Modulation of response times in early-stage Parkinson's disease during emotional processing of embodied and non-embodied stimuli.

Valence (positive and negative) and content (embodied vs non-embodied) characteristics of visual stimuli have been shown to influence motor readiness, as tested with response time paradigms. Both embodiment and emotional processing are affected in Parkinson's disease (PD) due to basal ganglia dysfunction. Here we aimed to investigate, using a two-choice response time paradigm, motor readiness when processing embodied (emotional body language [EBL] and emotional facial expressions [FACS]) vs non-embodied (emotional scenes [IAPS]) stimuli with neutral, happy, and fearful content. We enrolled twenty-five patients with early-stage PD and twenty-five age matched healthy participants. Motor response during emotional processing was assessed by measuring response times (RTs) in a home-based, forced two-choice discrimination task where participants were asked to discriminate the emotional stimulus from the neutral one. Rating of valence and arousal was also performed. A clinical and neuropsychological evaluation was performed on PD patients. Results showed that RTs for PD patients were longer for all conditions compared to HC and that RTs were generally longer in both groups for EBL compared to FACS and IAPS, with the sole exception retrieved for PD, where in discriminating fearful stimuli, RTs for EBL were longer compared to FACS but not to IAPS. Furthermore, in PD only, when discriminating fearful respect to neutral stimuli, RTs were shorter when discriminating FACS compared to IAPS. This study shows that PD patients were faster in discriminating fearful embodied stimuli, allowing us to speculate on mechanisms involving an alternative, compensatory, emotional motor pathway for PD patients undergoing fear processing.

Neural oscillations modulation during working memory in pre-manifest and early Huntington's disease.

INTRODUCTION: We recently demonstrated specific spectral signatures associated with updating of memory information, working memory (WM) maintenance and readout, with relatively high spatial resolution by means of high-density electroencephalography (hdEEG). WM is impaired already in early symptomatic HD (early-HD) and in pre-manifest HD (pre-HD). The aim of this study was to test whether hdEEG coupled to source localization allows for the identification of neuronal oscillations in specific frequency bands in 16 pre-HD and early-HD during different phases of a WM task. METHODS: We examined modulation of neural oscillations by event-related synchronization and desynchronization (ERS/ERD) of θ, ß, gamma low, γLOW and γHIGH EEG bands in a-priori selected large fronto-parietal network, including the insula and the cerebellum. RESULTS: We found: (i) Reduced θ oscillations in HD with respect to controls in almost all the areas of the WM network during the update and readout phases; (ii) Modulation of ß oscillations, which increased during the maintenance phase of the WM task in both groups; (iii) correlation of γHIGH oscillations during WM task with disease burden score in HD patients. CONCLUSIONS: Our data show reduced phase-specific modulation of oscillations in pre-HD and early-HD, even in the presence of preserved dynamic of modulation. Particularly, reduced synchronization in the θ band in the areas of the WM network, consistent with abnormal long-range coordination of neuronal activity within this network, was found in update and readout phases in HD groups.

How Music Moves Us: Music-induced Emotion Influences Motor Learning.

Music is an important tool for the induction and regulation of emotion. Although learning a sequential motor behaviour is essential to normal motor function, to our knowledge, the role of music-induced emotion on motor learning has not been explored. Our experiment aimed to determine whether listening to different emotional music could influence motor sequence learning. We focused on two sub-components of motor sequence learning: the acquisition of the order of the elements in the sequence (the "what"), and the ability to carry out the sequence, combining the elements in a single, skilled action (the "how"). Twenty subjects performed a motor sequence-learning task with a digitizing tablet in three different experimental sessions. In each session they executed the task while listening to three different musical pieces, eliciting fearful, pleasant, and neutral mood. Eight targets were presented in a pre-set order and subjects were asked to learn the sequence while moving. Music-induced pleasure had an impact on movement kinematics with onset time and peak velocity decreasing and movement time increasing more with respect to neutral music session. Declarative learning, verbal recall of the sequence order, was improved under emotional manipulation, but only for fear-condition. Results suggest that music-induced emotion can influence both sub-components of motor learning in a different way. Music-induced pleasure may have improved motor components of sequence learning by means of increased striatal dopamine availability whereas music-induced fear may facilitate the recruitment of attentional circuits, thus acting on declarative knowledge of the sequence order.

One cue does not fit all: A systematic review with meta-analysis of the effectiveness of cueing on freezing of gait in Parkinson's disease.

The difficulty in assessing FOG and the variety of existing cues, hamper to determine which cueing modality should be applied and which FOG-related aspect should be targeted to reach personalized treatments for FOG. This systematic review aimed to highlight: i) whether cues could reduce FOG and improve FOG-related gait parameters, ii) which cues are the most effective, iii) whether medication state (ON-OFF) affects cues-related results. Thirty-three repeated measure design studies assessing cueing effectiveness were included and subdivided according to gait tasks (gait initiation, walking, turning) and to the medication state. Main results reveal that: preparatory phase of gait initiation benefit from visual and auditory cues; spatio-temporal parameters (e.g., step and stride length) are improved by visual cues during walking; turning time and step time variability are reduced by applying auditory and visual cues. Some findings on the potential benefits of cueing on FOG and FOG gait-related parameters were found. Questions remain about which are the best behavioral strategies according to FOG features and PD clinical characteristics.

Gender differences, environmental pressures, tumor characteristics, and death rate in a lung cancer cohort: a seven-years Bayesian survival analysis using cancer registry data from a contaminated area in Italy.

Introduction: In Taranto, Southern Italy, adverse impacts on the environment and human health due to industrial installations have been studied. In the literature, associations have been reported between gender, environmental factors, and lung cancer mortality in women and men. The aim of this study was to investigate the relationships between gender, residence in areas with high environmental pressures, bronchus/lung cancer characteristics, and death rate. Methods: Data from the Taranto Cancer Registry were used, including all women and men with invasive bronchus/lung cancer diagnosed between 1 January 2016 and 31 December 2020 and with follow-up to 31 December 2022. Bayesian mixed effects logistic and Cox regression models were fitted with the approach of integrated nested Laplace approximation, adjusting for patients and disease characteristics. Results: A total of 2,535 person-years were observed. Male gender was associated with a higher prevalence of histological grade 3 (OR 2.45, 95% CrI 1.35-4.43) and lung squamous-cell carcinoma (OR 3.04, 95% CrI 1.97-4.69). Variables associated with higher death rate were male gender (HR 1.24, 95% CrI 1.07-1.43), pathological/clinical stage II (HR 2.49, 95% CrI 1.63-3.79), III (HR 3.40, 95% CrI 2.33-4.97), and IV (HR 8.21, 95% CrI 5.95-11.34), histological grade 3 (HR 1.80, 95% CrI 1.25-2.59), lung squamous-cell carcinoma (HR 1.18, 95% CrI 1.00-1.39), and small-cell lung cancer (HR 1.62, 95% CrI 1.31-1.99). Variables associated with lower death rate were other-type lung cancer (HR 0.65, 95% CrI 0.44-0.95), high immune checkpoint ligand expression (HR 0.75, 95% CrI 0.59-0.95), lung localization (HR 0.73, 95% CrI 0.62-0.86), and left localization (HR 0.85, 95% CrI 0.75-0.95). Discussion: The results among patients with lung cancer did not show an association between residence in the contaminated site of national interest (SIN) and the prevalence of the above mentioned prognostic factors, nor between residence in SIN and death rate. The findings confirmed the independent prognostic values of different lung cancer characteristics. Even after adjusting for patients and disease characteristics, male gender appeared to be associated with a higher prevalence of poorly differentiated cancer and squamous-cell carcinoma, and with an increased death rate.

Environmental pressures, tumor characteristics, and death rate in a female breast cancer cohort: a seven-years Bayesian survival analysis using cancer registry data from a contaminated area in Italy.

Introduction: In Taranto, Southern Italy, adverse impacts on the environment and human health due to industrial installations have been studied. In the literature, few associations have been reported between environmental factors and breast cancer mortality in women. The aim of this study was to investigate the relationships between residence in areas with high environmental pressures, female breast cancer characteristics, and death rate. Methods: Data from the Taranto Cancer Registry were used, including all women with invasive breast cancer diagnosed between 01 January 2015 and 31 December 2020 and with follow-up to 31 December 2021. Bayesian mixed effects logistic and Cox regression models were fitted with the approach of integrated nested Laplace approximation, adjusting for patients and disease characteristics. Results: A total of 10,445 person-years were observed. Variables associated with higher death rate were residence in the contaminated site of national interest (SIN) (HR 1.22, 95% CrI 1.01-1.48), pathological/clinical stage III (HR 2.77, 95% CrI 1.93-3.97) and IV (HR 17.05, 95% CrI 11.94-24.34), histological grade 3 (HR 2.50, 95% CrI 1.20-5.23), Ki-67 proliferation index of 21-50% (HR 1.42, 95% CrI 1.10-1.83) and > 50% (HR 1.81, 95% CrI 1.29-2.55), and bilateral localization (HR 1.65, 95% CrI 1.01-2.68). Variables associated with lower death rate were estrogen and/or progesterone receptor positivity (HR 0.61, 95% CrI 0.45-0.81) and HER2/neu oncogene positivity (HR 0.59, 95% CrI 0.44-0.79). Discussion: The findings confirmed the independent prognostic values of different female breast cancer characteristics. Even after adjusting for patients and disease characteristics, residence in the SIN of Taranto appeared to be associated with an increased death rate.

Transcranial direct current stimulation alters sensorimotor modulation during cognitive representation of movement.

We recently demonstrated, by means of short latency afferent inhibition (SAI), that before an imagined movement, during the reaction time (RT), SAI decreases only in the movement-related muscle (sensorimotor modulation) and that a correlation exists between sensorimotor modulation and motor imagery (MI) ability. Excitatory anodal transcranial direct current stimulation (a-tDCS) on M1 could enhance the MI outcome; however, mechanisms of action are not completely known. Here, we assessed if a-tDCS on M1 prior to an MI task could affect sensorimotor modulation. Participants imagined abducting the index or little finger in response to an acoustic signal. SAI was evaluated from the first dorsal interosseus after the "go" signal, before the expected electromyographic (EMG) activity. Participants received 20-min 1.5 mA a-tDCS or sham-tDCS on M1 on two different days, in random order. Results showed that a-tDCS on M1 increases the sensorimotor modulation consisting of a weakening of SAI after the Go signal with respect to sham-tDCS, in the movement-related muscle right before the beginning of MI. These results suggest that a-tDCS on M1 further potentiate those circuits responsible for sensorimotor modulation in the RT phase of MI. Increased sensorimotor modulation during MI may be one of the mechanisms involved in MI improvement after a-tDCS over M1.

Sensorimotor inhibition during emotional processing.

Visual processing of emotional stimuli has been shown to engage complex cortical and subcortical networks, but it is still unclear how it affects sensorimotor integration processes. To fill this gap, here, we used a TMS protocol named short-latency afferent inhibition (SAI), capturing sensorimotor interactions, while healthy participants were observing emotional body language (EBL) and International Affective Picture System (IAPS) stimuli. Participants were presented with emotional (fear- and happiness-related) or non-emotional (neutral) EBL and IAPS stimuli while SAI was tested at 120 ms and 300 ms after pictures presentation. At the earlier time point (120 ms), we found that fear-related EBL and IAPS stimuli selectively enhanced SAI as indexed by the greater inhibitory effect of somatosensory afferents on motor excitability. Larger early SAI enhancement was associated with lower scores at the Behavioural Inhibition Scale (BIS). At the later time point (300 ms), we found a generalized SAI decrease for all kind of stimuli (fear, happiness or neutral). Because the SAI index reflects integrative activity of cholinergic sensorimotor circuits, our findings suggest greater sensitivity of such circuits during early (120 ms) processing of threat-related information. Moreover, the correlation with BIS score may suggest increased attention and sensory vigilance in participants with greater anxiety-related dispositions. In conclusion, the results of this study show that sensorimotor inhibition is rapidly enhanced while processing threatening stimuli and that SAI protocol might be a valuable option in evaluating emotional-motor interactions in physiological and pathological conditions.

Neural oscillations during motor imagery of complex gait: an HdEEG study.

The aim of this study was to investigate differences between usual and complex gait motor imagery (MI) task in healthy subjects using high-density electroencephalography (hdEEG) with a MI protocol. We characterized the spatial distribution of α- and ß-bands oscillations extracted from hdEEG signals recorded during MI of usual walking (UW) and walking by avoiding an obstacle (Dual-Task, DT). We applied a source localization algorithm to brain regions selected from a large cortical-subcortical network, and then we analyzed α and ß bands Event-Related Desynchronizations (ERDs). Nineteen healthy subjects visually imagined walking on a path with (DT) and without (UW) obstacles. Results showed in both gait MI tasks, α- and ß-band ERDs in a large cortical-subcortical network encompassing mostly frontal and parietal regions. In most of the regions, we found α- and ß-band ERDs in the DT compared with the UW condition. Finally, in the ß band, significant correlations emerged between ERDs and scores in imagery ability tests. Overall we detected MI gait-related α- and ß-band oscillations in cortical and subcortical areas and significant differences between UW and DT MI conditions. A better understanding of gait neural correlates may lead to a better knowledge of pathophysiology of gait disturbances in neurological diseases.

The effect of music-induced emotion on visual-spatial learning in people with Parkinson's disease: A pilot study.

INTRODUCTION: Emotional states have been shown to influence cognitive processes including visual-spatial learning. Parkinson's Disease (PD), besides manifesting with the cardinal motor symptoms, presents cognitive and affective disturbances. Here we aimed at investigating whether manipulation of the emotional state by means of music was able to influence the performance of a visual-spatial learning task in a group of PD participants. METHODS: Ten PD patients and 11 healthy elderly (ELD) were asked to perform a visual-spatial learning task while listening two musical pieces evoking a neutral emotion or fear. Targets were presented on a screen in a preset order over four blocks and subjects were asked to learn the sequence order by attending to the display. At the end of each block, participants were asked to verbally recall the sequence and a score was assigned (Verbal Score, VS). RESULTS: Analysis of variance-type statistic test on the VS disclosed a significant effect of Music and sequence Blocks (p = 0.01 and p < 0.001, respectively) and a significant interaction between Group and sequence Blocks. Sequence learning occurred across the training period in both groups, but PD patients were slower than ELD and at the end of the training period learning performance was worse in PD with respect to ELD. In PD patients, like in ELD, fear-inducing music has a detrimental effect on visual-spatial learning performances, which are slower and decreased. CONCLUSION: These findings confirm an impairment in visual-spatial learning in PD and indicates that the emotional state influences this learning ability similarly to healthy controls.

Motor Resonance Flexibility to Emotion-Enriched Context in Parkinson's Disease Patients.

In healthy people, motor resonance mechanisms are flexible to negative emotional contextual clues with greater motor resonance during the observation of a reach to grasp movement performed in an environment eliciting disgust. The link between emotion and motor control has become an interesting topic in Parkinson's disease (PD). Here, we aimed to study the response of the mirror neuron system, specifically motor resonance, to an emotion-enriched context in people with PD. Corticospinal excitability was recorded in a total of 44 participants, divided into two groups (23 PD patients and 21 healthy subjects). We recorded motor-evoked potentials from a muscle involved in the grasping movement while participants were watching the same reach-to-grasp movement embedded in surrounds with negative emotional valence, but different levels of arousal: sadness (low arousal) and disgust (high arousal). Basic motor resonance mechanisms were less efficient in PD than controls. Responsiveness to emotional contextual clues eliciting sadness was similar between PD and controls, whereas responsiveness to emotional contextual clues eliciting disgust was impaired in PD patients. Our findings show reduced motor resonance flexibility to the disgusting context, supporting the hypothesis that PD patients may have a deficit in "translating" an aversive motivational state into a physiologic response. The amygdala, which is implicated in the appraisal of fearful stimuli and response to threatening situations, might be implicated in this process.

Somatosensory inputs modulate the excitability of cerebellar-cortical interaction.

OBJECTIVE: Transcranial magnetic stimulation (TMS) delivered over the cerebellum 5-7 ms prior to a stimulus over the contralateral primary motor cortex (M1) reduces the excitability of M1 output, a phenomenon termed cerebellar brain inhibition (CBI). The cerebellum receives sensory information for adaptive motor coordination and motor planning. Here, we explored through TMS whether a peripheral electrical stimulus modulates CBI. METHODS: We studied the effect of right median nerve electrical stimulation (ES) on CBI from right cerebellum (conditioning stimulus, CS) to left M1 (test stimulus, TS) in 12 healthy subjects. The following ES-CS inter-stimulus intervals (ISIs) were tested: 25, 30 and 35 ms. CS-TS ISI was set at 5 ms. RESULTS: We found significantly weaker CBI when the ES was delivered 25 ms (p < 0.001) and 35 ms (p < 0.001) earlier the CS over the ipsilateral cerebellum and a trend for 30 ms ES-CS ISI (p = 0.07). CONCLUSIONS: We hypothesize that the activation of cerebellar interneurons together with intrinsic properties of Purkinje cells may be responsible of the decreased CBI when the peripheral stimulation preceded the cerebellar stimulation of 25 and 35 ms. SIGNIFICANCE: To test the interaction between somatosensory inputs and cerebello-cortical pathway may be important in a variety of motor tasks and neuropsychiatric disorders.

Pragmatic abilities in early Parkinson's disease.

Language impairment in Parkinson's disease (PD) has been investigated at different levels of linguistic skills. Only a few studies dealt with pragmatic abilities in PD, and these suggest an impairment of pragmatic skills, which might affect quality of life. However, previous studies enrolled patients with heterogeneous symptom severity. The goal of this study is twofold: first, to investigate whether pragmatic skills are compromised at the early stage of PD; second, to explore whether an early pragmatic impairment is explained by a decay of a specific cognitive function. We assessed pragmatic abilities (discourse production, comprehension of narratives, humour, and figurative language), and a cluster of cognitive functions (memory, verbal fluency, inhibition, shifting, and ToM) in a sample of early PD patients and a group of age-matched healthy controls. Early PD patients showed impaired general pragmatic skills (the ability to perform different pragmatic tasks in language production and comprehension), as well as a deficit in the production and comprehension individual scores. Our results suggest that good general cognitive skills (a good overall cognitive level) and high education support patients' pragmatic competence. Inhibitory processes have been found to predict patients' ability to understand figurative language, such as metaphors, and this might be related to frontal lobe dysfunctions.

Modulation of Response Times During Processing of Emotional Body Language.

The investigation of how humans perceive and respond to emotional signals conveyed by the human body has been for a long time secondary compared with the investigation of facial expressions and emotional scenes recognition. The aims of this behavioral study were to assess the ability to process emotional body postures and to test whether motor response is mainly driven by the emotional content of the picture or if it is influenced by motor resonance. Emotional body postures and scenes (IAPS) divided into three clusters (fear, happiness, and neutral) were shown to 25 healthy subjects (13 males, mean age ± SD: 22.3 ± 1.8 years) in a three-alternative forced choice task. Subjects were asked to recognize the emotional content of the pictures by pressing one of three keys as fast as possible in order to estimate response times (RTs). The rating of valence and arousal was also performed. We found shorter RTs for fearful body postures as compared with happy and neutral postures. In contrast, no differences across emotional categories were found for the IAPS stimuli. Analysis on valence and arousal and the subsequent item analysis showed an excellent reliability of the two sets of images used in the experiment. Our results show that fearful body postures are rapidly recognized and processed, probably thanks to the automatic activation of a series of central nervous system structures orchestrating the defensive threat reactions, strengthening and supporting previous neurophysiological and behavioral findings in body language processing.

Affective and cognitive theory of mind in patients with cervical dystonia with and without tremor.

Theory of mind (ToM) refers to an individual's ability to attribute mental states to predict and explain another person's behavior. It has been shown that patients with cervical dystonia (CD) present impaired ToM ability supporting the idea that CD is a network disorder. An emerging hypothesis is that different phenotypes of CD reflect distinct key nodes in the malfunctioning cerebral network. The aim of the present study was to investigate whether the presence of tremor as additional phenotypic feature of CD influences the ability to attribute a cognitive or emotional state to another person. We enrolled 35 patients with CD, 21 with tremor (CD-T) and 14 without tremor (CD-NT) and 47 age-matched healthy subjects (HS). The Emotion Attribution Task (EAT) was adopted to assess the affective ToM ability while the Advanced Test (AT) was used to investigate the cognitive ToM ability. Results showed that CD patients' performance was worse than HS in recognizing the emotional feelings expressed in the EAT situations, with no difference between CD-T and CD-NT. Regarding cognitive ToM, both CD-T and CD-NT performed worse than HS in the AT task. However, it also emerged that CD-T were more impaired in AT task than CD-NT. Our results indicate that both affective and cognitive aspects of ToM are impaired in CD and that cognitive ToM is more impaired in patients presenting tremor respect to those without. These findings support the hypothesis that the cerebral network responsible of motor and non-motor impairments is more widespread in CD-T than CD-NT.

Motor-Cognitive Treadmill Training With Virtual Reality in Parkinson's Disease: The Effect of Training Duration.

Treadmill training with virtual reality (TT + VR) has been shown to improve gait performance and to reduce fall risk in Parkinson's disease (PD). However, there is no consensus on the optimal training duration. This study is a sub-study of the V-TIME randomized clinical trial (NCT01732653). In this study, we explored the effect of the duration of training based on the motor-cognitive interaction on motor and cognitive performance and on fall risk in subjects with PD. Patients in Hoehn and Yahr stages II-III, aged between 40 and 70 years, were included. In total, 96 patients with PD were assigned to 6 or 12 weeks of TT + VR intervention, and 77 patients completed the full protocol. Outcome measures for gait and cognitive performance were assessed at baseline, immediately after training, and at 1- and 6-month follow-up. The incident rate of falls in the 6-month pre-intervention was compared with that in the 6-month post-intervention. Dual-task gait performance (gait speed, gait speed variability and stride length under cognitive dual task and obstacle negotiation, and the leading foot clearance in obstacle negotiation) improved similarly in both groups with gains sustained at 6-month follow-up. A higher decrease in fall rate and fear of falling were observed in participants assigned to the 12-week intervention than the 6-week intervention. Improvements in cognitive functions (i.e., executive functions, visuospatial ability, and attention) were seen only in participants enrolled in 12-week training up to 1-month follow-up but vanished at the 6-month evaluation. Our results suggest that a longer TT + VR training leads to greater improvements in cognitive functions especially those directly addressed by the virtual environment.

Consolidation and retention of motor skill after motor imagery training.

Complex motor tasks are learned through training which results in lasting improvement in sensorimotor performance and accuracy. Learning a motor skill is commonly attained via physical execution. However, research has shown that cognitive training, such as motor imagery (MI), effectively facilitates skill learning. Neurophysiological findings suggest that learning-induced plasticity in the human motor cortex, subserving consolidation and retention of motor skills, is stronger after movement execution (ME) than after MI training. Here, we designed an experimental task able to test for the fast and slow learning phases and for retention of motor skills for both MI and ME. We hypothesize that differences between MI and ME training would emerge in terms of reduced consolidation and retention of motor skills. Twenty-four young healthy subjects were divided into two groups, performing MI or ME training. Participants wore sensor-engineered gloves and their sensorimotor performance was assessed over a period of 15 days with 4-days training. We analysed the touch duration (TD), the inter-tapping interval (ITI), movement rate and accuracy. Results showed that (i) during the first phase of acquisition of motor skills, sensorimotor performance improved similarly in MI and ME groups; (ii) during the second learning phase movement rate increased more in ME than MI group and this difference was mainly driven by differences in the duration of TD; (iii) consolidation deficits with MI training reflected in impaired retention of the acquired skills, as TD and ITI were larger and movement rate was lower in the MI group with respect to the ME, till to 10 days after the last training session. Explicit component of motor learning, accuracy, was maintained in retention phase in both groups. Following our hypothesis, our findings show that MI training is as effective as ME within the first learning phase, but consolidation and retention of motor skills are less effective following MI training. This study highlights MI limitations and suggests option to enhance MI, as by providing an external sensory feedback.

Defective Human Motion Perception in Cervical Dystonia Correlates With Coexisting Tremor.

BACKGROUND: The ability to predict temporal outcome of body movement is abnormal in idiopathic dystonia and can be altered by cerebellar neuromodulation. Tremor in cervical dystonia might be associated with performance on motion perception tasks. METHODS: A total of 15 cervical dystonia patients with and 14 without tremor and 15 age-matched healthy participants estimated the termination of videos showing different movements (handwriting a sentence, ball reaching a target) after these were darkened at different time intervals. RESULTS: Cervical dystonia patients with tremor exhibited greater absolute timing error across all intervals of the hand motion task (group × task interaction effect, F2,41 = 4.57; P = 0.016). The percentage of responses in anticipation for both motion tasks did not differ across groups, suggesting lack of timing error directionality. CONCLUSIONS: Temporal processing of perceived motion in cervical dystonia is associated with the presence of tremor. Cortico-cerebellar network abnormalities in cervical dystonia might account for motion processing changes in these patients. © 2020 International Parkinson and Movement Disorder Society.

A Multimodal Training Modulates Short Afferent Inhibition and Improves Complex Walking in a Cohort of Faller Older Adults With an Increased Prevalence of Parkinson's Disease.

BACKGROUND: Falls are frequent in Parkinson's disease and aging. Impairments in the cholinergic-mediated attentional supervision of gait may contribute to increased fall risk, especially when obstacles challenge gait. Interventions combining motor-cognitive approaches have been shown to improve motor performance, cognitive skills, and falls number. Here, we hypothesized that an intervention simulating an attention-demanding walking condition could affect not only complex gait performance and fall risk but also short-latency afferent inhibition (SAI), as a marker of cholinergic activity. METHODS: Thirty-nine participants at falls risk (24 Parkinson's disease participants and 15 older adults) were recruited in a randomized controlled trial. Participants were assigned to treadmill training or treadmill training with non-immersive virtual reality intervention and trained three times a week for 6 weeks. SAI, a transcranial magnetic stimulation paradigm, was used to assess cholinergic activity. Gait kinematics was measured during usual walking and while negotiating physical obstacles. Transcranial magnetic stimulation and gait assessments were performed pre, post, and 6 months post-intervention. RESULTS: Treadmill training combined with non-immersive virtual reality induced an increase in inhibition of the SAI protocol on cortical excitability, improved obstacle negotiation performance, and induced a reduction of the number of falls compared with treadmill training. Furthermore, the more SAI increased after training, the more the obstacle negotiation performance improved and fall rate decreased. CONCLUSIONS: We provide evidence that an innovative rehabilitation approach targeting cognitive components of complex motor actions can induce changes in cortical cholinergic activity, as indexed by SAI, thereby enabling functional gait improvements.