Melodic Intonation Therapy

Number: 0284

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

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Policy

Scope of Policy

This Clinical Policy Bulletin addresses melodic intonation therapy.

1. Medical Necessity

   Aetna considers melodic intonation therapy medically necessary for members with Broca's aphasia (also known as expressive or non-fluent aphasia) when all of the following selection criteria are met:

   1. Member has good auditory comprehension; and
   2. Member is well-motivated, emotionally stable, and has a good auditory span; and
   3. Member's repetition is poor, even for single words; and
   4. There is no evidence of bilateral brain involvement; and
   5. Verbal production is non-fluent, with diminished articulator agility and effortful initiation of speech production.

2. Experimental, Investigational, or Unproven

   The following procedures / indications are considered experimental, investigational, or unproven because the effectiveness of these approaches or indications has not been established (not an all-inclusive list):

   1. Melodic intonation therapy for:

      1. Dysarthria
      2. Other types of aphasia
      3. Raising trans women's singing and speaking fundamental frequencies
      4. Verbal apraxia; and
      5. For all other indications;

   2. Adjunctive use of transcranial magnetic stimulation / transcranial brain stimulation with melodic intonation therapy for the treatment of aphasia.

3. Policy Limitations and Exclusions 

   Note: Melodic intonation therapy should be administered by a speech pathologist who is trained and qualified to work with individuals with aphasia and is experienced with the melodic intonation therapy techniques. Melodic intonation therapy is best given in short, frequent sessions (30-min sessions) over a short time span (3 to 6 weeks).

4. Related Policies

   • CPB 0469 - Transcranial Magnetic Stimulation and Cranial Electrical Stimulation

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Table:

CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
CPT codes not covered if selection criteria are met:
Melodic intonation therapy- no specific code
90867	Therapeutic repetitive transcranial magnetic stimulation (TMS) treatment; initial, including cortical mapping, motor threshold determination, delivery and management
90868	subsequent delivery and management, per session
90869	subsequent motor threshold re-determination with delivery and management
Other CPT codes related to the CPB:
92507	Treatment of speech, language, voice communication, and/or auditory processing disorder; individual
92508	group, two or more individuals
Other HCPCS codes related to the CPB:
G0153	Services performed by a qualified speech-language pathologist in the home health or hospice setting, each 15 minutes
S9128	Speech therapy, in the home, per diem
ICD-10 codes covered if selection criteria are met:
I69.020 I69.120 I69.220 I69.320 I69.820 I69.920	Sequelae of cerebrovascular disease, aphasia
R47.01	Aphasia
ICD-10 codes not covered for indications listed in the CPB (not all-inclusive):
F64.0 - F64.9	Gender identity disorders
F80.0 - F80.9	Specific developmental disorders of speech and language
R47.1	Dysarthria and anarthria
R48.1 - R48.8	Agnosia, apraxia and other symbolic dysfunctions

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Background

Aphasia refers to a degraded language capability due to lesions in the cortical language areas or association pathways.  Expressive aphasia (also known as non-fluent, anterior, or motor aphasia) affects spoken language (Broca's area) while receptive aphasia (also known as fluent, posterior, or sensory aphasia) affects language interpretation and memory (Wernicke's area).  Total (or global) aphasia is the consequence of large lesion(s) in the perisylvian area, extending deep into the subjacent white matter.  It can involve the frontal, temporal, and parietal lobes, resulting in the loss of all of nearly all speech and language functions.  Transcortical motor aphasia (also called anterior isolation syndrome) is caused by damage in the cortical areas around Broca's area, but sparing the arcuate fasciculus and Wernicke's area while transcortical sensory aphasia (also called posterior isolation syndrome) results from damage in the cortical areas around Wernicke's area, but sparing the arcuate fasciculus and Broca's area.

Melodic intonation therapy (MIT) is a type of speech-language therapy that uses melodic and rhythmic components to purportedly assist in speech recovery for individuals with non-fluent aphasia. During MIT sessions a person with non-fluent aphasia is encouraged to hum, and then to sing words or phrases they find hard to recall, while tapping out a rhythm (NHS, 2011).  Melodic intonation therapy typically consists of speaking with a simplified and exaggerated prosody, characterized by a melodic component (2 notes, high and low) and a rhythmic component (2 durations, long and short).  This technique has been shown to increase the number of words a person can recall.  This may be due to the fact that the part of the brain we use to recall song lyrics and music is different from the part of the brain we use to recall spoken language.  Thus, MIT teaches a person with non-fluent aphasia an alternative way to recall words and phrases.  However, most aphasic patients do not respond to MIT.  This includes those with global and transcortical aphasia and almost all with evidence of significant posterior language area involvement.

There is some evidence that MITis effective for treating the speech-related problems of children and adults when diagnosed with Broca's aphasia (AAN, 1994).  However, the technique is now being used with children diagnosed with developmental apraxia of speech, which is defined as a speech articulation disorder not involving sensory or motor paralysis. 

A systematic review of the evidence by Roper (2003) concluded that "there is little to no evidence available supporting the effectiveness of Melodic Intonation Therapy (MIT) for children with apraxia."  Based on this evidence-review, the Center for Evidence-Based Practices of the Orelena Hawks Puckett Institute (2003) made the following recommendation: "Use of modified forms of melodic intonation therapy to assist the speech development of young children who have apraxia of speech can not be recommended as a beneficial intervention until the practice is studied more carefully and thoroughly."

A Medicare National Coverage Determination (1983) states that MIT is a covered service only for nonfluent aphasic patients unresponsive to conventional therapy, and only when the conditions for coverage of speech pathology services are met.

In a pilot study, Tamplin (2008) examined the effects of vocal exercises and singing on intelligibility and speech naturalness for subjects with acquired dysarthria following traumatic brain injury or stroke.  A multiple case study design was used, involving pre-, mid-, and post-treatment assessments of intelligibility, rate, naturalness, and pause time for 4 subjects with dysarthria.  Each subject participated in 24 individual music therapy sessions over 8 weeks involving oral motor respiratory exercises, rhythmic and melodic articulation exercises, rhythmic speech cuing, vocal intonation therapy, and therapeutic singing using familiar songs.  Results were measured using a standardized dysarthric speech assessment – the Sentence Intelligibility Test, waveform analysis, and ratings of speech naturalness.  Statistically significant improvements in functional speech intelligibility were achieved but improvements in rate of speech were insignificant.  Speech naturalness improved post-treatment and a reduction in the number and length of pauses was verified via waveform analysis.  The author stated that these preliminary findings suggested that a program of vocal exercises and singing may facilitate more normative speech production for people with acquired dysarthria and supported the need for further research in this area.

Chrysikou and Hamilton (2011) stated that aphasia is a common consequence of unilateral stroke, typically involving perisylvian regions of the left hemisphere.  The course of recovery from aphasia after stroke is variable, and relies on the emergence of neuroplastic changes in language networks.  Recent evidence suggested that rehabilitation interventions may facilitate these changes.  Functional re-organization of language networks following left-hemisphere stroke and aphasia has been proposed to involve multiple mechanisms, including intra-hemispheric recruitment of peri-lesional left-hemisphere regions and transcallosal inter-hemispheric interactions between lesioned left-hemisphere language areas and homologous regions in the right hemisphere.  Moreover, it is debated whether inter-hemispheric interactions are beneficial or deleterious to recovering language networks.  Transcranial magnetic stimulation (TMS) and tDCS are non-invasive procedures that can be applied clinically to modulate cortical excitability during post-stroke language recovery.  Intervention with these non-invasive brain stimulation techniques also allows for inferences to be made regarding mechanisms of recovery, including the role of intra-hemispheric and inter-hemispheric interactions.  The authors reviewed recent evidence that suggests that TMS and tDCS are promising tools for facilitating language recovery in aphasic patients.

Lim et al (2013) examined the therapeutic effect of neurologic music therapy (NMT) and speech language therapy (SLT) through improvement of the aphasia quotient (AQ) in post-stroke aphasic patients.  A total of 21 post-stroke, non-fluent aphasia patients who had ischemic/hemorrhagic stroke on radiologic evaluation were divided into the NMT and SLT groups.  They received NMT and SLT for 1 month.  Language function was assessed by Korean version-Western Aphasia Battery before and after therapy.  Neurologic music therapy consisted of therapeutic singing and MIT, and SLT consisted of language-oriented therapy.  Significant improvements were revealed in AQ, repetition, and naming after therapy in the NMT group and improvements in repetition in the SLT group of chronic stroke patients (p < 0.05).  There were significant improvements in language ability in the NMT group of subacute stroke patients.  However, there was no significant improvement in the SLT group of subacute stroke patients.  The authors concluded that the NMT as well as SLT are effective treatments in the chronic stage of stroke; and NMT is effective in subacute post-stroke aphasic patients.

van der Meulen et al (2014) examined if language production treatment with MIT is effective in subacute severe non-fluent aphasia.  A multi-center, randomized controlled trial was conducted in a waiting-list control design: Patients were randomly allocated to the experimental group (MIT) or the control group (control intervention followed by delayed MIT).  In both groups, therapy started at 2 to 3 months post-stroke and was given intensively (5 hrs/wk) during 6 weeks.  In a second therapy period, the control group received 6 weeks of intensive MIT.  The experimental group resumed their regular treatment.  Assessment was done at baseline (T1), after the first intervention period (T2), and after the second intervention period (T3).  Effectiveness was evaluated at T2.  The impact of delaying MIT on therapy outcome was also examined.  A total of 27 participants were included (n = 16 in the experimental group and n = 11 in the control group).  A significant effect in favor of MIT on language repetition was observed for trained items, with mixed results for untrained items.  After MIT there was a significant improvement in verbal communication but not after the control intervention.  Finally, delaying MIT was related to less improvement in the repetition of trained material.  The authors concluded that in patients with subacute severe non-fluent aphasia, language production treatment with MIT was effective; and earlier treatment may lead to greater improvement.

Zumbansen et al (2014) critically reviewed the literature on MIT, one of the most formalized treatments used by speech-language therapist in Broca's aphasia.  These investigators suggested basic clarifications to enhance the scientific support of this promising treatment.  First, therapeutic protocols using singing as a speech facilitation technique are not necessarily MIT.  The goal of MIT is to restore propositional speech.  The rationale is that patients can learn a new way to speak through singing by using language-capable regions of the right cerebral hemisphere.  Eventually, patients are supposed to use this way of speaking permanently but not to sing overtly.  These researchers argued that many treatment programs covered in systematic reviews on MIT's efficacy do not match MIT's therapeutic goal and rationale.  Critically, these researchers identified 2 main variations of MIT:

1. the French thérapie mélodique et rythmée (TMR) that trains patients to use singing overtly as a facilitation technique in case of speech struggle and palliative versions of MIT that help patients with the most severe expressive deficits produce a limited set of useful, ready-made phrases;
2. distinguishing between the immediate effect of singing on speech production and the long-term effect of the entire program on language recovery.

Many results in the MIT literature can be explained by this temporal perspective.  The authors proposed that MIT can be viewed as a treatment of apraxia of speech more than aphasia.  They stated that this issue should be explored in future experimental studies.
Al-Janabi et al (2014) investigated whether or not the right hemisphere can be engaged using MIT and excitatory repetitive TMS (rTMS) to improve language function in people with aphasia.  The 2 participants in this study have chronic non-fluent aphasia.  A functional magnetic resonance imaging (fMRI) task was used to localize the right Broca's homolog area in the inferior frontal gyrus for rTMS coil placement.  The treatment protocol included an rTMS phase, which consisted of 3 treatment sessions that used an excitatory stimulation method known as intermittent theta burst stimulation, and a sham-rTMS phase, which consisted of 3 treatment sessions that used a sham coil.  Each treatment session was followed by 40 mins of MIT.  A linguistic battery was administered after each session.  The results showed that 1 participant improved in verbal fluency and the repetition of phrases when treated with MIT in combination with TMS.  However, the second patient showed no evidence of behavioral benefit from this brief treatment triai.  Post-treatment neural activity changes were observed for both participants in the left Broca's area and right Broca's homolog.  The authors concluded that the findings of these case studies indicated that a combination of MIT and rTMS applied to the right Broca's homolog has the potential to improve speech and language outcomes for at least some people with post-stroke aphasia.

Raising Trans Women's Singing and Speaking Fundamental Frequencies

Loutrari and Georgiadou (2022) noted that voice interventions for transgender individuals could address several speech and voice parameters -- fundamental frequency, resonance, intonation, rhythm, and intensity.  These investigators focused on fundamental voice frequency and built on existing research to test one technique that has been shown in a preliminary study to adjust fundamental voice frequency in line with clients' objective.  More specifically, these researchers used an adaptation of MIT to examine if it could raise trans women's average fundamental frequency to a significant degree.  A total of 11 trans women participated in 2 one-on-one therapy sessions, 4 weeks apart.  Results pointed to a statistically significant rise in both their singing and speaking fundamental frequencies following the adapted MIT therapy sessions.  Subjects were also successful in imitating upward fundamental frequency contours when singing and in producing them independently in the speech modality.  The authors concluded that longitudinal studies are needed to examine if the observed positive results would translate into long-term benefits.

Melodic Intonation Therapy Combined with Transcranial Direct Current Stimulation for the Treatment of Post-Stroke Aphasia

Vines et al (2011) noted that research has suggested that a fronto-temporal network in the right hemisphere may be responsible for mediating MIT’s positive effects on speech recovery.  These researchers investigated the potential for a non-invasive brain stimulation technique, transcranial direct current stimulation (tDCS), to augment the benefits of MIT in patients with non-fluent aphasia by modulating neural activity in the brain during treatment with MIT.  The polarity of the current applied to the scalp determines the effects of tDCS on the underlying tissue: anodal-tDCS increases excitability, whereas cathodal tDCS decreases excitability.  These investigators applied anodal-tDCS to the posterior inferior frontal gyrus of the right hemisphere, an area that has been shown both to contribute to singing through the mapping of sounds to articulatory actions and to serve as a key region in the process of recovery from aphasia, particularly in patients with large left hemisphere lesions.  The stimulation was applied while patients were treated with MIT by a trained therapist.  A total of 6 patients with moderate-to-severe non-fluent aphasia underwent 3 consecutive days of anodal-tDCS + MIT, and an equivalent series of sham-tDCS + MIT.  The 2 treatment series were separated by 1 week, and the order in which the treatments were administered was randomized.  Compared to the effects of sham-tDCS + MIT, anodal-tDCS + MIT led to significant improvements in fluency of speech.  The authors concluded that these results support the hypothesis that, as the brain seeks to re-organize and compensate for damage to left hemisphere language centers, combining anodal-tDCS with MIT may further recovery from post-stroke aphasia by enhancing activity in a right hemisphere sensorimotor network for articulation.  These preliminary findings need to be validated by well-designed studies.

Marangolo (2020) noted that aphasia is a highly disabling language disorder usually caused by a left stroke brain damage.  Even if traditional language therapies have proven to induce an adequate clinical recovery, a large percentage of patients are left with chronic deficits at 6 months post-stroke; thus, new strategies to common speech therapies are needed to maximize the recovery from aphasia.  The author stated that tDCS is a very promising tool as a supplementary treatment to aphasia recovery.

Cichon et al (2021) stated that aphasia is one of the most common clinical features of functional impairment following stroke.  About 21 % to 40 % of stroke patients sustain permanent aphasia, which progressively worsens one's quality of life (QOL) and rehabilitation outcomes.  Post-stroke aphasia treatment strategies include speech language therapies, cognitive neurorehabilitation, tele-rehabilitation, computer-based management, experimental pharmacotherapy, as well as physical medicine.  These investigators examined available evidence of the effectiveness of impairment-based aphasia therapies and communication-based therapies (as well as the timing and optimal treatment intensities for these interventions).  In addition, they presented specific interventions (e.g., constraint-induced aphasia therapy [CIAT] and MIT).  These researchers stated that accumulated data suggested that the use of TMS and tDCS was safe, and could be used to modulate cortical excitability; thus, these investigators reviewed clinical studies that presented TMS and tDCS as (possible) promising therapies in speech and language recovery, stimulating neuroplasticity.  The author noted that a meta-analysis presented by the Cochrane Library, which included 21 randomized clinical trials, showed no evidence of improved functional communication both after tDCS therapy (0.17, 95 % CI: -0.20 to 0.55, p = 0,37), and during follow-up (0.14, 95 % CI: -0.31 to 0.58, p = 0.55).  However, tDCS improved noun-naming after therapy (0.42, 95 % CI: 0.19 to 0.66, p = 0.0005), and during therapy (0.87, 95 % CI: 0.25 to 1.48, p = 0.006); however, it did not improve verb naming.  There were also no adverse effects and no effect of tDCS on cognitive functioning.  Moreover, these researchers noted that the most favorable effects of PSA treatment with tDCS were observed in the chronic phase of the disease.  In order to unequivocally ascertain the effectiveness of the intervention, further randomized clinical trials with larger sample sizes are needed.

Yan et al (2023) noted that more than 10 million new stroke cases occur every year globally, of which aphasia accounts for about 1/3.  Aphasia has become an independent predictor of functional dependence and death for the stroke population.  The closed-loop rehabilitation of combining behavioral therapy with central nerve stimulation appeared to be the research trend of post-stroke aphasia (PSA) due to its advantages in improving linguistic deficits.  In a single-center, assessor-blinded, randomized controlled trial (RCT), these researchers examined the effectiveness of a closed-loop rehabilitation program combining MIT with tDCS for patients with PSA.  They screened 179 patients and included 39 PSA subjects in China; demographic and clinical data were documented.  The primary outcome was the Western Aphasia Battery (WAB) used to examine language function, and the secondary outcomes included Montreal Cognitive Assessment (MoCA), Fugl-Meyer Assessment (FMA), and Barthel Index (BI) for evaluating cognition, motor, and activities of daily living (ADL), respectively.  With the computer-generated randomization sequence, subjects were randomly divided into the conventional group (CG), MIT combined with sham stimulation group (SG), and MIT combined with tDCS group (TG).  After the 3-week intervention, the functional changes in each group were analyzed by the paired sample T-test, and the functional difference between the 3 groups was analyzed by ANOVA.  There was no statistical difference on the baseline.  After the intervention, the WAB's aphasia quotient (WAB-AQ), MoCA, FMA, and BI were statistically different in SG and TG, including all the sub-items in WAB and FMA, while only listening comprehension, FMA, and BI were statistically different in CG.  The differences of WAB-AQ, MoCA, and FMA were statistically different among the 3 groups; however, BI was not.  The post-hoc test results showed that the changes of WAB-AQ and MoCA in TG were more significant than the others.  The authors concluded that MIT combined with tDCS or sham stimulation was effective for patients with PSA; however, the conventional treatment could not significantly improve aphasia in the short-term.  Compared with sham stimulation, the closed-loop rehabilitation scheme combining MIT and tDCS could augment the positive effect on language and cognitive recovery in PSA.  These preliminary findings need to be validated by well-designed studies.

The authors noted that the mean post-stroke duration of TG was approximately 8 months, which was longer than the other 2 groups (CG and SG) in this study; however, the effectiveness of TG was stronger.  These researchers stated that in the future, it is necessary to continue to perform stratified research according to the course of the disease.  Furthermore, due to previous studies focusing on behavioral indicators and insufficient imaging evidence, the neurological effect of MIT on aphasia patients was still unclear.  In this study, there was also a lack of neuroimaging detection, and the potential neural recovery mechanism of closed-loop rehabilitation also needed to be further examined.

Marin-Medina et al (2024) stated that following a stroke, several mechanisms of neural plasticity can be activated, which may result in significant recovery.  Rehabilitation therapies aim to restore surviving tissue over time and re-organize neural connections.  With more patients surviving stroke with varying degrees of neurological impairment, new technologies have emerged as a promising option for better functional outcomes.  These investigators examined restorative therapies based on brain-computer interfaces, robot-assisted and virtual reality, brain stimulation, as well as cell therapies.  Brain-computer interfaces allow for the translation of brain signals into motor patterns.  Robot-assisted and virtual reality therapies provide interactive interfaces that simulate real-life situations and physical support to compensate for lost motor function.  Brain stimulation can modify the electrical activity of neurons in the affected cortex.  Cell therapy may promote regeneration in damaged brain tissue.  These researchers stated that non-invasive brain stimulation (e.g., TMS and tDCS) holds promise as an adjuvant therapy for future research, and possible translational applications in clinical scenarios, especially for post-stroke rehabilitation.

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References