Alzheimer’s Disease (AD) is the most common type of dementia. The circadian system, which is controlled by the master clock in the Suprachiasmatic Nucleus (SCN) of the hypothalamus, is crucial for various physiological processes. Studies have shown that changes in the circadian rhythms can deteriorate neurodegenerative diseases. Changes in the SCN are associated with cognitive decline in AD. The cognitive impairments in AD, especially memory dysfunctions, may be related to Circadian Rhythm Disturbances (CRDs). Moreover, rhythmic expression of clock genes is disrupted in AD patients. There is a circadian pattern of inflammatory processes in AD, and dysregulation of core clock genes promotes neuroinflammation. The present narrative review addresses the intricate link between CRDs and AD, revisiting the relevant cellular and molecular mechanisms. The association between CRDs and AD highlights the need for further investigation of the underlying mechanisms.

Parkinson's Disease (PD) is a neurodegenerative disorder that affects motor and non-motor functions. Speech impairments, such as reduced variability in pitch (F0SD) and intensity (IntSD), are commonly observed. Early identification of these changes through voice biomarkers offers a noninvasive approach for detecting PD, tracking disease progression, and investigating the effects of interventions on this population. This study investigates the impact of dance on people with PD voice features over a five-year period and explores whether dance interventions can mitigate these impairments. A longitudinal dance program involved 29 individuals with PD and 29 healthy controls. Voice recordings were collected before and after dance sessions over 5 years (2014-2019) and analyzed using machine learning models to extract F0SD and IntSD. Statistical analyses, including ANOVA and mixed-effect models, were performed using R studio to evaluate group differences, longitudinal changes, and the effects of dance on voice parameters. The analysis revealed a significant main effect of time on F0SD, indicating measurable changes over the study period. However, the interaction between group and time was not statistically significant, suggesting similar trends in both groups. While the PD group did not exhibit the expected decline in F0SD seen in previous studies, IntSD remained largely unchanged, suggesting it may be less responsive to intervention. These findings demonstrate the potential of F0SD and IntSD as biomarkers for tracking PD progression. Dance interventions provide measurable benefits for F0SD, though further research is needed to determine optimal intervention duration and explore additional speech features such as jitter, shimmer, HNR, and CPP. Early and targeted interventions, such as combining dance with speech therapy, may enhance communication abilities and improve the quality of life for individuals with PD.

Background: Parkinson's disease (PD) is the most common neurodegenerative disorder after Alzheimer's disease, and is characterized by motor and non-motor symptoms, including gait dysfunction and cognitive decline. Dance has emerged as a promising intervention for improving motor and non-motor symptoms in persons with PD (PwPD), yet long-term effects remain underexplored. Objective: To assess changes in cognitive function and gait performance over six years among PwPD who participated in a weekly dance program, compared to a Reference group who remained physically inactive. Methods: This six-year longitudinal observational study included 43 PwPD who attended weekly dance classes and were evaluated using the Mini-Mental State Examination (MMSE) and Movement Disorder Society–Unified Parkinson's Disease Rating Scale (MDS-UPDRS). A Reference group of 28 PwPD, matched on age, gender, and Hoehn & Yahr scores, were selected from the Parkinson's Progression Marker Initiative, and assessed using the MDS-UPDRS and Montreal Cognitive Assessment (MoCA). Cognitive scores were standardized. Generalized estimating equations were used to compare cognitive and gait outcomes across time. Results: The Dance group was significantly different from the Reference group ( p < 0.001), with improved cognitive scores in 2016, 2017, and 2018. The Dance group had worse gait at baseline, however, the Reference group showed significantly poorer gait performance by 2018. In a subset of our data (n=10), no significant association was found between gait and cognitive scores. Conclusions: After two years of weekly dance, the Dance group showed improvements in cognition and maintained stability in gait performance. The findings highlight the potential neuroprotective benefits of continued dance engagement over six years.

Dance is an art form and simultaneously a form of exercise that provides pleasure to individuals who practise it regularly with subsequent improvements to motor and non-motor symptoms in people with Parkinson’s disease (PD). Recent evidence suggests that dance promotes neuroplasticity and correlates with improvements of depression scores in individuals with PD. However, no neuroplasticity studies using fMRI and EEG have been conducted on people with Parkinson’s disease (PwPD) who attend community dance programs. Thus, we present an observational examination across 7-years that explores the effects of non-motor symptoms of anxiety and depression. The study utilized multimodal recordings from functional MRI (fMRI), electroencephalogram (EEG) and measured affective state using the expanded version of the Positive and Negative Affect Schedule (PANAS-X) questionnaire. fMRI was performed at four time points in the first year (September, December, January, and May) where participants visualized/imagined the choreography they had learned in the dance studio while listening to the recording of the music in the MRI. Resting state EEG was recorded immediately before and after the dance class when the dancers volunteered over the 7 years. In addition, mood was monitored using the PANAS-X in conjunction with the EEG sessions. The PANAS-X was sorted by generalized anxiety disorder (positive and negative affect) symptoms, and major depressive disorder (positive and negative affect) symptoms, along with standard general negative affect (GNA) and general positive affect (GPA). This analysis reveals significant improvements in both symptoms after dance and across time. fMRI results show significant BOLD signal changes in the nucleus accumbens and anterior cingulate cortex, along with trends in other regions in the reward pathway such as the ventral tegmental area and the orbitofrontal cortex. rsEEG results show significant increases in alpha peak values after dance, in both EO and EC conditions. The findings support the idea that dance is a multimodal form of neurorehabilitation with beneficial effects on both motor and non-motor symptoms, including anxiety and depression.

Background: Parkinson’s Disease (PD) is the most common neurodegenerative disorder after Alzheimer’s, and is characterized by motor and non-motor symptoms, including gait dysfunction and cognitive decline. Dance has emerged as a promising intervention for improving motor and non-motor symptoms in persons with PD (PwPD), yet long-term effects remain underexplored. Objective: To assess changes in cognitive function and gait performance over six years among PwPD who participated in a weekly dance program, compared to a Reference group who remained physically inactive. Methods: This six-year longitudinal observational study included 43 PwPD who attended weekly dance classes and were evaluated using the Mini-Mental State Examination (MMSE) and Movement Disorder Society–Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). A Reference group of 28 PwPD, matched on age, gender, and Hoehn & Yahr scores, were selected from the Parkinson’s Progression Marker Initiative, and assessed using the MDS-UPDRS and Montreal Cognitive Assessment (MoCA). Cognitive scores were standardized. Generalized estimating equations were used to compare cognitive and gait outcomes across time. Results: The Dance group was significantly different from the Reference group ( p < 0.001), with improved cognitive scores in 2016, 2017, and 2018. The Dance group had worse gait at baseline, however, the Reference group showed significantly poorer gait performance by 2018. No significant association was found between gait and cognitive scores. Conclusion: After two years of weekly dance, the Dance group showed improvements in cognition and maintained stability in gait performance. The findings highlight the potential neuroprotective benefits of continued dance engagement over six years.

Background: Parkinson’s disease (PD) is a neurodegenerative disorder characterized by progressive motor and non-motor impairments, including speech deficits. Dance-based interventions have been proposed as a promising rehabilitative strategy for enhancing motor function, cognitive engagement, and neuroplasticity. However, the neural mechanisms underlying dance-induced neuroplasticity remain poorly understood. Objective: This study aimed to investigate the effects of an 8-month dance training program on functional brain activity, cortical structure, and white matter integrity in people with PD (PwPD) using a multi-modal neuroimaging approach. Methods: Ten individuals with PD participated in dance training and underwent functional MRI (fMRI) and cortical thickness analysis (T1-weighted MRI) at four time points, and 4 of them underwent diffusion-weighted imaging (DWI) at the last two time points. fMRI examined BOLD signal changes in the motor cortex (inferior frontal gyrus) and the supplementary motor area (SMA) during a dance-imagery task. Cortical thickness was measured in Broca’s area and the left supplementary frontal language (SFL) area. A reference group from the Michael J. Fox Foundation’s Parkinson’s Progression Markers Initiative (PPMI) dataset was selected for cortical thickness analysis. White matter integrity between Broca’s area and the SFL area was assessed using fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD). Additionally, fundamental frequency standard deviation (F0SD), a key indicator of speech prosody, was analyzed in three participants over a 5-year follow-up period to examine the functional relevance of neuroplastic changes. Results: Reductions in BOLD signal were observed in the motor cortex (inferior frontal gyrus) between September and January ( p = 0.021), suggesting increased neural efficiency. In contrast, SMA exhibited a significant increase in BOLD signal activity between September and January ( p = 0.010), indicating enhanced motor-speech integration. No further notable changes in functional activity in both regions were detected between January and April. The dance group showed significant changes in cortical thickness in the left SFL area across time, with increases from September to December ( p = 0.049) followed by decreases from December to April ( p = 0.046). However, no changes were detected in Broca’s area for the dance or reference groups. Additionally, the reference group did not exhibit any significant changes in the left SFL area across the same time points. FA increased significantly between January and April ( p = 0.024), suggesting enhanced white matter organization in speech-motor pathways. AD showed a marginal increase during this period ( p = 0.056), while RD and MD remained stable. Critically, voice feature analysis revealed significant improvements in F0SD over the 5-year follow-up period ( p < 0.0001), demonstrating sustained functional benefits in speech prosody that were associated with the earlier neuroplastic adaptations. Conclusion: Dance training was associated with significant functional and white matter neuroplastic changes in PD, particularly in motor-related functional activity and white matter connectivity between motor and language networks. The neuroplastic adaptations observed during the 8-month intervention period were associated with sustained improvements in speech prosody that persisted for years, providing compelling evidence for the clinical relevance of dance-induced brain changes. While dynamic cortical thickness changes were observed in the SFL area, the functional and structural connectivity adaptations appear to be the primary drivers of therapeutic benefit. These findings highlight dance as a promising, intervention for enhancing neural efficiency and motor-linguistic integration in PD, with demonstrated long-term functional benefits that warrant further investigation in larger, controlled studies.