Wearable Visual Cues in Parkinson's Disease

One of the most disabling features of Parkinson's disease (PD) is represented by the gait disturbances. Some systematic reviews and meta-analysis have showed that conventional physical therapy might improve gait as well as balance, mobility and functional reach in subjects affected by PD. In addition, several studies and reviews support the effectiveness of external sensory cueing, by means of rhythmic auditory or visual cues, in improving kinematic parameters of gait (gait cadence, stride length, velocity, and postural stability) and the functional performance in people with PD, at least in the short-term. Specifically, cueing refers to the use of temporal or spatial stimuli to regulate movement and facilitate functional performance for individual with motor dysfunction. Basal ganglia act as internal triggers of neuronal activity in the supplementary motor area for well-learned, automatic movement sequences, such as locomotion. This mechanism is damaged in individuals with PD, and external cues may act as an attention resource to compensate the deficient internal rhythm due to basal ganglia dysfunction. Subjects can be coached in concentrating their attention on gait by specific self-prompting instructions or by cues stimulation or a combination of these. Movements generated by the presence of external sensory cues are prompted to use alternative (cortical, parieto-premotor) neuronal pathways which have not been damaged by neuronal degeneration of PD, bypassing the automatic basal ganglia network. Recent studies have provided preliminary evidence that visual cueing based on laser shoes and laser canes may reduce freezing, an established risk for falls, with improvement that can be observed for a variable period of time after rehabilitative intervention. In light of the evidence of effectiveness of cueing, developing wearable devices able to generate cues that match with step and that are effective, easy to use and low cost, would be challenging but very appropriate