Assessment of the psychometric properties of the Italian version of the New Freezing of Gait Questionnaire (NFOG-Q-IT) in people with Parkinson disease: a validity and reliability study

IntroductionFreezingof gait (FOG) in Parkinson's disease (PD) is a challenging clinical symptom to assess, due to its episodic nature. A valid and reliable tool is the New FOG Questionnaire (NFOG-Q) used worldwide to measure FOG symptoms in PD.ObjectiveThe aim of this study was to translate, to culturally adapt, and to test the psychometric characteristics of the Italian version of the NFOG-Q (NFOG-Q-It).MethodsThe translation and cultural adaptation was based on ISPOR TCA guidelines to finalize the 9-item NFOG-Q-It. Internal consistency was assessed in 181 Italian PD native speakers who experienced FOG using Cronbach's alpha. Cross-cultural analysis was tested using the Spearman's correlation between the NFOG-Q-It and the Modified Hoehn-Yahr Scale (M-H&Y).To assess construct validity, correlations among NFOG-Q-It, Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Falls Efficacy Scale-International (FES-I), the 6-min Walking Test (6MWT), the Mini Balance Evaluation System Test (Mini-BESTest) and the Short Physical Performance Battery (SPPB) were investigated.ResultsThe Italian N-FOGQ had high internal consistency (Cronbach's alpha = 0.859). Validity analysis showed significant correlations between NFOG-Q-IT total score and M-H&Y scores (r = 0.281 p < 0.001), MDS-UPDRS (r = 0.359 p < 0.001), FES-I (r = 0.230 p = 0.002), Mini BESTest (r = -0.256 p = 0.001) and 6MWT (r = -0.166 p = 0.026). No significant correlations were found with SPPB, MOCA and MMSE.ConclusionThe NFOG-It is a valuable and reliable tool for assessing FOG symptoms, duration and frequency in PD subjects. Results provide the validity of NFOG-Q-It by reproducing and enlarging previous psychometric data

Neural oscillations during motor imagery of complex gait: an HdEEG study

The aim of this study was to investigate differences between usual and complex gait motor imagery (MI) task in healthy subjects using high-density electroencephalography (hdEEG) with a MI protocol. We characterized the spatial distribution of alpha- and beta-bands oscillations extracted from hdEEG signals recorded during MI of usual walking (UW) and walking by avoiding an obstacle (Dual-Task, DT). We applied a source localization algorithm to brain regions selected from a large cortical-subcortical network, and then we analyzed alpha and beta bands Event-Related Desynchronizations (ERDs). Nineteen healthy subjects visually imagined walking on a path with (DT) and without (UW) obstacles. Results showed in both gait MI tasks, alpha- and beta-band ERDs in a large cortical-subcortical network encompassing mostly frontal and parietal regions. In most of the regions, we found alpha- and beta-band ERDs in the DT compared with the UW condition. Finally, in the beta band, significant correlations emerged between ERDs and scores in imagery ability tests. Overall we detected MI gait-related alpha- and beta-band oscillations in cortical and subcortical areas and significant differences between UW and DT MI conditions. A better understanding of gait neural correlates may lead to a better knowledge of pathophysiology of gait disturbances in neurological diseases

Home-based exercise training by using a smartphone app in patients with Parkinson’s disease: a feasibility study

BackgroundParkinson’s disease (PD) patients experience deterioration in mobility with consequent inactivity and worsened health and social status. Physical activity and physiotherapy can improve motor impairments, but several barriers dishearten PD patients to exercise regularly. Home-based approaches (e.g., via mobile apps) and remote monitoring, could help in facing this issue.ObjectiveThis study aimed at testing the feasibility, usability and training effects of a home-based exercise program using a customized version of Parkinson Rehab® application.MethodsTwenty PD subjects participated in a two-month minimally supervised home-based training. Daily session consisted in performing PD-specific exercises plus a walking training. We measured: (i) feasibility (training adherence), usability and satisfaction (via an online survey); (ii) safety; (iii) training effects on PD severity, mobility, cognition, and mood. Evaluations were performed at: baseline, after 1-month of training, at the end of training (T2), and at 1-month follow-up (T3).ResultsEighteen out of twenty participants completed the study without important adverse events. Participants’ adherence was 91% ± 11.8 for exercise and 105.9% ± 30.6 for walking training. Usability and satisfaction survey scored 70.9 ± 7.7 out of 80. Improvements in PD severity, mobility and cognition were found at T2 and maintained at follow-up.ConclusionThe home-based training was feasible, safe and seems to positively act on PD-related symptoms, mobility, and cognition in patients with mild to moderate stage of PD disease. Additionally, the results suggest that the use of a mobile app might increase the amount of daily physical activity in our study population. Remote monitoring and tailored exercise programs appear to be key elements for promoting exercise. Future studies in a large cohort of PD participants at different stages of disease are needed to confirm these findings

Features and neural correlates of gait in Parkinson's disease

The primary objective of the studies conducted over my PhD was to better understand the neurophysiological basis of usual and complex gait in healthy subjects and in people with PD. To reach this aim, we used two innovative methods, AO and MI, which showed to recruit networks similar to the ones recruited during real movements, and three main instruments: a neuromodulatory technique, namely tDCS, and two neuroimaging methods, i.e., fMRI and EEG. Primarily, we decided to study the use of a single session of anodal tDCS, for a better dealing of gait associated to another cognitive or motor task in patients with PD. We used the left dorsolateral prefrontal cortex as target, and we performed a double blind, randomized and sham-controlled study. Protocol consisted in two gait evaluations before and after 20 minutes of stimulation during which patients had to walk on a sensorized mat, while making a serial subtraction and while crossing an obstacle. Subsequently, we introduced the use of AO, in order to study neural activations related to gait in patients with PD with and without FOG and in healthy controls. In this instance, participants had to carefully observe a video of a man walking during a fMRI recording. Indeed, it is now established, that the observation of actions of the motor repertoire of the subject is able to activate the so-called MNS, a particular population of neurons which is working both while we perform, or we see an action. During data analysis of this work, we questioned about structural impairments in PD patients with and without FOG, focusing on gait-related areas. This question was thus elaborated in a consequent work present on this thesis. Finally, we added another interesting technique, with similar fundamentals to AO, that is MI. In fact, our aim was to understand if an EEG protocol based on visual MI was able to recruit gait-related networks: 16 healthy young subjects, 14 healthy elderly subjects, and 15 patients with PD were instructed to imagine walking, with eyes open, in different pictures showed on a laptop screen. Regarding healthy subjects, the images represented a usual walking condition and a \u201ccomplex\u201d condition, which consisted in performing a MI of walking plus \u201ccrossing\u201d a hurdle positioned in the middle of the path. Our main interest was to highlight the differences in neural activations between usual and \u201cchallenging\u201d conditions. Regarding PD and healthy elderly, we were interested in the study of neural activations only related to the usual walking MI task. However, in general, the works reported in this thesis want to be a base for the construction of new and easy to manage rehabilitative programs for patients with Parkinson\u2019s Disease

Functional Correlates of Action Observation of Gait in Patients with Parkinson’s Disease

Background. Action observation (AO) relies on the mirror neuron system (MNS) and has been proposed as a rehabilitation tool in Parkinson’s disease (PD), in particular for gait disorder such as freezing of gait (FOG). In this study, we aimed to explore the brain functional correlates of the observation of human gait in PD patients with (FOG+) and without (FOG-) FOG and to investigate a possible relationship between AO-induced brain activation and gait performance. Methods. Fifty-four participants were enrolled in the study (15 PD FOG+; 18 PD FOG-; 21 healthy subjects (HS)) which consisted of two tasks in two separate days: (i) gait assessment and (ii) task-fMRI during AO of gait. Differences between patients with PD (FOG+ and FOG-) and HS were assessed at the level of behavioral and functional analysis. Results. Gait parameters, including gait velocity, stride length, and their coefficients of variability (CV), were different in PD patients compared to HS, whereas gait performance was similar between FOG+ and FOG-. The PD group, compared to HS, presented reduced functional activation in the frontal, cingulum, and parietooccipital regions. Reduced activity was more pronounced in the FOG+ group, compared to both HS and FOG- groups. Gait variability positively correlated with precuneus neural activity in the FOG+ group. Discussion. Patients with PD present a reduced functional activity during AO of gait, especially if FOG+. A baseline knowledge of the neural correlates of AO of gait in the clinical routine “on” status would help for the design of future AO rehabilitative interventions

One cue does not fit all: a systematic review with meta-analysis of the effectiveness of cueing on freezing of gait in Parkinson's disease

The difficulty in assessing FOG and the variety of existing cues, hamper to determine which cueing modality should be applied and which FOG-related aspect should be targeted to reach personalized treatments for FOG. This systematic review aimed to highlight: i) whether cues could reduce FOG and improve FOG-related gait parameters, ii) which cues are the most effective, iii) whether medication state (ON-OFF) affects cues-related results. Thirty-three repeated measure design studies assessing cueing effectiveness were included and subdivided according to gait tasks (gait initiation, walking, turning) and to the medication state. Main results reveal that: preparatory phase of gait initiation benefit from visual and auditory cues; spatio-temporal parameters (e.g., step and stride length) and are improved by visual cues during walking; turning time and step time variability are reduced by applying auditory and visual cues. Some findings on the potential benefits of cueing on FOG and FOG gait-related parameters were found. Questions remain about which are the best behavioral strategies according to FOG features and PD clinical characteristics

Image_1_Transcranial direct current stimulation alters sensorimotor modulation during cognitive representation of movement.TIFF

We recently demonstrated, by means of short latency afferent inhibition (SAI), that before an imagined movement, during the reaction time (RT), SAI decreases only in the movement-related muscle (sensorimotor modulation) and that a correlation exists between sensorimotor modulation and motor imagery (MI) ability. Excitatory anodal transcranial direct current stimulation (a-tDCS) on M1 could enhance the MI outcome; however, mechanisms of action are not completely known. Here, we assessed if a-tDCS on M1 prior to an MI task could affect sensorimotor modulation. Participants imagined abducting the index or little finger in response to an acoustic signal. SAI was evaluated from the first dorsal interosseus after the “go” signal, before the expected electromyographic (EMG) activity. Participants received 20-min 1.5 mA a-tDCS or sham-tDCS on M1 on two different days, in random order. Results showed that a-tDCS on M1 increases the sensorimotor modulation consisting of a weakening of SAI after the Go signal with respect to sham-tDCS, in the movement-related muscle right before the beginning of MI. These results suggest that a-tDCS on M1 further potentiate those circuits responsible for sensorimotor modulation in the RT phase of MI. Increased sensorimotor modulation during MI may be one of the mechanisms involved in MI improvement after a-tDCS over M1.</p

Haptic perception of verticality correlates with postural and balance deficits in patients with Parkinson's disease

Introduction: Perception of verticality is fundamental for postural stability that is often impaired in patients with Parkinson's disease (PD). Haptic perception of verticality has not been fully investigated in PD. The aim of the study was to assess subjective haptic vertical (SHV) in PD patients in relation to postural and balance impairments. Methods: 39 PD patients (mean age 72.87 \ub1 5.78) and 28 gender and age-matched healthy elderly (ELD, mean age 69.16 \ub1 13.89) were enrolled. The Pull test and the Activities-specific Balance Confidence (ABC) were used for evaluating balance performance, whereas measurement of posture was performed using the Physical Analyzer System\uae. For evaluating SHV, participants were instructed to provide their subjective vertical by manipulating with two hands a road while standing with their eyes closed. Results: SHV data showed that PD subjects had a greater deviation from the objective vertical than controls (p &lt; 0.001). Significant differences in balance performance (ABC and Pull test) and postural alignment were found between PD and ELD. Only in PD participants, SHV deviations significantly correlated with the lateral inclination of the trunk (r = 0.618, p &lt; 0.001), pull test (r = 0.519; p = 0.001) and ABC (r = 0.471, p = 0.002) scores. Conclusions: The perception of verticality, driven by multimodal sensory integration, is defective in PD subjects. Deficits in SHV correlated with postural alignment and balance performances, independently from age, disease severity or cognitive decline. Our findings support that PD pathology is associated with a decline in haptic perception suggesting that perception per se might have a causal role in postural and balance deficits