Characterization of the vastus lateralis torque-length, and knee extensors torque-velocity and power-velocity relationships in people with Parkinson's disease.

Introduction: Parkinson's disease (PD) is a prevalent neurodegenerative condition observed primarily in the elderly population that gives rise to motor and non-motor symptoms, one of which is muscle weakness. The aim of this study was to characterize the vastus lateralis torque-fascicle length (T-L) and the knee extensors torque-angular velocity (T-V) and power-angular velocity (P-V) relationships in PD patients and to investigate the influence of muscle geometry on muscle mechanics. Methods: Participants (11 PD: patients, 9 CR: age matched healthy controls; 10 CY: young healthy controls) performed: (i) isometric contractions (e.g., MVC) to obtain the torque-angle and T-L relationships; (ii) isokinetic (e.g., iso-velocity) contractions to obtain the T-V and P-V relationships. During the experiments, the architecture of vastus lateralis (pennation angle, fascicle length, muscle thickness) was also determined by using an ultrasound apparatus. Results: Significant differences were observed between PD patients and physically matched control groups (CR and CY) in terms of maximum isometric force (calculated as the apex of the T-L curve) and maximum mechanical power (apex of the P-V curve), but not in maximum shortening velocity. Among the mechanical variables investigated, mechanical power was able to identify differences between the less and the more affected side in PD patients, suggesting that this parameter could be useful for clinical evaluation in this population. Conclusions: The observed results cannot be explained by differences in muscle geometry at rest (similar in the three cohorts), but rather by the muscle capacity to change in shape during contraction, that is impaired in PD patients.

Muscle shape changes in Parkinson's disease impair function during rapid contractions.

AIM: Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized, among the others, by muscle weakness. PD patients reach lower values of peak torque during maximal voluntary contractions but also slower rates of torque development (RTD) during explosive contractions. The aim of this study was to better understand how an impairment in structural/mechanical (peripheral) factors could explain the difficulty of PD patients to raise torque rapidly. METHODS: Participants (PD patients and healthy matched controls) performed maximum voluntary explosive fixed-end contraction of the knee extensor muscles during which dynamic muscle shape changes (in muscle thickness, pennation angle, and belly gearing: the ratio between muscle belly velocity and fascicle velocity), muscle-tendon unit (MTU) stiffness and EMG activity of the vastus lateralis (VL) were investigated. Both the affected (PDA) and less affected limb (PDNA) were investigated in patients. RESULTS: Control participants reached higher values of peak torque and showed a better capacity to express force rapidly compared to patients (PDA and PDNA). EMG activity was observed to differ between patients (PDA) and controls, but not between controls and PDNA. This suggests a specific neural/nervous effect on the most affected side. On the contrary, MTU stiffness and dynamic muscle shape changes were found to differ between controls and patients, but not between PDA and PDNA. Both sides are thus similarly affected by the pathology. CONCLUSION: The higher MTU stiffness in PD patients is likely responsible for the impaired muscle capability to change in shape which, in turn, negatively affects the torque rise.

Improvement in motor symptoms, physical fatigue, and self-rated change perception in functional motor disorders: a prospective cohort study of a 12-week telemedicine program.

BACKGROUND: Functional motor disorders (FMDs) are highly disabling conditions associated with long-term disability, poor quality of life, and economic burden on health and social care. While multidisciplinary 5-days rehabilitation programs have been shown to reduce motor and non-motor symptoms, long-term management and monitoring in FMDs remain an unmet need. AIM: To compare a 12-weeks telemedicine program against a 12-weeks self-management program after a 5-days rehabilitation program for improving motor, non-motor symptoms, quality of life, and perception of change in patients with FMDs. METHODS: The study population was 64 consecutive patients with a definite diagnosis of FMDs who underwent a 5-days in-person rehabilitation program followed by either a self-management (the first 32 patients) or a telemedicine program (the latter 32 patients). Validated measures of motor and non-motor symptoms such as fatigue and pain, quality of life, perception of change, gait, and postural control were recorded before (T0), after completion of rehabilitation (T1), and then again at 3 months (T2). RESULTS: Improvement at 3-month follow-up assessment of motor symptoms (p < 0.001), physical fatigue (p = 0.028), and self-rated change perception (p = 0.043) was greater in the telemedicine group. No different between-groups effect was found on other dimensions of fatigue, pain, physical and mental health, and gait and postural control. CONCLUSIONS: Long-term management and expert monitoring of patients with FMDs via telemedicine may enhance long-term outcomes in motor symptoms and physical fatigue, with a positive long-term impact on self-rated health perception of change.

Motor and non-motor outcomes after a rehabilitation program for patients with Functional Motor Disorders: A prospective, observational cohort study.

BACKGROUND: Rehabilitation has proven effective in improving motor symptoms (i.e., weakness, tremor, gait and balance disorders) in patients with Functional Motor Disorders (FMDs). Its effects on non-motor symptoms (NMSs) such as fatigue, pain, depression, anxiety and alexithymia, have not been explored yet. OBJECTIVE: To explore the effects of a validated inpatient 5-day rehabilitation program, followed by a home-based self-management plan on functional motor symptoms, NMSs, self-rated perception of change, and quality of life (QoL). METHODS: 33 FMD patients were enrolled. Measures for motor symptoms and NMSs were primary outcomes. Secondary outcomes included measures of self-perception of change and QoL. Patients were evaluated pre-treatment (T0), post-treatment (T1), and 3-month follow-up (T2). RESULTS: There was an overall significant decrease in functional motor symptoms, general, physical, and reduced-activity fatigue (for all, p < 0.001). Post hoc comparison showed significant improvements at T1, whereas effects remained significant at T2 for motor symptoms and physical fatigue. Gait and balance, alexithymia, and physical functioning (QoL) significantly improved at T2. More than 50% of patients reported marked improvement at T1 and T2. CONCLUSIONS: Our study suggests the benefits of rehabilitation and self-management plan on functional motor symptoms and physical fatigue in the medium-term. More actions are needed for the management of pain and other distressing NMSs in FMDs.

A physical therapy programme for functional motor symptoms: A telemedicine pilot study.

INTRODUCTION: for a proportion of patients with functional motor symptoms (FMS), specific physiotherapy has recently emerged as a promising treatment. Aim of the present study was to assess in a sample of patients with FMS the efficacy of a physical therapy-based telemedicine programme on the motor symptoms themselves and on some psychological variables such as anxiety, depression, alexithymia and quality of life. MATERIALS AND METHODS: eighteen patients were recruited. The programme consisted of 24 sessions: three face-to-face sessions (at week 0 (T0), 12 (T1) and 24 (T2)) and 21 tele-sessions. Each session included education, movement retraining exercises and development of a management plan. All patients underwent the following assessment at T0, T1 and T2: Psychogenic movement disorders rating scale (PMDRS), assessment of depression, anxiety, alexithymia and quality of life. Self-assessment of outcome (CGI) was recorded at T1 and T2. RESULTS: On the CGI improvement was reported by 66,7% of patients at T1 and 77,8% at T2. A significant improvement over the three time points was shown for PMDRS and for the following domains of the SF-36: general health, vitality, social functioning and mental health. CONCLUSION: the use of two innovative approaches for FMS (physiotherapy and telemedicine), combined together, might have a valuable role in the treatment of this neuropsychiatric condition.

The Moving Rubber Hand Illusion Reveals that Explicit Sense of Agency for Tapping Movements Is Preserved in Functional Movement Disorders.

Functional movement disorders (FMD) are characterized by motor symptoms (e.g., tremor, gait disorder, and dystonia) that are not compatible with movement abnormalities related to a known organic cause. One key clinical feature of FMD is that motor symptoms are similar to voluntary movements but are subjectively experienced as involuntary by patients. This gap might be related to abnormal self-recognition of bodily action, which involves two main components: sense of agency and sense of body ownership. The aim of this study was to systematically investigate whether this function is altered in FMD, specifically focusing on the subjective feeling of agency, body ownership, and their interaction during normal voluntary movements. Patients with FMD (n = 21) and healthy controls (n = 21) underwent the moving Rubber Hand Illusion (mRHI), in which passive and active movements can differentially elicit agency, ownership or both. Explicit measures of agency and ownership were obtained via a questionnaire. Patients and controls showed a similar pattern of response: when the rubber hand was in a plausible posture, active movements elicited strong agency and ownership; implausible posture of the rubber hand abolished ownership but not agency; passive movements suppressed agency but not ownership. These findings suggest that explicit sense of agency and body ownership are preserved in FMD. The latter finding is shared by a previous study in FMD using a static version of the RHI, whereas the former appears to contrast with studies demonstrating altered implicit measures of agency (e.g., sensory attenuation). Our study extends previous findings by suggesting that in FMD: (i) the sense of body ownership is retained also when interacting with the motor system; (ii) the subjective experience of agency for voluntary tapping movements, as measured by means of mRHI, is preserved.

Walking on four limbs: A systematic review of Nordic Walking in Parkinson disease.

Nordic Walking is a relatively high intensity activity that is becoming increasingly popular. It involves marching using poles adapted from cross-country skiing poles in order to activate upper body muscles that would not be used during normal walking. Several studies have been performed using this technique in Parkinson disease patients with contradictory results. Thus, we reviewed here all studies using this technique in Parkinson disease patients and further performed a meta-analysis of RCTs where Nordic Walking was evaluated against standard medical care or other types of physical exercise. Nine studies including four RCTs were reviewed for a total of 127 patients who were assigned to the Nordic Walking program. The majority of studies reported beneficial effects of Nordic Walking on either motor or non-motor variables, but many limitations were observed that hamper drawing definitive conclusions and it is largely unclear whether the benefits persist over time. It would appear that little baseline disability is the strongest predictor of response. The meta-analysis of the 4 RCTs yielded a statistically significant reduction of the UPDRS-3 score, but its value of less than 1 point does not appear to be clinically meaningful. Well-designed, large RCTs should be performed both against standard medical care and other types of physical exercise to definitively address whether Nordic Walking can be beneficial in PD.

Does the Pisa syndrome affect postural control, balance, and gait in patients with Parkinson's disease? An observational cross-sectional study.

INTRODUCTION: An altered sense of verticality, associated with impaired proprioception and somatosensory integration deficits, has been reported in patients with Parkinson's disease (PD) but it has not been characterized in patients with Pisa syndrome (PS). Therefore, we investigated postural control, balance, and gait disturbances in patients with PD and PS, patients with PD but without PS, and aged-matched normal controls. METHODS: This observational cross-sectional study involved patients with PD and PS (n = 10, Hoehn & Yahr score <4), patients with PD but without PS (n = 10), and age-matched healthy controls (n = 10). The primary outcome measure was the velocity of CoP displacement (VEL_MED_AP/ML) assessed by static stabilometry in eyes open (EO) and eyes closed (EC) conditions. The secondary outcomes were other stabilometric parameters, the Sensory Organization Balance Test (SOT), and gait analysis (GA). RESULTS: There were no significant differences in demographic and clinical data and Berg Balance Scale scores between the groups. There was a significant main effect in the VEL_MED_AP/ML between the groups and eye conditions (p = .016). A significant main effect was found in the EO (p = .01) and EC (p = .04) conditions. Post-hoc comparisons showed a significant increase in VEL_CoP in both the EO and EC conditions only in the patients with PD and PS. No significant main effects on SOT and GA were found. CONCLUSION: Patients with PD and PS had more difficulty achieving good postural alignment with gravity and greater velocity of body sway than the other groups. Rehabilitation programs for patients with PD and PS should include spine alignment and dynamic postural training.