Neurobiological mechanism of music improving gait disorder in patients with Parkinson's disease: a mini review

Abstract

Walking ability is essential for human survival and health. Its basic rhythm is mainly generated by the central pattern generator of the spinal cord. The rhythmic stimulation of music to the auditory center affects the cerebral cortex and other higher nerve centers, and acts on the central pattern generator. By means of rhythm entrainment, the central pattern generator can produce walking rhythm synchronized with music rhythm, control muscle tension, and then regulate human gait. Basal ganglia dysfunction is the main cause of abnormal gait in patients with Parkinson's disease. Music therapy provides external rhythmic stimulation, recruits neural networks to bypass the basal ganglia and synchronizes gait with external rhythms in both time and space through auditory-motor neural networks, helping to promote the improvement of abnormal gait patterns in patients with Parkinson's disease.

Keywords: Parkinson’s disease; central pattern generator; gait; music; rhythmic entrainment.

Figure 1

The neural mechanism of music on gait in patients with Parkinson’s disease (22, 25, 38). Auditory information is conveyed from the cochlear nuclei to cortical auditory areas. PM, M1, and SMA generate precise motion and posture control commands. BG receives inputs from the cortical motor area, which is projected to the MLR through different subpopulations of neurons. MLR impinges on reticulospinal neurons to control the spinal CPGs for locomotion. In normal, the brain networks involved in gait regulation include motor cortex, BG, thalamus, cerebellum, MLR and CPG. The striatum in BG receives afferent projections from cortical motor area and thalamus. The cerebellum is conducted downward through their connections with the brainstem and upward to the cortex via the thalamus. In Parkinson’s disease, music guided movements recruits cerebello-thalamo-cortical motor network and thus bypasses the basal ganglia, as shown by the red arrows. CnF = cuneiform nucleus; CPG = central pattern generator; GPe = external globus pallidus; GPi = globus pallidus internus; M1 = primary motor cortex; MLR = mesencephalic locomotor region; PM = premotor area; PMRF = pontomedullary reticular formation; PPN = pedunculopontine nucleus; SMA = supplementary motor area; SNC = substantia nigra pars compacta; STN = subthalamic nucleus.