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Objective To understand whether lower limb asymmetry in chronic stroke is related to paretic motor impairment or impaired interlimb coordination. Methods Stroke and control participants performed conventional, unilateral, and bilateral uncoupled pedaling. During uncoupled pedaling, the pedals were mechanically disconnected. Paretic mechanical work was measured during conventional pedaling. Pedaling velocity and muscle activity were compared across conditions and groups. Relative limb phasing was examined during uncoupled pedaling. Results During conventional pedaling, EMG and mechanical work were lower in the paretic than the non-paretic limb (asymmetry). During unilateral pedaling with the paretic limb, muscle activity was larger, but velocity was slower and more variable than during conventional pedaling (evidence of paretic motor impairment). During uncoupled pedaling, muscle activity increased further, but velocity was slower and more variable than in other conditions (evidence of impaired interlimb coordination). Relative limb phasing was impaired in stroke participants. Regression analysis suggested that interlimb coordination may be a stronger predictor of asymmetry than paretic motor impairment. Conclusions Paretic motor impairment and impaired interlimb coordination may contribute to asymmetry during pedaling after stroke. Significance Rehabilitation that addresses paretic motor impairment and impaired interlimb coordination may improve symmetry and maximize improvement.

Objective To investigate the relationship between Motor Unit Number Index (MUNIX) and functional scales in patients with anti-Myelin Associated Glycoprotein (MAG) neuropathy and to know if MUNIX is modify after rituximab (RTX) therapy. Methods 17 patients were enrolled, of whom 6 were prospectively evaluated during one year after RTX treatment. MUNIX technique was assessed in abductor digiti mini (ADM), abductor pollicis brevi (APB) and tibialis anterior (TA) muscles. MUNIX sum score was calculated by adding the results of ADM, APB and TA muscles. Results MUNIX sum score was correlated with overall neuropathy limitation scale (ONLS) ( r =−0.55, p =0.02), grip strength in dominant hand ( r =0.63, p =0.01) MRC testing ( r =0.71, p r =0.71, p =0.001). Twelve months after RTX, four patients improved their disability measured on the ONLS score, five patients had improved MUNIX sum score with a median increase of 37% compared to initial evaluation. Conclusions MUNIX is related to motor impairment and disability in anti-MAG neuropathy and MUNIX is modified after immunosuppressive treatment. Significance Considering its advantages, MUNIX may be a suitable test to evaluate anti-MAG neuropathy in clinical trials.

Objective Freezing of gait (FOG) is a locomotor disturbance in Parkinson disease (PD) related to impaired motor automaticity. In this study, we investigated the impact of freezing on automaticity in the oculomotor system using an anti-saccade paradigm. Methods Subjects with PD with (PD–FOG, n =13) and without (PD–NON, n =13) FOG, and healthy age-matched controls (CTRL, n =12) completed automatic pro-saccades and non-automatic anti-saccades. Primary outcomes were saccade latency, velocity, and gain. Results PD–FOG (pro-saccade latency=271ms, anti-saccade latency=412ms) were slower to execute both types of saccades compared to PD–NON (253ms, 330ms) and CTRL (246ms, 327ms). Saccade velocity and gain variability was also increased in PD–FOG. Conclusions Saccade performance was affected in PD–FOG for both types of saccades, indicating differences in automaticity and control in the oculomotor system related to freezing. Significance These results and others show that FOG impacts non-gait motor functions, suggesting global motor impairment in PD–FOG.

Objective Motor dysfunction in Complex Regional Pain Syndrome (CRPS) has been associated with bilateral changes in central motor processing, suggesting abnormal coupling between the affected and unaffected limb. We evaluated the occurrence of involuntary muscle activity in a limb during voluntary movements of the contralateral limb (i.e., mirror activity) in unilaterally affected patients to examine disinhibition of contralateral motor activity in CRPS. Methods Mirror activity was examined during unimanual rhythmic flexion–extension movements of the wrist through in-depth analysis of electromyography recordings from the passive arm in 20 CRPS patients and 40 controls. Results The number of mirror-epochs was comparable for both arms in both CRPS patients and controls. Mirror-epochs in the affected arm of patients were comparable to those in controls. Mirror-epochs in the unaffected arm were shorter and showed less resemblance (in terms of rhythm and timing) to activity of the homologous muscle in the moving arm compared to mirror-epochs in controls. Conclusions No evidence for disinhibition of contralateral motor activity was found during unimanual movement. Significance Although motor dysfunction in CRPS has been associated with bilateral changes in cortical motor processing, the present findings argue against disinhibition of interhemispheric projections to homologous muscles in the contralateral limb during unimanual movement.

Objective: To investigate whether error-related potentials can be used to increase information transfer rate of a P3 brain-computer interface (BCI) in healthy and motor-impaired individuals. Methods: Extraction and classication of the error-related potential was performed oine on data recorded from 6 amyotrophic lateral sclerosis (ALS) patients. An online study with 17 healthy and 6 motor impaired participants followed, using a modied P3 speller to provide explicit feedback of spelled letters. On recognition of error-related potentials, the interface informed users that the incorrect letter was automatically deleted. Results: The oine cross-validation estimate of P3 speller data of 6 ALS patients increased bit rate by 0.44 bit/trial. During online copy spelling, the participants increased their bit rate by 0.52 bit/trial with the error correction system (ECS). Some participants performed free spelling and were able to increase their bit rate. Finally, we demonstrated that healthy participants could increase their bit rate by using a classier pre-trained on other users’ data. Conclusions: Error-related potentials as a secondary source of information can be used to increase overall bit rate in a P3 BCI. Signicance: The method should be made available to any patient using the P3 BCI for communication.

This study determined whether recovery of upper limb position control using submaximal force production correlates with an improvement in functional arm impairment during early recovery from stroke.Ten consecutive inpatients were recruited from a stroke unit. Each patient was in early recovery (8 weeks post-lesion) from their first ever stroke. Evaluations of submaximal continuous force production and position control, maximal force production at the shoulder and a clinical outcome measure of motor impairment (Fugl-Meyer score; FM) were performed 20 days post-stroke as a baseline and then once a week for the following four weeks.Submaximal force production and its modulation during a position-holding task improved in early recovery after stroke, whereas maximal force production did not. Better modulation of submaximal force production enabled improved arm position control which was significantly correlated to the changes in FM score of motor impairment during recovery.This study demonstrated that improvement in submaximal force modulation can operate as a mechanism enabling better motor behaviour such as arm position control during early recovery from a stroke.Future rehabilitation strategies may benefit from adding submaximal force development and modulation to early interventions after stroke.

The aim was to determine whether diffusion kurtosis imaging (DKI-MRI) could detect changes in dorsal motor nucleus of vagus (DMV) in mice who received chronic administration of rotenone. This may help in early diagnosis of patients with Parkinson’s disease. Mice received vehicle (VEH) or rotenone (ROT) intragastrically for 4 months. DKI scanning was performed at 2, 3 and 4 months. ROI analysis was used to compare kurtosis and diffusivity parameters in GM regions. WM tracts were investigated using the tract-based spatial statistics. We found significant increase in mean kurtosis in DMV in the ROT group at 2 months. At 3 months we found increase in kurtosis and decrease in diffusivity in almost all regions of interest, showing once the pathology crosses the DMV it spreads throughout the brain. At 4 months all the changes vanished. ROT group showed significant motor impairment at 4 months. At 2 months the DKI parameters may improve the early diagnosis of PD by showing increase in mean kurtosis in the DMV. This may help in monitoring and developing neuroprotective therapy. On the other hand, the lack of the DKI signal changes between ROT and VEH groups at the 4 months probably reflects the brain atrophy.

This study investigated the combined effects of anodal tDCS and intensive motor training (MT) vs. sham stimulation with MT (control intervention) on grip strength, motor performance and functional use of the affected arm. A total of 14 patients were randomly assigned to active stimulation treatment or a control intervention in a double-blinded, sham-controlled, parallel design. Each group received intensive MT for 45 min/day, 5 days/week, for 2 weeks, preceded by 20 min of 2 mA anodal tDCS over the ipsilesional M1 vs. sham tDCS. The Jebsen Taylor Hand Function Test (JTHFT), hand dynamometer and Fugl-Meyer Assesment (FMA) are tested at baseline, and after each intervention at Day 1, Day 10 and Day 30. The time required to complete the JTHFT between affected and non-affected hand was 81.65 ± 29.61 and 33.00 ± 3.59, respectively. At T 2 significant time shortening for total JTHFT (28.69 ± 18.51) was observed in affected hand. During follow up evaluation at T 3 preiously observed improvements were sustained. Considering grip strength and FMA score, we did not found any relevant changes. Our findings suggest that functional ability consequences of chronic hand motor impairment among stroke survivors, could be improved with anodal tDCS over ipsilesional cortex when coupled with intensive motor training.