Denise Anastasi

Subjects with Parkinson’s Disease (PD) display different motor and non-motor symptoms. Different therapies have been shown to be effective, such as plantar foot stimulation, which has proved to be effective for motor symptoms. Different stimulation methods were proposed and tested through specific devices, or insoles. Our aim was to assess the effect of a newly designed custom-made insole called PRO-STEP compared with a flat sham insole on subjects with PD. Subjects were randomized 1:1 into two arms and were asked to wear PRO-STEP or sham insoles for at least 6 h per day for 10 weeks. Participants were evaluated at four timepoints. Forty-two subjects were randomly assigned to the PRO-STEP (EG) or sham group (SG). The comparison of the EG and SG without and with insoles (T0–T1) did not show significant differences in the TUG time and in the 10MWT gait parameters. At T1, T2, and T3 TUG time, BBS, SF12-MC, and SF12-PC did not show significant differences. The satisfaction level with the PRO-STEP or sham insoles was high in both groups. PD patients were satisfied with PRO-STEP insoles; however, plantar foot stimulation is not effective from a functional perspective. Future studies should consider possible modifications to the proposed stimulation to improve its effectiveness in patients with PD.

Limited longitudinal studies have been conducted on gait impairment progression overtime in non-disabled people with multiple sclerosis (PwMS). Therefore, a deeper understanding of gait changes with the progression of the disease is essential. The objective of the present study was to describe changes in gait quality in PwMS with a disease duration ≤ 5 years, and to verify whether a change in gait quality is associated with a change in disability and perception of gait deterioration. We conducted a multicenter prospective cohort study. Fifty-six subjects were assessed at baseline (age: 38.2 ± 10.7 years, Expanded Disability Status Scale (EDSS): 1.5 ± 0.7 points) and after 2 years, participants performed the six-minute walk test (6MWT) wearing inertial sensors. Quality of gait (regularity, symmetry, and instability), disability (EDSS), and walking perception (multiple sclerosis walking scale-12, MSWS-12) were collected. We found no differences on EDSS, 6MWT, and MSWS-12 between baseline and follow-up. A statistically significant correlation between increased EDSS scores and increased gait instability was found in the antero-posterior (AP) direction (r = 0.34, p = 0.01). Seventeen subjects (30%) deteriorated (increase of at least 0.5 point at EDSS) over 2 years. A multivariate analysis on deteriorated PwMS showed that changes in gait instability medio-lateral (ML) and stride regularity, and changes in ML gait symmetry were significantly associated with changes in EDSS (F = 7.80 (3,13), p = 0.003, R² = 0.56). Moreover, gait changes were associated with a decrease in PwMS perception on stability (p < 0.05). Instrumented assessment can detect subtle changes in gait stability, regularity, and symmetry not revealed during EDSS neurological assessment. Moreover, instrumented changes in gait quality impact on subjects’ perception of gait during activities of daily living.

Dynamic balance disorders are common impairments in People with Multiple Sclerosis (PwMS) leading to gait disorders and a higher risk of falling. However, the assessment of dynamic balance is still challenging and instrumented indexes provide objective and quantitative data of CoM movement and Base of Support, which are considered that are two key factors describing dynamic balance. This study aims at validating recent instrumented indexes based on the inverted pendulum model and characterizing dynamic balance disorders in PwMS. We clinically assessed 20 PwMS and we collected instrumented gait data through an optoelectronic system. Data from 20 Healthy Subjects (HS) were also considered as normative reference. Margin of Stability by HoF (MoS_Hof) and by Terry (MoS_Terry) at midstance, and Foot Placement Estimator (D_FPE) at heel strike were calculated in mediolateral (ML) and anteroposterior (AP) directions, for both less affected and most affected sides for PwMS and for dominant and non-dominant side for HS. MoS_HOF well discriminated between PwMS and HS, followed by MoS_TERRY in ML direction (Mos_HOF: PwMS = 130.0 ± 27.2 mm, HS = 106.5 ± 18.6 mm, p < 0.001, MoS_TERRY: PwMS = 75.1 ± 24.3 mm, HS = 56.5 ± 23.4 mm, p < 0.02). MoS_HOF and MoS_TERRY discriminated between sides in both directions in PwMS. D_FPE did not discriminate between groups and sides. Moderate correlations were found between all three indexes and clinical balance scales (from r = 0.02 to r = 0.66), energy recovery (from r = −0.77 to r = −0.11), single stance time (from r = −0.11 to r = 0.80) and step length (from r = −0.83 to r = −0.20). MoS_HOF resulted in the best index to describe dynamic balance disorders in PwMS: they keep CoM position far from the lateral and as close as possible to the anterior boundary of the Base of Support as preventive strategies to control balance perturbations. Furthermore, PwMS seem to use different preventive strategies in accordance with the specific lower limb impairments. This alters the physiological gait mechanisms increasing the energy expenditure and decreasing gait quality and dynamic balance.

The balance of people with multiple sclerosis (PwMS) is commonly assessed during neurological examinations through clinical Romberg and tandem gait tests that are often not sensitive enough to unravel subtle deficits in early-stage PwMS. Inertial sensors (IMUs) could overcome this drawback. Nevertheless, IMUs are not yet fully integrated into clinical practice due to issues including the difficulty to understand/interpret the big number of parameters provided and the lack of cut-off values to identify possible abnormalities. In an attempt to overcome these limitations, an instrumented modified Romberg test (ImRomberg: standing on foam with eyes closed while wearing an IMU on the trunk) was administered to 81 early-stage PwMS and 38 healthy subjects (HS). To facilitate clinical interpretation, 21 IMU-based parameters were computed and reduced through principal component analysis into two components, sway complexity and sway intensity, descriptive of independent aspects of balance, presenting a clear clinical meaning and significant correlations with at least one clinical scale. Compared to HS, early-stage PwMS showed a 228% reduction in sway complexity and a 63% increase in sway intensity, indicating, respectively, a less automatic (more conscious) balance control and larger and faster trunk movements during upright posture. Cut-off values were derived to identify the presence of balance abnormalities and if these abnormalities are clinically meaningful. By applying these thresholds and integrating the ImRomberg test with the clinical tandem gait test, balance impairments were identified in 58% of PwMS versus the 17% detected by traditional Romberg and tandem gait tests. The higher sensitivity of the proposed approach would allow for the direct identification of early-stage PwMS who could benefit from preventive rehabilitation interventions aimed at slowing MS-related functional decline during neurological examinations and with minimal modifications to the tests commonly performed.

Background: Heat sensitivity occurs in a high percentage of people with multiple sclerosis (PwMS), in response to environmental or exercise-induced increase in body temperature. However, the kinetic and magnitude of adaptation of the internal load and of the core body temperature (CBT) to a submaximal continuous exercise has been poorly addressed in PwMS; this may be relevant for the brief exercise bouts usually occurring in normal daily life. The aim of this work was to evaluate whether multiple sclerosis influences the acute adaptation of the internal load, the CBT and the perceptual load in response to a constant submaximal work step.Methods: CBT has been continuously monitored (0.5 Hz) by a validated wearable heat-flux sensor and electrocardiography was recorded (250 Hz) by a wearable device during a standard 6-minute walk test (6MWT) in 14 PwMS (EDSS, 4.7 ± 1.2; disease duration: 13.0 ± 10.2 years; m ± SD) and 14 age, sex and BMI-matched healthy subjects (HS). The rate of perceived exertion (RPE) of the lower limbs was assessed during the 6MWT by the Borg scale (6-20).Results: As expected, PwMS walked a significantly shorter distance (361 ± 98 m) than the HS group (613 ± 62 m, p<0.001 vs PwMS). However, the kinetics of adaptation of CBT and the magnitude of CBT change from baseline did not differ between groups. Similarly, heart rate (HR) kinetics and HR change from baseline were comparable between groups during the 6MWT. Finally, lower limbs RPE gradually increased during the exercise test, but without significant differences between groups.Conclusion: The internal load, the metabolic heat production, and the perceptive load due to a standard submaximal walking exercise seems to be preserved in PwMS, suggesting a comparable acute heat production and dissipation during exercise. Therefore, it is unlikely that the different distance achieved during the 6MWT may be caused by altered thermoregulatory responses to exercise. Rather, this appears to be a consequence of the known increased energy cost of locomotion in PwMS.