OUR MECHANISM OF ACTION: ENTRAINMENT
ENTRAINMENT OVERVIEW
Music has been demonstrated to globally activate the human brain, including areas that are responsible for movement, language, attention, memory, executive function, and emotion. Specific to movement and walking, there is profound evidence that rhythm is able to engage the motor system to improve functional outcomes.
Studies have shown that audio-motor pathways exist in the Reticulospinal tract, the part of the brain responsible for movement. Priming and timing of movements via these pathways demonstrate the motor system's ability to couple with the auditory to drive movement patterns (Rossignol and Melville, 1976). This auditory-motor coupling has been termed entrainment.
Entrainment in gait rehabilitation
Rhythm enhances the brain at a brainstem level through the existence of audio-motor pathways via reticulospinal connection (Thaut, 2010). Auditory projections in the cerebellum have been shown via the pontine nuclei. Additionally, the inferior colliculi, one of the ascending auditory pathways, projects through the thalamus to the striatum and the basal ganglia. The basal ganglia maintains key projection to the cortical structures, including the supplementary motor cortex and pre-motor cortex (Thaut, 2010). In addition, the auditory association areas project back to the basal ganglia, and influence the function of timing and sequencing selection. Entraining to an external auditory cue while walking has been shown to effectively increase walking speed (Cha, 2014), decrease gait variability (Wright, 2016), and lower fall risk (Trombetti, 2011).
RELATIONSHIP TO NEUROPLASTICITY
Neuroplasticity refers to the brain’s ability to strengthen pre-existing neural connections or create new connections, allowing an individual to acquire skills over time or allowing the injured brain to heal. No matter one’s age, the brain possesses the unique ability and power to heal itself when exposed to the appropriate stimuli. Music induces the neurological connections necessary for the positive rewiring of the brain in certain regions. There is conclusive evidence that music can restore impaired neural processes or neural connections by engaging and linking brain centers that might otherwise not be linked together. (Schlaug, 2009).
An important study by Moore et al. validates these concepts by proving that music-cued motor-training facilitates a change in a brain region called the arcuate fasciculus, which plays an important role in motor planning (Moore et al, 2017). These changes in brain anatomy are evidence that music promotes neuroplasticity, especially in areas involved in movement.
CLINICAL RESEARCH IN RHYTHMIC AUDITORY STIMULATION
STRONG RESEARCH
Over 50 clinical studies demonstrate improvements in movement when using RAS (Rhythmic Auditory Stimulation). Specifically, walking speed has been shown to be highly correlated to fall risk. A study showed that each 0.1 m/s increase in walking speed was correlated to a 7% decrease in fall risk (Verghese et al., 2009).
MARKED IMPROVEMENT
Randomized Control Trials in multiple indications, including stroke, MS, Cerebral Palsy, and PD, demonstrated improved walking when RAS was delivered. (Suh et al., 2014; Conklyn, et al., 2010; Kim, et al., 2012; Bukowska, et al., 2016).
BETTER THAN STANDARD OF CARE
RAS is better than standard of care, as shown in RCT that yielded better outcomes than physical therapy in stroke patients (Thaut, 1997).
SCIENTIFIC PUBLICATIONS
Click here to read “Using Digital Therapeutics to Improve Outcomes,” an article that was authored by MedRhythms and published in Volume 13, Issue 4 of The Challenge!, a journal established by the Brain Injury Association of America. The following are some additional resources:
Moore, Emma et al. “Diffusion tensor MRI tractography reveals increased fractional anisotropy (FA) in arcuate fasciculus following music-cued motor training.” Brain and Cognition. Vol. 116, August, 2017.
Peretz, Isabelle and Robert J. Zatorre, "Brain Organization for Music Processing," Annual Review of Psychology, vol. 56, 2005.
Sacks, Oliver, Musicophelia: Tales of Music and the Brain, 2007.
Schlaug, Gottfried et al., "Music Listening and Music Making in the Treatment of Neurological Disorders and Impairments," Music Perception, vol. 27, no. 4, 2010.
Thaut, Michael H., "Entrainment and the Motor System," Music Therapy Perspectives, vol. 31, 2013.
Thaut, Michael H., “Neurologic Music Therapy in Cognitive Rehabilitation,” Music Perception, vol. 27, no. 4, 2010.
Thaut, Michael H. et al. "Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system." Frontiers in Psychology. Vol. 5, February 18, 2015.
Thaut, Michael H. and Gerald C. McIntosh, “How Music Helps to Heal the Injured Brain: Therapeutic use Crescendos Thanks to Advances in Brain Science,” Cerebrum, March 2010.
Thaut, Michael H. and Mutsumi Abiru, “Rhythmic Auditory Stimulation in Rehabilitation of Movement Disorders: A Review of Current Research,” Music Perception, vol. 27, no. 4, 2010.
