By Siddhant Patel
Published 11:29 EST, Mon October, 18th, 2021
Introduction
Dementia is a syndrome in which there is a decline in cognitive function, which differs from the natural decline caused by ageing, and has negative impacts on behaviour and emotions.[1] This neurodegenerative syndrome is surreptitiously progressive and may advance into the late stage of dementia. In this stage, the patient is unaware of their surroundings and may have great difficulty in recognizing family and friends, also they may have difficulty in movement, due to an impairment in their motor cortex.
Around 850,000 people are expected to have dementia in the UK, and this number is projected to rise to 2 million by 2050.[2]Globally, there are about 50 million cases; this is projected to rise to 152 million by 2050. Evidently, dementia is one of the greatest medical challenges of our time and is one of the major causes of disability among the elderly. The diseases that cause dementia are complex, but there are some known risk factors: age, genes, medical history and lifestyle. The most influential risk factor to a great extent is age, however, dementia is certainly not an inevitable aspect of ageing. Through changes to our lifestyle, we can reduce about a third of our risk to dementia. For example, changes to improve our cardiovascular health can reduce our risk. In spite of the great risk posed by age, dementia does not by any means exclusively affect the elderly: young onset dementia accounts for 9% of cases worldwide.
There are many different forms of dementia. The most common type is Alzheimer’s disease, accounting for two-thirds of all cases. The presence of ß-amyloid (a protein) plaques and neurofibrillary tangles made up of tau protein are believed to cause Alzheimer’s disease. Other forms include vascular dementia (20%), dementia with Lewy bodies (15%) and frontotemporal dementia (>5%), which is degeneration of the frontal lobe of the brain. These types are not completely distinct from each other and mixed forms exist, which are called mixed dementia.
Currently, there is no pharmacological cure for dementia.[3] However, some drugs may alleviate some symptoms (albeit for a short time) and there are other drugs to mitigate secondary problems caused by dementia such as antidepressants, anxiolytics and sleeping pills. For Alzheimer’s disease, there are four licensed drugs: donepezil, galantamine, rivastigmine and memantine. Donepezil, galantamine and rivastigmine are cholinesterase inhibitors and they slow the breakdown of a neurotransmitter called acetylcholine. Memantine works by blocking the excessive activity of glutamate, which is the most abundant neurotransmitter. Excessive activity of glutamate causes excitotoxicity (neurons are damaged/killed) and cell death, leading to the neurodegeneration experienced in Alzheimer’s disease.[4]
The Brain – Music Perceptibility
Before we can understand how music is perceived, we have to acknowledge the sheer complexity of the brain. Compared to other structures and systems of the human body, the brain is by far the most intricate and complicated feature. Weighing three pounds, the brain is made up of more than 100 billion nerves, which have trillions of connections called synapses.[5]
Evidently, this added layer of uncertainty and the unknown hinders our clinical understanding. Nonetheless, with the help of new technology, scientists and researchers have been able to understand the structural and neural pathways that music undergoes in order for humans to perceive it.
Firstly, the sound waves travel through the ear canal, tympanic membrane and ossicular chain to reach the cochlea, which is in the inner ear. In the cochlea, the acoustic deconstruction takes place in a tonotopic (i.e. frequency dependant) fashion, which triggers afferent potentials. They then travel down the cochlear nerve, to the brainstem and reach the auditory cortical structures in the brain.[6] From then on, the signals get sent to and affect many different areas of the brain.
The temporal lobe is where we process what we hear and appreciate music. Language and words are interpreted in the left hemisphere; music and sound are interpreted in the right hemisphere. However, music does not only affect one area of the brain. The cerebellum coordinates movement and stores physical memory, including muscle memory, such as playing the piano. Neuroscientist Kiminobu Sugaya argues that “memories in the cerebellum never fade out,” suggesting that patients with severe neurodegenerative disease can still carry out some activities which may help to keep them and their brains active. He also suggests that professional musicians might visualize a music score when they are listening to music by using their occipital lobe, which processes what we see. Sugaya refers to music as a very addictive drug which increases dopamine in the nucleus accumbens, similar to illegal drugs such as cocaine. According to world-renowned violinist Ayako Yonetani, music results in increased neurogenesis in the hippocampus, leading to more neuron production and improved memory. She also suggests that music temporarily stops the symptoms in Parkinson’s disease by increasing dopamine levels in the putamen and increasing our response to rhythm.[7] However, these improvements only last until the music stops.
It has been proved that music affects many regions of the brain, unlike other activities. This idiosyncrasy of music is perhaps why many researchers have wanted to discover its therapeutic benefits for many medical conditions, notably dementia.
Music Therapy
Music therapy can be conducted through various interventions. These may be passive (listening to ambient music) or active (singing or playing an instrument).
Many studies have used receptive music for listening to treat some symptoms, including a study conducted in 2003 in New South Wales, Australia.[8] The objective was to determine the effect of background, baroque music on patients with dementia. Baroque music is known for its slow, calm movements and famous baroque music composers include Handel, Vivaldi, Bach, Scarlatti, Telemann and Purcell. In this case, music by Bach, Handel, Vivaldi and Corelli was used. The music pieces were played to a ward of 14 patients with different types of dementia. The trial took 6 weeks: 2 weeks to collect initial data; 2 weeks of intervention; and 2 weeks to collect final data. This trial was significant since it was the first study of ambient music which was not patient preferred. The results were strongly positive: adverse behaviours (e.g. wandering, aggression, verbal abuse) decreased by over 40% during the intervention period. However, the sample size of the trial was very small (n=14) so these results are not reliable.
When the researchers tried to replicate the study on a larger sample (n=75), their new results contrasted their previous findings, i.e. behavioural disturbances increased.[9] Therefore, we can conclude two ideas from these studies. Firstly, Baroque music does affect behaviour in dementia patients, since when Baroque music was played there was on average 0.2 more episodes of antisocial behaviour. Secondly, if music is to be used, it must be suited to each individual, since many patients in the study complained that the music was too loud or too fast.
Another study using Baroque music, specifically music from Antonio Vivaldi, was published in 2006.[10] The researchers used Vivaldi’s “Spring” movement from “The Four Seasons” to investigate whether music may improve autobiographical memory in patients with mild Alzheimer’s Disease (AD). The experiment consisted of an experimental group (n=10) and a group which had healthy elderly individuals (n=10), as a control. Using a repeated-measures design, they observed each participant twice: once in silence and once with the intervention. The participants with AD considerably improved in their Autobiographical Memory Interview in the music condition, when compared to their silent condition. Additionally, a significant reduction in state anxiety was found on the State Trait Anxiety Inventory in the music condition. The researchers suggested that anxiety reduction may be an underlying mechanism for music’s effects on improving autobiographical recall. The sample sizes of the trial are small, which decreases the reliability and does not actually prove that Baroque music causes these positive effects – it may just be a correlation.
Published in 2015, a study was conducted to evaluate the adjunct effect of music therapy in patients with AD.[11] The experiment consisted of a music therapy group (MTG) (n=20) and a control group (CG) (n=21) and lasted for 6 months. For MTG, the interventions included 30 minutes of listening to music via headphones in the morning and before going to sleep. Mozart’s Sonata (KV 448) was played in the morning and Pachelbel’s Canon was played before sleep. Outcome assessments included the Cognitive Abilities Screening Instrument (CASI) and CASI-estimated mini-mental state examination (MMSE). After 6 months, CASI and CASI-estimated MMSE scores in MTG were slightly less decreased than CG. Also, after the team conducted further analysis, they found that the adjusted difference of abstraction domain in the MTG was significantly better than the CG.
In one study, researchers played an excerpt from Mozart’s piano sonata and compared pre-intervention and post-intervention results of a spatial temporal task.[12] Their participants were a set of twins who were discordant for AD. After listening to the music, the AD twin showed considerable improvement on the spatial temporal task when compared with pre-intervention scores. Interestingly, no improvement was seen after the control interventions (which were silence and popular 1970’s music).
As well as passive music listening, many studies have used singing or singing training as their musical intervention, including a study which investigates the effects of singing training on the cognitive function of patients with AD.[13] The researchers conducted group music therapy using singing training at their hospital once a week for 6 months (n=10). The participants were assessed twice (before and after the 6-month intervention period) with an array of neuropsychological examinations and functional magnetic resonance imaging (fMRI). They concluded that psychomotor speed improved and the analysis with fMRI showed a reduction in the size of activated brain regions during the task performance, which suggested the organization of a new cognitive strategy in the brain. However, more trials are needed to confirm this, since the sample size is small.
Alongside traditional, simple music therapy interventions, many new conventional techniques are being researched, such as MINWii.[14] MINWii is a music therapy video game targeted towards demented patients, which lets players play songs of their choice or make up their own, using a virtual keyboard. A three-month study was conducted in a laboratory in Paris with seven AD patients. The study demonstrated that MINWii is usable by demented patients, despite their motor and cognitive impairments. After playing, patients improved their behaviour, were very satisfied and often wanted to play again, suggesting that it was a pleasant experience. This pilot study justifies further research in order to understand the long-term effects on dementia symptoms.
Overall, we can make four remarks from these studies about music therapy. Firstly, the term ‘music therapy’ includes a very wide range of interventions: it can include more traditional, orthodox methods such as listening to classical music or more conventional methods such as the MINWii video game. Secondly, we can – to a great degree of certainty – conclude that music has the potential to alleviate symptoms of dementia, albeit for a short time. Thirdly, music can have negative effects on a particular individual. Hence, demented patients should be strongly encouraged to try music therapy but only with the close guidance of their geriatrician or neurologist and a music therapist. Finally, more studies need to be conducted in order to improve the reliability of these results and also to discover the long-term effects.
Conclusion
Undoubtedly, music therapy has the potential to reduce cognitive decline and improve the quality of life of patients with dementia. Researches have proved that some faculties such as psychomotor speed improve after undergoing music therapy. However, the results of music therapy trials are inconsistent and there have been instances where music therapy has had adverse effects on particular individuals. Therefore, there should not be a universal approach: the strategy needs to be decided on a very specific and individual level, guided by the expertise of clinicians and approved by the consent of patients and their families, much like the treatment of cancer patients.
Lastly and most importantly, more clinical trials are needed to confirm the effects of music therapy. Ideally, the clinical trials need to be reproducible, randomized, controlled, methodical and more rigorous, in order to provide valid, accurate and reliable results.
Siddhant Patel Youth Medical Journal 2021
Bibliography
[1] W.H.O. (2019). Dementia. [Online] Available at: https://www.who.int/news-room/fact-sheets/detail/dementia (Accessed: 17 August 2020).
[2] Alzheimer’s Research UK. Statistics about dementia. [Online] Available at: https://www.dementiastatistics.org/statistics-about-dementia/ (Accessed: 17 August 2020).
[3] WebMD. What Are the Treatments for Dementia? [Online] Available at: https://www.webmd.com/alzheimers/dementia-treatments-overview#1 (Accessed: 19 August 2020)
[4] Wang R., and Reddy P. H. (2017). “Role of Glutamate and NMDA Receptors in Alzheimer’s Disease,” Journal of Alzheimer’s disease57,4. [Journal article] Available at: https://doi.org/10.3233/JAD-160763
[5] Hoffman, M. (2014). Picture of the Brain. [Online] Available at: https://www.webmd.com/brain/picture-of-the-brain#1 (Accessed: 16 July 2020).
[6] Limb, C.J. (2006). “Structural and functional neural correlates of music perception,” The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology 288,4. [Journal article] Available at: https://doi.org/10.1002/ar.a.20316
[7] Sugaya K., and Yonetani A. Your Brain on Music. [Online] Available at https://www.ucf.edu/pegasus/your-brain-on-music/ (Accessed: 17 July 2020)
[8] Heim C., Nair B.K., Mowbray D., and Tavender J. (2003). “Effects of ambient baroque music on patients with dementia,” Australasian Journal on Ageing 22,4. [Journal article] Available at: https://doi.org/10.1111/j.1741-6612.2003.tb00500.x
[9] Heim C., Nair B.K., Krishnan C., D’Este C., Marley J., and Attia, J. (2011). “The effect of Baroque music on behavioural disturbances in patients with dementia,” Australasian journal on ageing 30,1. [Journal article] Available at: https://doi.org/10.1111/j.1741-6612.2010.00439.x
[10] Irish M., Cunningham C.J., Walsh J.B., Coakley D., Lawlor B.A., Robertson I.H., and Coen R.F. (2006). “Investigating the enhancing effect of music on autobiographical memory in mild Alzheimer’s disease,” Dementia Geriatric Cognitive Disorders 22,1. [Journal article] Available at: https://doi.org/10.1159/000093487
[11] Li C.H., Liu C.K., Yang Y.H., Chou M.C., Chen C.H., and Lai C.L. (2015). “Adjunct effect of music therapy on cognition in Alzheimer’s disease in Taiwan: a pilot study,” Neuropsychiatric Disease and Treatment 11. [Journal article] Available at: https://doi.org/10.2147/NDT.S73928
[12] Johnson J.K., Cotman C.W., Tasaki C.S., and Shaw G.L. (1998). “Enhancement of spatial-temporal reasoning after a Mozart listening condition in Alzheimer’s disease: a case study,” Neurological Research 20,8. [Journal article] Available at: https://doi.org/10.1080/01616412.1998.11740582
[13] Satoh M., Yuba T., Tabei K., Okubo Y., Kida H., Sakuma H., and Tomimoto H. (2015). “Music Therapy Using Singing Training Improves Psychomotor Speed in Patients with Alzheimer’s Disease: A Neuropsychological and fMRI Study,” Dementia and Geriatric Cognitive Disorders Extra 5,3. [Journal article] Available at: https://doi.org/10.1159/000436960
[14] Boulay M., Benveniste S., Boespflug S., Jouvelot P., Rigaud A.S. (2011). “A pilot usability study of MINWii, a music therapy game for demented patients,” Technology and Health Care 19,4. [Journal article] Available at: https://doi.org/10.3233/THC-2011-0628
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