Faculty Bibliography

BACKGROUND:Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has been shown to improve common symptoms of neurological disorders like depressed mood, fatigue, motor deficits and cognitive dysfunction. tDCS requires daily treatment sessions in order to be effective. We developed a remotely supervised tDCS (RS-tDCS) protocol for participants with multiple sclerosis (MS) to increase accessibility of tDCS, reducing clinician, patient, and caregiver burden. The goal of this protocol is to facilitate home use for larger trials with extended treatment periods. In this study we determine the generalizability of RS-tDCS paired with cognitive training (CT) by testing its feasibility in participants with Parkinson's disease (PD). METHODS:Following the methods in our MS protocol development, we enrolled sixteen participants (n = 12 male, n = 4 female; mean age 66 years) with PD to complete ten open-label sessions of RS-tDCS paired with CT (2.0 mA × 20 min) at home under the remote supervision of a trained study technician. Tolerability data were collected before, during, and after each individual session. Baseline and follow-up measures included symptom inventories (fatigue and sleep) and cognitive assessments. RESULTS:RS-tDCS was feasible and tolerable for patients with PD, with at-home access leading to high protocol compliance. Side effects were mostly limited to mild sensations of transient itching and burning under the electrode sites. Similar to prior finding sin MS, we found preliminary efficacy for improvement of fatigue and cognitive processing speed in PD. CONCLUSIONS:RS-tDCS paired with CT is feasible for participants with PD to receive at home treatment. Signals of benefit for reduced fatigue and improved cognitive processing speed are consistent across the PD and MS samples. RS-tDCS can be generalized to provide tDCS to a range of patients with neurologic disorders for at-home rehabilitation. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov Identifier: NCT02746705 . Registered April 21st 2016.

INTRODUCTION/BACKGROUND:Cognitive motor interference (CMI) is performance impairment due to simultaneuous task execution and is measured using the dual task cost (DTC). No pathological feature of MS has to date been associated with CMI. AIM/OBJECTIVE:To assess the relationship between brain volumes and CMI, as measured using the DTC, in a cross-sectional study. METHODS:A group of persons with MS (pwMS) and an age- and sex-matched healthy control (HC) group underwent 3D gait analysis during using the dual task paradigm. Brain volumes were measured on T1-weighted gradient echo scans using SIENAX software. The relationships between brain volumes and the DTCs of spatial temporal parameters were evaluated using Pearson correlation. A multiple regression model was used to evaluate the ability to predict the DTC of cadence based on brain volume and grey matter (GM) volume. RESULTS:value of 0.684 was found using GM and Z-score on the Stroop test as predictors of the DTC of cadence (p < 0.001). CONCLUSION/CONCLUSIONS:Brain atrophy, especially than in the GM, is a major determinant of DTC, although other pathological markers also contribute to CMI in patients with MS.

INTRODUCTION:Aging leads to poorer neuromuscular control that may impact mobility. However, the specific decades when these changes occur, and whether these time-based changes are sex-specific, are unclear. METHODS:Adults aged 20-82 years (N = 93, 51 females) walked six gait trials at their preferred speed over a 10-m platform. Electromyography (EMG) of the rectus femoris (RF), tibialis anterior (TA), and gastrocnemius lateralis (GL) were measured using wireless surface sensors. Root mean square (RMS) and within-cycle coefficient of variation (CV) values were calculated for several phases of gait. Mixed effect models were conducted to test for Age, Sex, Muscle, and interaction effects, covarying for gait speed and stride length. RESULTS:A significant Age × Sex × Muscle interaction on RMS at the mid-swing phase was found (p = .036), showing 4.2% higher RF RMS for males (β = 0.42, p = .008) and 3.3% higher GL RMS for females (β = 0.33, p = .038) with each of the three decades investigated. Significant Age × Muscle interactions on GL RMS were found at loading, mid-stance, and over the full gait cycle (ps < .05), with 2.0-4.3% higher values per decade (β = 0.20-0.43, ps < .05). There was generally higher CV with higher age at mid-swing and over the full gait cycle (significant Age effects, ps < .05). Females showed higher CV at loading, mid-stance, and terminal stance (significant Age × Sex effects, ps < .05). DISCUSSION/CONCLUSION:Results suggest sex-dependent influences of age on muscle recruitment during a few specific phases of gait, and sex-independent influences of age on the recruitment of the ankle musculature, and on the overall gait cycle. These influences may help explain overall increased instability and fall risk in older adults.

BACKGROUND:In clinical routine, upper limb motor disorders of people with Parkinson's disease are commonly assessed using scale- or timed tests, but such tools are not fully suitable for providing detailed information about their type and magnitude. To partly overcome these limitations, the present study aims to quantitatively investigate upper limb functional impairments through quantitative analysis of the "hand-to-mouth" task. METHODS:Twenty-five individuals with Parkinson's disease and 20 age-matched healthy individuals underwent a kinematic analysis of the hand-to-mouth task from which spatio-temporal and kinematic measures, including summary measures (Arm Variable Score and Arm Profile Score), were calculated and correlated with clinical scores (Hoehn & Yahr, H&Y and the Unified Parkinson Disease Rating Scale, UPDRS). FINDINGS:The "hand-to-mouth" movement is significantly altered in individuals with Parkinson's disease, especially in terms of reduced velocity, reduced range of motion of elbow flexion-extension and deviation from a physiologic pattern (Arm Profile Score 12.8° vs. 10.1° of unaffected, P = 0.002). Significant moderate correlations were found between movement duration and UPDRS-III (rho = 0.478, P = 0.001) and between the Arm Profile Score and H&Y (rho = 0.481, P = 0.024) and UPDRS-III (rho = 0.326, P = 0.001). INTERPRETATION:On the basis of such findings, we can state that the kinematic analysis of "hand-to-mouth" movement, and in particular the summary indexes, are suitable for easily representing upper limb movement alterations in people with Parkinson's disease, thus allowing the monitoring either of disease progression or effectiveness of pharmacologic and rehabilitative treatments.

BACKGROUND:The dual task paradigm (the simultaneous performance of motor and cognitive task) is used in a laboratory setting to evaluate walking impairments that affect patients' daily lives. Although promising, it is poorly standardized and neither the cognitive task nor the motor task have been validated in a matched healthy control group (HC) for multiple sclerosis (MS). OBJECTIVE:Our aim was to set up a standardized instrument to evaluate cognitive motor interference in MS using the interference test par excellence: the stroop colour word test (SCWT). METHODS:Patients with MS and HC underwent 3D gait analysis with a dual task protocol, using the SCWT as a cognitive task. Gait performance impairment during the dual task was evaluated by dual task cost (DTC). A MANOVA was used to verify the effect of status (MS, HC) on DTC, calculated for the spatiotemporal parameter of the gait. RESULTS:In MS, the DTC was higher for the following gait parameters: speed (p = .013), cadence (p = .004), stride time (p = .005) stance phase (p < .001), and swing phase duration (p = .032). CONCLUSION/CONCLUSIONS:DTC is present in MS and HC, but the motor cost in MS is higher. The present work provides a useful and validated basis for future studies about cognitive motor interference in MS.

PURPOSE/OBJECTIVE:This study aimed to characterize age-related changes in Timed Up and Go (TUG) sub-phases (i.e., sit to stand, walking and turning) quantitatively assessed using an inertial sensor in healthy older adults and to verify the degree of correlation between TUG parameters and muscular strength (assessed by handgrip strength, HGS) in the different age ranges. METHODS:This is a cross-sectional study performed on 125 healthy older adults aged over 65 years stratified in four groups (< 70 years, 71-75, 76-80, > 80) who underwent an instrumental TUG carried out using a wearable inertial sensor. In addition, participants were asked to carry out the HGS test to establish possible relationships between muscular strength and TUG features. RESULTS:The results show a general decline in all phases of TUG performance (albeit with some gender-related differences) which becomes significant after 75 years of age. Also, HGS was found to be systematically higher in men at any age group. Significant negative correlations between HGS and TUG phases times were found for both genders (men r = - 0.28 to - 0.50, women r = - 0.34 to - 0.60). However, when age groups were analyzed separately, such correlations are confirmed only in case of women aged < 70 years, while they vanish for most parameters in all other age groups. CONCLUSION/CONCLUSIONS:The findings obtained in the present study suggest that muscular strength might have a different relationship with functional mobility according to age and gender, and this should be considered when physical activity program or rehabilitation plans are planned.

OBJECTIVE:The purpose of this study was to assess the influence of trunk rotation (TR) on postural sway and spatial-temporal parameters of gait in children and early adolescents screened at school for the presence of scoliosis. METHODS:Two hundred and fifty-five individuals aged 9-14 (141 boys, 114 girls) underwent trunk rotation (TR) assessment by means of angle of trunk rotation (ATR) measurements performed with Bunnell's scoliometer. Participants with ATR ≥ 5° formed the TR group whose data were compared with those of a control group (CON) composed of individuals with ATR < 5° matched for age and anthropometric features. Postural sway was calculated on the basis of center of pressure (COP) time series acquired using a pressure plate. Spatial-temporal parameters of gait were derived from trunk accelerations collected by a single inertial sensor located in the low-back region. RESULTS:Sway area, sway path, COP velocities in medio-lateral (ML) and antero-posterior (AP) directions and COP displacements in ML direction were found significantly higher in girls with TR, while no differences between the TR and CON groups were detected in boys. Both boys and girls with TR exhibited gait patterns similar to those of their CON schoolmates. CONCLUSIONS:These findings suggest that even mild levels of TR may influence balance of female children and early adolescents screened for scoliosis, and thus early interventions including selective and task-oriented exercises appear advisable. In contrast, TR does not appear to influence gait, but further investigations are required to clarify whether different ATR cut-offs may reveal alterations of spatial-temporal parameters.