Discussion of Research Priorities for Gait Disorders in Parkinson's Disease

Abstract

Gait and balance abnormalities develop commonly in Parkinson's disease and are among the motor symptoms most disabling and refractory to dopaminergic or other treatments, including deep brain stimulation. Efforts to develop effective therapies are challenged by limited understanding of these complex disorders. There is a major need for novel and appropriately targeted research to expedite progress in this area. The Scientific Issues Committee of the International Parkinson and Movement Disorder Society has charged a panel of experts in the field to consider the current knowledge gaps and determine the research routes with highest potential to generate groundbreaking data. © 2021 International Parkinson and Movement Disorder Society.

Keywords: FOG; Parkinson's disease; balance; freezing; gait; research priorities.

Figure 1.

Motor network of posture/gait control. A fundamental circuitry between the brainstem (including the pedunculopontine nucleus/ mesencephalic locomotor region [PPN/MLR]) and the spinal cord via the brainstem–spinal cord (BS-SC) pathways contributes to the generation of locomotor rhythms and the regulation of postural muscle tone. Signals from the motor cortex (CTX) conducted through the lateral corticospinal tract (CST) to the brainstem and spinal cord contribute to volitional gait control. The regulation of appropriate postural balance and gait mediated by the basal ganglia and the cerebellum is conducted downward through their connections with the brainstem and upward to the cortex via the thalamus. CPG, central pattern generator.

Figure 2.

Multiple systems network in posture/gait control. Cognitive, emotional, and sensory (visual, auditory, vestibular, and proprioceptive) signals influence various nodes of the motor network (cortex, basal ganglia, cerebellum, brainstem). In addition, multiple interactions between the sensory, limbic, and cognitive systems modulate motor behaviors, including gait and postural control. For example, the limbic system has dense connections with the prefrontal cortex (CTX) and the basal ganglia. The parietal, temporal, and occipital association cortices connect with the prefrontal cortex (cognitive system) via dorsal and ventral pathways. Descending motor signals are further integrated with proprioceptive sensory signals at the level of the spinal cord. BS-SC, brainstem–spinal cord; CPG, central pattern generator; CST, corticospinal tract.