Effects of neuromodulation on postural control in individuals with Parkinson's disease

Abstract

Parkinson's disease (PD) is a neurological condition that is related to the degeneration of cells originate in the compact region of the substantia nigra. The clinical features of PD involve resting tremor, bradykinesia, postural instability, and rigidity. Of the limitations related to postural instability, imbalance is one of the most disabling, as it can result in falls. Recently, neuromodulation techniques such as transcranial direct current stimulation (tDCS) have been growingly used in neurofunctional rehabilitation with increasingly positive results; however, the effects of tDCS on motor losses in PD are not yet fully established. Thus, the aim of this study was to verify whether tDCS, together with physiotherapy, can optimize variables related to the gait and balance of individuals with PD (Study I); in addition, a systematic review was also proposed to observe the main studies that relate tDCS neuromodulation with the postural control of individuals with PD (Study II). Study I aimed to investigate the impact of consecutive anodic tDCS sessions through the supplementary motor area (SMA) together with a physical therapy program in individuals with PD. The results suggest that there were no significant group effects, but a moderate to large effect size was observed, indicating greater intervention effects for the UPDRS scale (part III) and Mini-BESTest. Study II, on the other hand, aimed to investigate how neuromodulation can act as an
instrument of therapeutic intervention to improve the control of postural stability in individuals with PD. The results suggest that the effects of tDCS neuromodulation in the control of postural stability are diversified, recommending more research on the topic.