Faculty Bibliography

BACKGROUND:In people with multiple sclerosis (pwMS), disability is generally assessed on the basis of ambulation abilities, whereas upper limb motor dysfunctions are less frequently considered. Nevertheless, they can severely affect the quality of life of pwMS. To date, it remains mostly unknown whether a relationship exists between upper and lower limb impairments. AIM/OBJECTIVE:To investigate the existence of a relationship between upper and lower limb impairments in pwMS based on two fundamental motor tasks, namely walking and hand-to-mouth (HTM) movement. METHODS:Twenty-eight pwMS with Expanded Disability Status Scale (EDSS) scores in the range of 1-6, and 21 healthy controls (HC) underwent a kinematic analysis of gait and HTM movement performed with a motion capture system. The spatiotemporal parameters for the two tasks were calculated and correlated using Spearman's rank correlation coefficients. RESULTS:< 0.05). CONCLUSIONS:Both upper and lower limb motor abilities in pwMS worsen as disability increases. Nevertheless, their relationship is only moderate. This finding emphasizes the need for specific tests to quantify disability considering the overall motor function in pwMS.

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.