Music Therapy for Motor and Nonmotor Symptoms of Parkinson's Disease: A Prospective, Randomized, Controlled, Single-Blinded Study.

Abstract

To the Editor: Parkinson's disease (PD) is a common neurodegenerative disorder that affects adults.1 Mainly considered in the past as solely a motor disease, the coexistence of a complex set of nonmotor symptoms, including neuropsychiatric symptoms, has been confirmed.2 Lacking a cure, management consists of optimization of drug therapy and its implementation in addition to nonpharmacological treatments. One of the available alternative therapies is music therapy (MT), which uses music and its elements (sound, rhythm, melody, harmony) to promote mobilization and mental activation. To the knowledge of the authors, the effect of active MT on cognition in PD has not been explored. Twenty-five individuals with a diagnosis of PD,3 mild disability, and stable treatment who were free of dementia, depression, or serious comorbidity and were not undergoing treatment that would interfere with cognition were enrolled and randomly assigned to MT or no treatment (control). At baseline, at the end of the MT program (6 months), and 6 months after the end of MT program (12 months) all participants were evaluated for quality of life (QoL) and underwent a detailed motor and neuropsychological examination assessing executive function, attention, visuospatial skills, memory, and language. The motor examiner (ES) and the neuropsychologist (AL) were blinded to group assignment. MT sessions were held once a week for 24 weeks; each session lasted 90 minutes and consisted of production of music, singing, and dancing. Variations within each group over time in clinical and neuropsychiatric measures were assessed using the Wilcoxon test. Significance was set at P < .05. A beneficial effect of active MT on cognition was detected (Table 1). There was improvement at the end of the program on tests examining frontal lobe function (cognitive flexibility, processing speed, attention, working memory), suggesting that MT might enhance frontal function by acting as a training ground for these cognitive skills, given that producing music stimulates attention and executive functions such as planning, flexible thinking, and execution. Furthermore, improvement in memory was observed as reflected by increases in Rey immediate and delayed recall scores; again, active execution of music would stimulate memory processes through the flexible recovery of songs and motor sequences. These findings are consistent with those of previous studies reporting beneficial effects of MT on frontal function and memory in individuals with brain injury4 and mild cognitive impairment and dementia.5 Nevertheless, there were no significant differences between baseline and 6 months after the end of the program (Table 1), confirming that the beneficial effects of MT on cognitive performance tend to vanish after treatment ends. No significant variations were detected over time in control participants on any cognitive measures apart from isolated improvement on Rey immediate recall at the end of the intervention and deterioration in verbal fluency between the end of the intervention and 6 months later (Table 1); these variations were not significant from baseline to 12 months later, suggesting only insignificant cognitive fluctuations. Consistent with previous MT trials, significant improvement of QoL was found, especially for emotional well-being at the end of the intervention (Table 1), supporting the holistic effects of MT on emotional state; again, this beneficial effect regressed 6 months after treatment ended. Conversely, controls deteriorated on the 39-item Parkinson's Disease Questionnaire (PDQ-39) bodily discomfort and mobility subscales, in line with disease progression and, unexpectedly, improved on the cognition subscale in absence of improvement on any cognitive test, probably reflecting individuals’ fluctuating perceptions of their cognitive abilities. Regarding motor symptoms, there were no significant beneficial effects of MT on Movement Disorder Society Unified Parkinson's Disease Rating Scale or Timed Up and Go (TUG) scores (Table 1). In particular, there was no significant difference in TUG scores between baseline and the end of the intervention or 6 months later, but there was significant deterioration between the end of the intervention and 6 months later. This probably reflects a beneficial effect of active MT on gait and stability, as revealed by TUG total scores at baseline and the end of the intervention, in agreement with recent meta-analysis data;6 nevertheless this effect was not statistically significant in this population, maybe because of a large standard deviation within the groups or small sample size. The lack of deterioration from baseline to 6 months after the intervention would support this hypothesis. In addition, consistent with previous studies,7, 8 the beneficial effect of MT on gait and stability would disappear after discontinuation, as revealed by significant deterioration between the end of the intervention and 6 months later. Conversely, controls showed significant deterioration in TUG scores 1 and 3 between baseline and 6 months after the end of the intervention (Table 1), as would be expected in the natural progression of disease. The present pilot study shows, for the first time in PD, that active MT has a beneficial effect on frontal function, even though this effect tends to disappear after the intervention is stopped, suggesting that MT should be continued for longer. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: All authors participated in the conception, organization, and execution of the research project; writing, review, and critique of the first draft; final approval of the letter; and agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.