Parkinson App SmarTphone Aimed to Improve Walking Ability and Reduce Fall (P.A.S.T.A.)

Parkinson's disease (PD) is a chronic and progressive movement disorder, mainly due to an altered motor control. Gait impairments are the primary symptoms in patients with PD, with a decreased step length and walking speed, abnormal gait phases distribution, inconstant pace, gait asymmetry and reduced joint coordination. The postural instability and the deterioration of the gait features sensibly increase the risk of falls in these patients, resulting in loss of independence and a worsening of long-term prognosis. It has been clearly demonstrated that motor impairments are connected to a dysfunction of basal ganglia, a brain structure that works as a "pacemaker" for the activation (and deactivation) of each sub-movement within a repetitive movement sequence. Disruption of internal rhythmic cues in PD may explain the poor smoothness of the movement execution and the difficulties in regulating stride length, resulting in a cadence increase. Levodopa therapy is the most effective treatment to improve the symptoms in PD, but a long-term administration reduces its efficiency over time and it is responsible for collateral effects (dyskinesia). Hence, researches have investigated alternative non-pharmacological approaches, based on auditory cues as the Rhythmical Auditory Stimulation (RAS). A large number of studies have reported positive effects both after a single session of treatment and after longer training programs, with improved gait velocity, cadence, and stride length as well as in the symmetry of muscle activation for upper and lower extremities. In such studies, RAS frequencies are pre-set as percentages of the patient's preferred walking frequency. Because the duration of all the therapies may change over time, it is necessary a continuous adjustment of the dosage and type of treatment, based both on patients' monitoring of the symptoms and on objective evaluations. Gait analysis (GA) methods have been proposed and validated for the study of physiologic gait and in several diseases. The traditional systems of GA are based on optoelectronic systems, but they are expensive, not portable and requiring skilled operators. The assessment is always performed in laboratories with experimental set-ups, likely different from real-life walking (noise environments, presence of objects and people or unlevelled pavement, different colors).

Consequently, traditional GA is not reliable for the daily control of the treatments or for the assessment of the real-life situations. Recently, researchers have developed wearable systems, based on Inertial Measurement Units (IMUs). Even if a considerable number of studies have explored the validity of IMUs analysis, very few have been involved in PD motion analyses. During the last few years, a set of wearable devices embedding inertial sensors, are spread on the market as low-cost solutions for monitoring human motion activities. While, they still have to be fully validated in accuracy, these systems can provide the user information to track his/her own activity. This persuasive technology has a terrific potential to enhance physical activity and motivation of the patients, with the advantage of prolonged and continuous recording.

The use and the analyses of a large amount of objective data (big data set) is the new frontier for an efficient use of scientific time and resources, engaging the care coordination program, saving economic resources, and providing a higher quality of care. In addition, these systems, integrated with a web-based application, telemedicine and mobile smartphones, could help clinicians to address more properly the treatments through a real-time monitoring in an everyday life. Our research group has been involved in the clinical evaluation of different aspects of gait quality in many neurological conditions, PD included. Investigators have already shown as wearable accelerometers could be useful in the quantitative assessment of the dynamic gait stability, in correlation with clinical scores. Researchers have also found that accelerations could be altered in a pathology-specific manner (intellectual disabilities performing different tasks simultaneously). A similar condition can be observed also in PD, showing that only the intrinsic gait harmony significantly correlate with severity of gait impairments. In the recent years, a lot of wearable tools have become available to quantify the daily activity. This is particularly important for possible therapeutic use of the RAS, that is addressed to restore a harmonic pace in patients with PD.

Specific Aim 1: To analyze motor pattern in PD patients in real life setting, gait features will be obtained by wearable sensors in order to relate them with clinical and demographical data.

Specific Aim 2: To improve walking abilities and to reduce the risk of falls in patients with PD, researchers will test a real-time acoustic feed-back (RAS) and alerts from integrated sensors connected with a suitable and easy-to-use application for smartphones.