(1995) is the high percentage of males: 77%. It has not been reported whether this
had any influence on the result of the study. In all (but one) studies, stroke was the
cause of speech disorder of the treated patients (in five studies in combination with
other medical diagnoses). The exception was the study of Baker (2000) who described
two patients with traumatic brain injury (TBI). In nine studies the location of the
lesion was reported; these patients suffered from a left hemisphere stroke. The speechlanguage diagnosis was non-fluent aphasia (Broca’s aphasia or global aphasia) in
13 studies, with an accompanying apraxia of speech in 2 studies. In two articles (Cohen
& Masse, 1993; Tamplin, 2008) patients with dysarthria were also investigated. Most
patients were treated in the chronic phase of recovery, more than 1 year post onset, for
severe language and speech disorders (not explicitly defined).
The practice of keeping investigators or participants
ignorant of the group to which participants are
assigned. For the purposes of the critical appraisal,
blinding refers to assessors only
The method(s) used to choose and assign participants to
the experimental conditions in the study
Blinding
The procedure used to ensure that the treatment was
delivered as intended
The measure(s) used in the study to quantify
improvement
The likelihood that the study findings occurred by chance
The size or magnitude of any difference found between
the treatment under investigation and the control
condition
Participants are analysed according to the group to which
they are initially assigned, regardless of whether or not
they dropped out, fully complied with the treatment, or
crossed over and received the other treatment
Treatment fidelity
Significance
Precision
Intention-to-treat (controlled trials only)
Outcomes
How similar the participants/groups were at the start of
the study or how adequately they were described
Group/participant comparability
Sampling
The type of design used in the study
Description
Study design
Indicator
Quality marker
Random sample adequately described = 1
Random sample inadequately described = 0
Convenience sample adequately described = 0
Convenience sample inadequately described or
hand-picked sample or not stated = 0
Groups/participants comparable at baseline on
important factors (between-participant design) or
participant(s) adequately described = 1
Groups/participants not comparable at baseline or
comparability not reported or participant(s) not
adequately described = 0
Evidence of treatment fidelity = 1
No evidence of treatment fidelity = 0
At least one primary outcome measure is valid and
reliable = 1
Validity unknown but appears reasonable; measure is
reliable= 0
Invalid and/or unreliable = 0
P value reported or calculable = 1
P value neither reported nor calculable = 0
Effect size and confidence interval reported or
calculable = 1
Effect size or confidence interval, but not both, reported
or calculable = 0
Neither effect size nor confidence interval reported or
calculable = 0
Analysed by intention-to-treat = 1
Not analysed by intention-to-treat = 0
Controlled trial = 1
Retrospective case control = 1
Single participant study = 1
Case series = 0
Case study = 0
Assessors blinded = 1
Assessors not blinded or not stated = 0
TABLE 1
Quality indicators in the ASHA levels-of-evidence scheme (2001)
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MUSIC IN NEUROLOGICAL SPEECH DISORDERS
5
49–76
57
57–84
7
8
32
1
15
1
7
Buttet & Aubert, 1980
Cohen, 1992
Cohen & Masse, 1993
Goldfarb & Bader, 1979
Jungblut &
Aldridge, 2004
Jungblut et al., 2006
Kim & Tomaino, 2008
17–82
480
2
8
4
1
Schlaug et al., 2008
Sparks et al., 1974
Tamplin, 2008
Wilson et al., 2006
2m
nr
3 f and 1 f
m
77% m and
23% f
nr
m
2 m and 5 f
8 m and 7 f
m
nr
5 f and 3 m
2 f and 5 m
nr
1 f and 1 m
Gender
CVA left
CVA left
CVA and TBI
CVA left
CVA, tumour, TBI
CVA and TBI
CVA left
Single and multiple
CVAs left
Multiple CVAs left
frontal
CVA left
TBI and CVA left and
right
PD, MS, CVA and CP
CVA left unilateral
CVA left unilateral
TBI
Aetiology
Broca aphasia and
global aphasia
Global aphasia
Nonfluent aphasia,
AoS and
dysarthria
Broca aphasia and
global aphasia
Broca, Wernicke,
and amnestic
aphasia
Broca aphasia
Nonfluent aphasia
Dysarthria
Broca aphasia
Global aphasia
Nonfluent aphasia
and AoS
2 Broca aphasia and
5 global aphasia
Nonfluent aphasia
and dysarthria
Broca aphasia, AoS
and dysarthria
Dysarthria
Speech-language
diagnosis
Severe
Severe
Mild–severe
Severe
Mild, moderate
and severe
nr
12 and 13 months
> 6 months
2.5–9.5 months
46 months
Severe
Severe
Mild, moderate
and severe
Severe
Moderate and
severe
Severe
nr
nr
Severe
Severe
0–51 months
37 months
9 months –
21 years
4–26 years
10 years
nr
1 week –
11 months
nr
4–41 months
9 and 3 months
Time post onset
Severity
speech-language
impairment
m = male, f = female, nr = not reported, TBI = traumatic brain injury, CVA = cerebrovascular accident, PD = Parkinson’s disease, MS = multiple sclerosis, CP = cerebral palsy,
AoS = apraxia of speech.
47 and 58
nr
19-51
52
24–62
8
Naeser & HelmEstabrooks, 1985
Popovici, 1995
50
26–76+
nr
25-74
40-58
7
Belin et al., 1996
32 and 30
2
Number
Baker, 2000
Study
Age
(years)
TABLE 2
Patient characteristics
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6
HURKMANS ET AL.
MUSIC IN NEUROLOGICAL SPEECH DISORDERS
7
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Interventions
Table 3 is a summary of information for therapeutic interventions relative to the
15 studies. One variable did not meet the 50% criterion of reporting: other language,
speech, and music therapy interventions. This variable was therefore not reported in
this overview.
Nine studies evaluated the effectiveness of MIT (Albert et al., 1973). MIT was
therefore the most studied treatment programme. Individual treatment (speechlanguage therapy as well as music therapy) was the most studied treatment condition:
in 12 studies patients received individual treatment. Combinations of SLT and music
therapy have not been reported. The schedules of the treatment intervention varied.
MIT prescribes an intensive schedule of twice a day, 30 minutes each, five times a week.
However, this guideline was not always followed in the studies evaluating the effectiveness of MIT; generally less therapy than recommended was given. All objectives have
been formulated at the impairment level. At this level, sentences were studied the most
at the linguistic levels, and melody and rhythm were the most frequently used musical
parameters.
Methodological quality
An overview of the quality indicators for all 15 studies is presented in Table 4. There
was high agreement between JH and MB in classifying each article. The methodological quality of the studies varied with scores ranges from 0–4 (on a scale of
0–9). Five studies obtained a score of 0, and two studies obtained a score of 4. The
scores of the other studies were in this range. The most frequently used study design
(N = 9) was case series. None of the studies involved a randomised controlled trial
(RCT), and mention of blinding, the use of intention-to-treat, and precision is not
reported. In eight studies information on validity and reliability of the outcome measures was missing. All studies used multiple outcome measures without classification
of main study parameters. Five studies used comprehensive language tests as outcome measure like the Boston Diagnostic Aphasia Examination (BDAE; Goodglass
& Kaplan, 1972) and the Aachener Aphasia Test (AAT; Huber, Poeck, & Williams,
1984). No distinction has been reported in related (speech parameters) and unrelated
measures (non-speech parameters like reading, writing, and auditory comprehension).
In eight studies no p-values were reported.
Effectiveness of intervention
An overview of the effectiveness of interventions of the 15 studies is summarised in
Table 5. All studies reported positive results. It is difficult to define the exact number of
patients that improved because the depiction of the results varied extensively. Detailed
information on which patients improved at which outcome measures was lacking in
most studies evaluating more than one patient (group studies and case series). It is difficult to state the effectiveness of the intervention because all studies included multiple
outcome measures without defining the primary study outcome measure. Cohen and
Masse (1993), for instance, reported improvement at verbal intelligibility but none at
speech rate.
Effectiveness MIT
Effectiveness
SIPARI
Effectiveness
SIPARI
Treatment protocol
with working
guidelines
Goldfarb & Bader,
1979
Jungblut & Aldridge,
2004
Jungblut et al., 2006
Kim & Tomaino,
2008
SIPARI
Musically assisted
speech techniques
1
SIPARI
MIT
Singing group and
rhythm group
Group singing
MIT
MIT
MMIT
Treatment
programme
1
1
1
1
1
Effect of music on
speech
Effect of rhythm and
singing on speech
1
1
1
ICF
Effectiveness MIT
Similarities and
differences
between MIT and
MMIT
Mechanisms of
recovery
Objective
Cohen & Masse,
1993
Buttet & Aubert,
1980
Cohen, 1992
Belin et al., 1996
Baker, 2000
Study
ind (MT)
ind (MT) and group
ind (MT) and group
ind (SLT)
group
group
ind (SLT)
ind (SLT)
ind (MT)
Condition
Schedule
2x pw, 1 hour,
12 weeks + home
training
1x pw, 1 hour group,
10 wk and 2x pw,
1 hour
ind+group + home
training
48 wk, 1x pw, 45 min
ind and 52 wk, 2x
p ind+group
2–3x pw, 30 min,
4 weeks
2x pw, 30 min,
9 weeks
1–108 months,
frequency and
session time, nr
4–10 pw, 20 min,
2–8 months
3x pw, 30 min,
3 weeks
3–4x pw, 1 hour,
5–23 months
TABLE 3
Intervention and outcome variables
Familiar songs,
melody and
rhythm
Familiar songs,
rhythm and
dynamics
nr
Phonemes and
sentences
Familiar songs,
melody and
rhythm
Familiar songs,
melody and
rhythm
Familiar songs,
melody and
rhythm
Melody and rhythm
Melody and rhythm
nr
Sentences
Phonemes, words,
sentences and text
Text
Sentences
Melody and rhythm
Sentences
Musical parameters
Familiar songs,
melody and
rhythm
Linguistic level
Words and sentences
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8
HURKMANS ET AL.
1
Effectiveness MIT
Effectiveness MIT
Effectiveness MIT
Effect of singing on
speech
Effectiveness MIT
Schlaug et al., 2008
Sparks et al., 1974
Tamplin, 2008
Wilson et al., 2006
MIT
MIT
vocal exercises and
singing
MIT and semantic
training
MIT and SRT
MIT
ind (MT)
ind (SLT) and group
ind (MT)
ind (SLT)
ind (SLT)
ind (SLT)
2x pw, 1 hour,
4 weeks + home
training
5x pw, 1,5 hours,
75 sessions
total + home
training
nr
3x pw, 30 min,
8 weeks
nr
nr
Sentences
Melody and rhythm
Melody, tempo,
rhythm and
familiar songs
Melody and rhythm
Melody and rhythm
Sentences
Sentences
Phonemes and text
Melody and rhythm
Melody and rhythm
nr
Sentences
MIT = melodic intonation therapy, MMT = modified melodic intonation therapy, SIPARI = Singen Intonation Prosodie Atmung Rhytmusübungen Improvisationen, ICF,
1 = body function/impairment, SRT = speech repetition therapy, ind = individual, group = group therapy, MT = music therapy, SLT = speech language therapy, nr = not
reported.
1
1
1
1
1
Mechanisms of
recovery
Naeser &
Helm-Estabrooks,
1985
Popovici, 1995
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MUSIC IN NEUROLOGICAL SPEECH DISORDERS
9
nr
nr
na
nr
na
nr
nr
nr
nr
nr
nr
na
Case series
Group study
Case study
Group study
Case study
Case series
Case series
Group study
Case series
Case series
Case series
Case study
nr = not reported, na = not applicable.
nr
nr
nr
Case series
Case series
Case series
Baker, 2000
Belin et al., 1996
Buttet & Aubert,
1980
Cohen, 1992
Cohen & Masse,
1993
Goldfarb &
Bader, 1979
Jungblut &
Aldridge, 2004
Jungblut et al.,
2006
Kim & Tomaino,
2008
Naeser & HelmEstabrooks,
1985
Popovici, 1995
Schlaug et al.,
2008
Sparks et al.,
1974
Tamplin, 2008
Wilson et al.,
2006
Blinding
Study design
Study
no
no
no
no
yes
no
no
no
no
no
no
yes
no
no
no
Sampling
no
yes
yes
yes
yes
no
no
yes
yes
no
no
yes
no
yes
no
Group/participant
comparability
TABLE 4
Methodological quality
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
Treatment
fidelity
yes
no
yes
no
yes
yes
no
yes
yes
no
no
no
no
yes
no
Outcomes
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yes
yes
yes
yes
no
nr
no
no
yes
no
no
yes
no
yes
no
Significance
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
nr
Precision
nr
na
nr
nr
nr
nr
nr
na
nr
na
nr
nr
na
nr
nr
Intention
to treat
10
HURKMANS ET AL.
Number of words
BDAE, MRI, and PET
Articulation, repetition, and
auditory comprehension
6 aspects of voice and
articulation
Speech rate and verbal
intelligibility
Repeating sentences
(3 conditions: normal,
intoned, and intoned with
tapping
Belin et al., 1996
Buttet & Aubert, 1980
Cohen, 1992
Cohen & Masse, 1993
Goldfarb & Bader, 1979
Outcome measure(s)
Baker, 2000
Study
32
1
1
8
7
7
2
N
1
1
1
1
1
ICF
4/7 good improvement,
2/7 mild improvement,
1/7 no improvement
Improvement in speaking
fundamental frequency
variability, speech rate,
and verbal intelligibility
Singing group: improvement
at verbal intelligibility, no
improvement at speech
rate. Rhythm group: no
improvement
Improvement in all
conditions
Number of words increased
in both patients
Improvement at item 2, 4, 5,
13, 14, 15, and 19 of the
BDAE
Measured improvement
TABLE 5
Results
nr
0
4
(Continued)
nr
0
nr
Simple passive (word
hearing) and active (word
repetition) verbal tasks
performed without MIT
results in abnormal
activities of right
hemisphere structures.
Word repetition
performed with MIT
loaded words reactivates
Broca’s area and the
adjacent left prefrontal
cortex
nr
3
0
nr
Mechanisms of recovery
0
Methodological quality
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MUSIC IN NEUROLOGICAL SPEECH DISORDERS
11
AAT
AAT
Articulation, fluency,
prosody and breath
support
BDAE and CT scan
Auditory comprehension,
repetition and naming
Jungblut et al., 2006
Kim & Tomaino, 2008
Naeser & Helm-Estabrooks,
1985
Popovici, 1995
Outcome measure(s)
Jungblut & Aldridge, 2004
Study
1
480
8
7
1
1
1
15
N
1
1
ICF
Wernicke > Broca and
anomic aphasia and MIT
> semantics
Improvement in articulation
and prosody of
spontaneous speech and in
REP and NAM
Improvement in all parts of
spontaneous speech, TT,
REP, and NAM
At all outcome criteria
variable improvement have
been measured at all
7 parts of the protocol
4/8 improvement at the
BDAE
Measured improvement
TABLE 5
(Continued)
nr
0
3
Mechanisms of recovery
Patients who respond
positively to MIT have not
only severe nonfluent
aphasia with slow, poorly
articulated speech and
relatively good auditory
comprehension, but also
the lesions involve Broca’s
area, no large lesion in
Wernicke’s area and no
lesion in the right
hemisphere
nr
nr
2
1
nr
4
Methodological quality
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12
HURKMANS ET AL.
BDAE, repetition and
unison speech
SIT, PDT, ROS, IWPM and
CER
Phrase length
Sparks et al., 1974
Wilson et al., 2006
1
1
1
1
1
4
8
2
Improvement in SIT, PDT,
IWPM, and CER
No improvement in ROS
Improvement in phrase
length
Improvement in 6/8 patients
Improvement in all outcome
measures
2
nr
nr
3
2
Functional imaging tasks
targeting musical
components tend to elicit
greater activity in right
hemispheric brain regions
than in left hemispheric
regions. Tapping the left
hand engages a right
hemispheric sensorimotor
network that coordinates
orofacial articulatory
movements
nr
3
BDAE = Boston Diagnostic Aphasia Examination, MRI = magnetic resonance imaging, PET = positron emission tomography, AAT = Aachen Aphasia Test, CT = computed
tomography, CIU = correct information units, fMRI = functional magnetic resonance imaging, SIT = Sentence Intelligibility Test, PDT = Picture Description Task,
ROS = rate of speech, IWPM = intelligible words per minute, CER = communication efficiency ratios, ICF, 1 = body function/impairment, REP = repeating, NAM = naming,
TT = Token Test, nr = not reported.
Tamplin, 2008
CIU, number of syllables,
picture naming and fMRI
Schlaug et al., 2008
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MUSIC IN NEUROLOGICAL SPEECH DISORDERS
13
14
HURKMANS ET AL.
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Mechanisms of recovery
In three studies (Belin et al., 1996; Naesser & Helm-Estabrooks, 1985; Schlaug,
Marchina, & Norton, 2008) examinations of mechanisms of recovery by PET, CT,
and fMRI were conducted in the method of the study to explain the research findings.
Neural correlates focused mainly on the observed brain activities in both hemispheres
during language tasks and at the location of the lesion. The other 12 studies interpret
their research findings but are hypothetical, since mechanisms of recovery are absent
from the method of the study and therefore not objectively identical.
Schlaug et al. (2008) described two patients: one patient received MIT and the
other patient received a combination of MIT and a control treatment (SRT: speech
repetition therapy). The patient receiving only MIT showed significantly more fMRI
activities in the right hemisphere. Naeser and Helm-Estabrooks (1985) studied two
groups of patients receiving MIT: a good response group and a poor response group
of MIT. CT information characteristics of both groups have been examined. The
good response group showed lesions in Broca’s area in the left hemisphere. The poor
response group showed lesions in both hemispheres and/or Wernicke’s area. Belin
et al. (1996) evaluated a group of seven non-fluent aphasic patients who successfully
finished MIT intervention. They measured changes in relative cerebral blood flow with
PET during listening and repetition of words and during repetition of MIT loaded
words (i.e., with melody and rhythm). Their findings revealed abnormal activation
in the right hemisphere without MIT language task and, in contrast, reactivation in
Broca’s area and the left prefrontal cortex by repeating MIT loaded words.
As a concluding remark of the results, we gathered extensive information about
music and language in the literature. Treatment approaches using musical elements
reported measurable improvement. However, the methodological quality of the efficacy studies was low and mechanisms of recovery were contradictory.
DISCUSSION
The purpose of this study was to review the existing literature on the effect of treatment
using musical elements in the treatment of patients with neurological language and
speech disorders and mechanisms of recovery explaining positive effects. This review
shows that a certain amount of information is revealed in the literature concerning
therapies using musical elements in the treatment of neurological language and speech
disorders. In the reviewed studies frequent gaps in the descriptions of patient characteristics and therapy interventions have been determined. Overall, the methodological
quality of the studies was rated as low.
All but one of the studies involved stroke patients. This is understandable because
stroke patients are a rather homogeneous group in comparison to other patients
with acquired brain injuries (ABI). Findings in these studies can also theoretically be
applied to patients with other types of ABI; however, studies on this subject still need
to be done. Both males and females were included in the investigations under study.
In Popovici (1995) men dominated the study population. This may be explained by a
large subgroup of patients with TBI in their study sample (Tagliaferri, Compagnone,
Korsic, Servadei, & Kraus, 2006). However, selection bias cannot be ruled out.
The studies included patients who were primarily in the chronic phase of post onset
recovery. However, therapy is also given in the subacute phase. It is therefore important
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MUSIC IN NEUROLOGICAL SPEECH DISORDERS
15
in future research to study the effect of music elements in treatment in the subacute
phase.
Education was not reported in the description of patient characteristics in one
third of the reviewed studies. Education may influence learning and is therefore an
important aspect in studying the effectiveness of treatment. Next to education, cognitive functioning is an important predictor of outcome since non-linguistic cognitive
impairments may limit rehabilitation efficacy in patients with aphasia (Seniów, Litwin,
& Leśniak, 2009). We will therefore study cognitive functioning next to education in
future efficacy research. Dominance was also not reported in more than half of the
reviewed studies. Mainly in studies where music is a central topic of research interest,
information about dominance is valuable since mechanisms of recovery focuses on
brain activities in one of the two hemispheres. Information about musical background
was also lacking in patient characteristics (not specifically defined by objective criteria); theoretically, we assume that this variable may influence treatment outcome. The
discrepancy is substantial between the description of language and speech functioning
when information about the musical background is missing. This is especially the case
when studying an intervention in which music plays such an important role. Notable
is that musical elements of therapy mainly comprised melody and rhythm. The fact
that MIT is the most studied programme to date may be an explanation; melody and
rhythm are distinguished features of MIT. Other musical parameters like dynamics,
tempo, and metre have not been applied.
In general, therapy interventions have been adequately described. MIT is an internationally well-known programme (Norton, Zipse, Marchina, & Schlaug, 2009).
Deviations with respect of content as well as therapy intensity of the original
method have been well described. Only a few times have other therapy interventions than the studied intervention (e.g., MIT) been reported. In clinical practice
aphasic patients receive various intervention programmes. It is therefore important
to know if the revealed improvement can be assigned to the studied programme or to
co-interventions.
All the objectives of the reviewed studies were aimed at the (ICF) level of impairments. None of the studies conducted outcome measures at the (ICF) level of activities
and/or participation. Therefore it is unknown whether revealed improvement at the
level of impairments can be generalised in their application to communication in daily
life and if it has any social implications.
The power of evidence was low for the majority of the reviewed studies. A randomised controlled trial (RCT) with an adequate size is hardly accomplishable from a
practical as well as a methodological standpoint (e.g., realising a homogeneous group).
For that reason adequate alternative study designs are available: single-participant
designs and case series (Howard, 2003). These study designs have frequently been used
in the reviewed studies. Case studies and case series offer an extraordinary opportunity
to describe patient characteristics and intervention programmes in detail. The effectiveness of the therapy can be verified very precisely, even in a small group. Not only
is a well-described method important to measure effectiveness of therapy but also the
use of statistics is needed to calculate p-values and to determine the likelihood that
study findings are results of chance. It is here that results of many articles were limited: all studies report improvement but in over half the studies no statistics were used.
That makes it difficult to conclude whether the measured improvement is the result of
the studied therapy programme. For example, although a sufficient number of patients
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16
HURKMANS ET AL.
are included in the study of Popovici (1995), the low level of evidence (score 3) make
their conclusions about the positive effect of the treatment doubtful.
MIT is the therapy programme that was used in the three studies that identify neural correlates to explain mechanisms of recovery. The purpose of MIT is to exploit the
prosodic and melodic process components of the intact right hemisphere for use with
left hemisphere brain-damaged aphasic patients. The authors of the MIT hypothesised
that successful recovery engages expressive language areas in the undamaged right
hemisphere. This hypothesis is over 30 years old. Brain plasticity is profound, and reorganisation processes are dynamic with recovery of language function incorporating
both hemispheres (e.g., Saur et al., 2006). However, this premise of the original developers of MIT is still appropriate, as there has been no research to date that disproves
this hypothesis. Two out of three studies in this review (Naeser & Helm-Estabrooks,
1985; Schlaug et al., 2008) support the hypothesis of Albert et al. (1973). The findings of Belin et al. (1996) were surprising and contrary to the hypothesis proposed by
the developers of MIT and the original interpretation of MIT successes. Belin et al.
reported that the recovery process coincides with the reactivation of left prefrontal
structures with melody and rhythm tasks rather than mechanisms of compensation in
right hemisphere structures.
This review shows the difficulty of proving the effectiveness of therapy using musical
elements. Research in this field is in a fairly early state and an adequate system to classify and describe complex interventions is lacking. We highly recommend the development of research guidelines to standardise data-reporting parameters such as patient’s
characteristics, intervention, and methodological quality. Different models can be
used relevant to rehabilitation. Wade (2005) suggests a method for describing rehabilitation interventions derived from two models: (1) the World Health Organisation’s
International Classification of Functioning model of illness and (2) a model describing
rehabilitation interventions. Patient characteristics can be adequately reported in the
ICF model. Intervention and outcome variables can be adequately reported in Wade’s
model where interventions may be described in terms of the situations where these
actions are applied, the immediate goals of any action, the level at which the intervention acts, the actions involved, the knowledge and skills needed to give the treatment,
any specific equipment used, and any concomitant actions that may be necessary. For
methodological quality, we recommend study designs using the highest level of quality
indicators in the guidelines of ASHA levels-of-evidence scheme.
CONCLUSION
The purpose of this review was to assess the effects of musical elements in the treatment of neurological language and speech disorders. A systematic search of the
literature yielded 15 studies that met inclusion criteria.
Measurable improvement was reported in studies where musical components were
used in the treatment of neurological language and speech disorders. However, the
methodological quality of studies was rated low. Therefore no conclusions can yet be
drawn with regard to the effect of the use of musical elements in the treatment of individuals with acquired neurological disorders. Mechanisms of recovery remain unclear:
two of the three studies that examined mechanisms of recovery via neuroimaging
techniques supported the role of the right hemisphere, but reports are contradictory
MUSIC IN NEUROLOGICAL SPEECH DISORDERS
17
and exact mechanisms of recovery remain indefinable. Shortcomings in the current
research can be overcome by following standards as outlined by the discussion section
in this article.
Manuscript received 26 January 2011
Manuscript accepted 28 June 2011
First published online 6 October 2011
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APPENDIX
Music therapy (MT) can serve different goals in the rehabilitation of neurologically
impaired patients. A common approach in MT is to apply non-verbal aspects dealing with emotional and social problems. In addition, MT can be aimed at verbal
expression and communication. Adults suffering from neurological impairments are
challenged to “relearn” activities of daily living that were once performed with ease, as
well as to emotionally adjust to their limitations and changed life circumstances. These
deep emotions can negatively influence rehabilitation (Baker & Wigram 2004; Jochims
1995; Magee & Davidson, 2002). Throughout the rehabilitation process clients tend
to form a new identity and re-shape their future, which demands significant effort
and perseverance. This process often leads to sadness, anger, and feelings of inferiority and insecurity. MT considers the body and mind as inseparable and therefore
MT approaches focus on the medical-physical and on the social-emotional aspects
of rehabilitation. SMTA, for example focuses primarily on speech-language exercises
set to music; however it also draws on music’s potential for relaxation and enjoyment
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MUSIC IN NEUROLOGICAL SPEECH DISORDERS
19
so clients experience the program as being “less technical”. Patients enjoy the intervention and are able to sustain their participation for long periods of time (Magee,
Brumfitt, Freeman, & Davidson, 2006). The joint singing of patient and therapists
emphasises the social aspect of music making, thereby acting to reduce isolation.
The MT interventions are designed to musically support the speech-language exercises, and as such they share the same structural linguistic levels. Using tempo, metre,
rhythm, and dynamic parameters the music therapist varies the melodies, thereby
increasing the level of difficulty over the course of treatment. The different parameters are adapted to the individual patient’s capabilities, thereby simplifying the singing
exercise for the client when needed (De Bruijn et al., 2005). MT considers music tempo
to be the key for melodic adaptation. Some features of tempo are familiar in MT.
A slow tempo for example creates a sense of relaxation. But a tempo that is too slow
becomes static: there is no flowing motion. This does not stimulate the client and
may negatively affect the patient’s singing. And finally, a fast/faster tempo may stimulate the client and increase the level of concentration required to perform the task.
Variations in metre provide opportunities for the patient to practice the same material
while maintaining interest. Some familiar features of metre are the following: 4/4 and
2/4 beats are supportive, familiar, and easy to sing; 3/4 and 3/8 beats evoke a swaying motion and are suitable when relaxation (decrease in tension) would enhance the
client’s performance in the exercises; and finally a 6/8 beat may be perceived as both
double and triple time. The movement stimulated by the 6/8 beat is relaxing, but may
lead to an increase in tempo. Variations in rhythm are determined by the prosodic features of speech. Some characteristics of rhythm are important in MT: the order of long
and short note values influence the degree of rhythmic complexity and therefore the
exercise’s level of difficulty. For example, in 4/4 time the sequence long–short–short is
more difficult than short–short–long because it allows the patient less time to prepare
himself for the repetition of the exercise. Syncopation is not part of natural speech and
should therefore be avoided in MT.
In MT dynamics ranges from mezzo-piano to mezzo-forte, which is usually the least
taxing on the voice. However, this choice is dependent on the (emotional) content of
the exercise. Some following features related to dynamics should be considered in MT:
crescendos are useful during the repetition of sentences that are intended as exclamations; sometimes the use of forte or even fortissimo is necessary, for example to call or
warn someone or to express emotions.