For Parkinson’s Disease, Strike Up the Band

Joel Popkin, MD, MACP

Parkinson’s Disease (PD) is a truly multisystem disorder, involving to a varying degree the central and autonomic nervous systems, the immune system, and gastrointestinal tract. In addition, a number of serious non-motor symptoms are often present, including dementia, psychosis, depression, anxiety, and sleep disturbances, among others. A complex multidisciplinary approach is often required (1).

Exercise is a protective factor for PD (1), and intensification of exercise is an integral part of music therapy (MT) – the topic of this article –although music therapy covers a lot more territory than simply exercise. Music therapy has been defined “as the use of sounds and music within an evolving patient-therapist relationship to support and develop physical, mental, and social spiritual well-being.” (2)

In light of the multifaceted nature of PD, MT programs vary considerably in design and purpose, with emphasis on diverse approaches such as listening, rhythm, rhythmic auditory stimulation (RAS), singing, and other interventions. Importantly, MT plays a powerful and well-documented non-pharmaceutical role in the management of PD. (2)

Exercise therapy alone has been increasingly applied in PD rehabilitation, and it is reported to significantly improve non-motor symptoms such as anxiety, fatigue, and depression, as well as quality of life. Since external cues during exercise further improve gait and motor function in PD, (3) you know where I’m going with this: Music perfectly fulfills the role for external cueing. Its effects are related to timing of auditory stimuli and an activation of pleasure induced by activation of the limbic system and consequent dopamine release (4). This may in part be due to remodeling of fronto-centroparietal/temporal connectivity, which could counter the loss of automatic and rhythmic movements in PD. Cueing that is specifically tailored to individual patients further amplifies the therapy (3).

Because well-designed MT has generally positive effects on the emotion and reward systems, therapy is almost universally enjoyed by the patient. It therefore encourages patients to actively take part in their treatment of PD. Improved balance and mobility are documented for at least the first and second years of music-cued dance training, pointing to long-term beneficial effects (4). Therapy that is so acceptable is particularly important for long-term compliance, since the effects are not maintained if therapy ends, and losses in cognition and muscle strength occur as well (5).

But it is only recently that we have had robust meta-analytic data to confirm the actual effect of MT on a patient’s motor function, balance, gait, mental health, and quality of life. The story is positive for walking velocity, improvement of freezing, and improved mental health, leading to an overall improvement of quality of life (4).

Voice development with a group singing program – another significant part of MT – has led to improvements in memory, language, speech processing, voice, and respiratory muscle strength in the elderly community, and this has also been the case with PD (2). Group singing has been especially beneficial for offsetting the onerous social isolation and poor morale that so often accompanies PD.

This has not been lost in my own community of Shrewsbury, Massachusetts, where The Choral Singing Program for Parkinson’s, directed by David Russell, meets weekly to offer a therapeutic singing program. The commentary from participants is inspiring. (6)

If music therapy, which broadly incorporates listening and processing of music, seems so effective, what about “mental music?” Can simply thinking about music or humming tunes produce similar effects?

A study by Harrison (7) shows that different tempos of internal cueing by singing aloud or thinking about tunes can improve gait and improve motor performance for elderly adults as well as those with PD. Walking trials with internal and external cueing were conducted at 90%, 100%, and 110% of their preferred cadence. High cadence rates seem advantageous, but optimal cueing needs to be determined individually. Participants modified their cadence and stride length and reduced gait variability. But gait variability, a risk factor for falls, was reduced only with internal clueing (7), and traditional external cueing may actually increase variability (8). In a more practical sense regarding internal cueing, when walking down the street, mental singing may be less attention-grabbing than singing out loud. (8)

The anatomical model of what is happening with mental music hasn’t been entirely elucidated, but I have some ideas. About six or seven years ago I stopped by the functional MRI research lab at UMass Chan Medical School and asked if they would consider doing an fMRI music study on me. They kindly set up the three tests I requested:

1. The control – listening to the bylaws of our hospital, read by my wife in the most boring monotone she could muster. The plan was for this to be the fMRI equivalent of being brain dead.

2. Listening to a sonata that I know very well –the Rachmaninoff Cello Sonata – with which for years I struggled mightily with on the piano to accompany my son.

3. Silence – only thinking about playing the Rachmaninoff.

To make any sense of the following fMRIs, we need to recall that the areas of uptake in red and yellow are in comparison to another parameter which is subtracted from the scan. So, if activity is equally increased in both of those parameters, we will see gray – which could seem to indicate that nothing is going on, but that’s therefore not necessarily the case. (Don’t fret over this.)

Using a few representative slices of brain, what follows is an “executive summary” of multiple MRI images taken for the three parts of the study.

In Fig 1a, listening to the bylaws and subtracting listening to music, somewhat surprising is my auditory cortex lighting up with the bylaws reading (red outline), but no emoting, as opposed to Fig 1b, in music listening fMRI where we see much emotional activity (yellow outline), but no activity in the auditory cortex. (I was obviously intensely engaged by my wife’s rendition of the bylaws.)

In listening to the bylaws and subtracting thinking about music (Fig 2a), the music is silent, so this time we expect (and see) substantial uptake in the auditory cortex (outlined in red) and an absence of emoting.

In Fig 2b mental music produces no auditory uptake, but leads to striking emoting (outlined in yellow) and brain stem activity (outlined in green). The brain stem (most prominent uptake of which is in the pons) includes pathways exiting the brain to activate motor activities in the body.

In Fig 3a, listening to music, as expected, lights up the auditory cortex (outlined in red), but in Fig 3b with thinking, we see executive decisions flying (outlined in blue), as well as much emoting activity outlined in red. This activity took place in the right basal ganglia, the parietooccipital regions, the cerebellum, and all sorts of non-specific areas, including the visual cortex. The brainstem outlined in green is prominent.

It seems that no matter what the parameter, the pons lights up with mental music. Is my brain directing my fingers to start working, and am I “visualizing” the keyboard and/or the score? This (finally) gets to my question about mental music impacting so dramatically on gait – probably more than external cueing, which in its own right is so impressive. Is this because of activation of the brainstem (corticospinal tract), and would this be an area worth further study?

The medical literature most often leaves the human side of interventions to our imagination, since the hard objectivity of p values is unlikely to activate our brains’ emotional centers. About six years ago I diagnosed my brother-in-law, Gary, with PD. In the last year or so he has struggled. I was unable to find a music therapist in his home country of the Philippines, but my niece found a dance instructor whose enthusiasm and skills are infectious, and he put together a wonderful program on the fly. So, allow me to introduce you – with their permission – to Gary, music/dance therapist Jaypee, and home aide Glenda. By spending eight minutes watching this video, I think you will experience a valuable human side to this story.

In conclusion, MT improves mobility, balance, voice, speech processing, anxiety, fatigue, depression, socialization, and more. Unfortunately, impressive functional gains are not maintained if therapy is discontinued. The hope for our PD patients is that our medical colleagues will more actively write prescriptions for music therapy, importantly coordinated by a skilled music therapist.

Luana Katlen da Silva et al. (5) astutely recommends this take-home message for our patients: “Never stop the music.” I think we should certainly consider this advice. +

References

1. Costa, H.N., Esteves, A.R., Empadinhas, N., et al. Parkinson›s Disease: A Multisystem Disorder. Neurosci. Bull. 39, (2023) 113–124

2. Sotomayor, Manuel Joaquín Machado, ArufeGiráldez, Víctor, et al. Music Therapy and Parkinson’s Disease: A Systematic Review from 2015–2020. Int. J. Environ. Res. Public Health 2021, 18, pp. 01-16.

3. Calabrò, Rocco Salvatore et al. Walking to your right music: a randomized controlled trial on the novel use of treadmill plus music in Parkinson’s disease. Journal of NeuroEngineering and Rehabilitation (2019) 16:68.

4. Zhou, Zonglei, Zhou, Ruzhen et al. Effects of music-based movement therapy on motor function, balance, gait, mental health, and quality of life for patients with Parkinson’s disease: A systematic review and metaanalysis. Clinical Rehabilitation (2021). Vol. 35(7) 937–951.

Joel Popkin, MD, MACP is a Professor of Medicine at UMass Chan Medical School and a Program Director Emeritus at St. Vincent Hospital.

For Parkinson’s Disease, Strike Up the Band Continued

5. Da Silva, Luana Katlen, et al. Music-based physical therapy in Parkinson’s disease: An approach based on international Classification of Functioning, Disability and Health. Journal of Bodywork and Movement Therapies. (2021) Vol 26, pp. 524-529.

6. https://www. apdaparkinson.org/ community/massachusetts/ resources-support-ma/ arts-movement-classes/artmusic/ (Accessed March 28, 2023)

7. Harrison, EC, Horin, AP, Earhart, GM. Mental singing reduces gait variability more than listening to music for healthy older adults and people with Parkinson’s disease. J. Neurol. Phys. Ther. 2019, 43, 204–211.

8. Harrison, EC, Earhart, GM. The effect of auditory cues on gait variability in people with Parkinson’s disease and older adults: a systematic review. Neurodegenerative Disease Management. 2023 Jan 25. (Ahead of Print.)