Handwriting training in Parkinson's disease: A trade-off between size, speed and fluency

Sensorimotor functioning changes in response to global exercise versus handwriting upper limb exercise training in Parkinson's disease, results from a phase II randomised controlled trial

INTRODUCTION

People with Parkinson's disease (PwPD) present motor alterations which can impact daily life tasks that require speed and/or accuracy of movement.

OBJECTIVE

A sub analysis of NCT01439022, aiming to estimate the extent to which two different exercise training protocols (global and handwriting upper limb exercise training) impact reaction time, travel speed, and accuracy in PwPD.

METHODS

Seventy PwPD, right-side dominant were randomised 1:1 into two six-month training protocol groups; 35 PwPD performed global exercise training and 35 performed specific training (handwriting upper limb exercise movements). Assessments of speed-accuracy and trade-off were carried out at baseline, after 3 and 6 months of training, and at a 12-month follow-up. The current study used data from a previous publication of a randomised controlled trial that included a 6-month self-managed community exercise programme for PwPD. For the present study we included only the participants who completed the Fitts' task during the baseline assessment.

RESULTS

In the upper limb assessments, no main effects were found for the number of touches, but the exercise group showed a marginal increase over time on the left side. Error averages on the left side decreased significantly for the exercise group from baseline to 6 and 12 months. The exercise group also presented a lower Error CoV and the Reaction Time CoV increased on the right side. Significant findings for Fitts r on the left side indicated lower values for the exercise group, with improvements continuing at 12 months.

CONCLUSION

We report the potential of global exercise interventions to facilitate improvements in reaction time and travel speed, as well as other motor control metrics, with lasting effects at 12 months, particularly on the non-dominant side.

Intelligent Human-Computer Interaction: Combined Wrist and Forearm Myoelectric Signals for Handwriting Recognition

Recent studies have highlighted the possibility of using surface electromyographic (EMG) signals to develop human-computer interfaces that are also able to recognize complex motor tasks involving the hand as the handwriting of digits. However, the automatic recognition of words from EMG information has not yet been studied. The aim of this study is to investigate the feasibility of using combined forearm and wrist EMG probes for solving the handwriting recognition problem of 30 words with consolidated machine-learning techniques and aggregating state-of-the-art features extracted in the time and frequency domains. Six healthy subjects, three females and three males aged between 25 and 40 years, were recruited for the study. Two tests in pattern recognition were conducted to assess the possibility of classifying fine hand movements through EMG signals. The first test was designed to assess the feasibility of using consolidated myoelectric control technology with shallow machine-learning methods in the field of handwriting detection. The second test was implemented to assess if specific feature extraction schemes can guarantee high performances with limited complexity of the processing pipeline. Among support vector machine, linear discriminant analysis, and K-nearest neighbours (KNN), the last one showed the best classification performances in the 30-word classification problem, with a mean accuracy of 95% and 85% when using all the features and a specific feature set known as TDAR, respectively. The obtained results confirmed the validity of using combined wrist and forearm EMG data for intelligent handwriting recognition through pattern recognition approaches in real scenarios.

Rehabilitative interventions for impaired handwriting in people with Parkinson's disease: a scoping review

BACKGROUND

People with Parkinson's disease (PD) often complain about handwriting difficulties. Currently, there is no consensus on the rehabilitative treatment and outcome measures for handwriting rehabilitation in PD.

OBJECTIVES

This study aims to investigate evidence on handwriting rehabilitation in people with PD, examining characteristics of interventions and outcomes.

METHODS

A scoping review was conducted according to Arksey and O'Malley's framework and PRISMA-ScR List. We searched electronic databases of PubMed, Physiotherapy Evidence Database, Cochrane Central Register of Controlled Trials, and Embase since inception to January 2023. We included interventional studies assessing the effects of structured rehabilitation programs for impaired handwriting in people with PD. Two reviewers independently selected studies, extracted data, and assessed the risk of bias using the Cochrane Collaboration's tool for assessing Risk of Bias version 2 or the Risk Of Bias In Non-randomized Studies. We performed a narrative analysis on training characteristics and assessed outcomes.

RESULTS

We included eight studies. The risk of bias was generally high. Either handwriting-specific or handwriting-non-specific trainings were proposed, and most studies provided a home-based training. Handwriting-specific training improved writing amplitude while handwriting-non-specific trainings, such as resistance and stretching/relaxation programs, resulted in increased writing speed.

CONCLUSIONS

The current knowledge is based on few and heterogeneous studies with high risk of bias. Handwriting-specific training might show potential benefits on handwriting in people with PD. Further high-quality randomized controlled trials are needed to reveal the effect of handwriting training in people with PD on standardized outcome measures. Handwriting-specific training could be combined to resistance training and stretching, which seemed to influence writing performance.

Transcranial direct current stimulation enhances motor learning in Parkinson's disease: a randomized controlled trial

Writing training has shown clinical benefits in Parkinson's disease (PD), albeit with limited retention and insufficient transfer effects. It is still unknown whether anodal transcranial direct current stimulation (atDCS) can boost consolidation in PD and how this interacts with medication. To investigate the effects of training + atDCS versus training + sham stimulation on consolidation of writing skills when ON and OFF medication. Second, to examine the intervention effects on cortical excitability. In this randomized sham-controlled double-blind study, patients underwent writing training (one session) with atDCS (N = 20) or sham (N = 19) over the primary motor cortex. Training was aimed at optimizing amplitude and assessed during online practice, pre- and post-training, after 24-h retention and after continued learning (second session) when ON and OFF medication (interspersed by 2 months). The primary outcome was writing amplitude at retention. Cortical excitability and inhibition were assessed pre- and post-training. Training + atDCS but not training + sham improved writing amplitudes at retention in the ON state (p = 0.017, g = 0.75). Transfer to other writing tasks was enhanced by atDCS in both medication states (g between 0.72 and 0.87). Also, training + atDCS improved continued learning. However, no online effects were found during practice and when writing with a dual task. A post-training increase in cortical inhibition was found in the training + atDCS group (p = 0.039) but not in the sham group, irrespective of medication. We showed that applying atDCS during writing training boosted most but not all consolidation outcomes in PD. We speculate that atDCS together with medication modulates motor learning consolidation via inhibitory processes ( https://osf.io/gk5q8/ , 2018-07-17).

Smoothness of movement in idiopathic cervical dystonia

Smoothness (i.e. non-intermittency) of movement is a clinically important property of the voluntary movement with accuracy and proper speed. Resting head position and head voluntary movements are impaired in cervical dystonia. The current work aims to evaluate if the smoothness of voluntary head rotations is reduced in this disease. Twenty-six cervical dystonia patients and 26 controls completed rightward and leftward head rotations. Patients’ movements were differentiated into “towards-dystonia” (rotation accentuated the torticollis) and “away-dystonia”. Smoothness was quantified by the angular jerk and arc length of the spectrum of angular speed (i.e. SPARC, arbitrary units). Movement amplitude (mean, 95% CI) on the horizontal plane was larger in controls (63.8°, 58.3°–69.2°) than patients when moving towards-dystonia (52.8°, 46.3°–59.4°; P = 0.006). Controls’ movements (49.4°/s, 41.9–56.9°/s) were faster than movements towards-dystonia (31.6°/s, 25.2–37.9°/s; P < 0.001) and away-dystonia (29.2°/s, 22.9–35.5°/s; P < 0.001). After taking into account the different amplitude and speed, SPARC-derived (but not jerk-derived) indices showed reduced smoothness in patients rotating away-dystonia (1.48, 1.35–1.61) compared to controls (1.88, 1.72–2.03; P < 0.001). Poor smoothness is a motor disturbance independent of movement amplitude and speed in cervical dystonia. Therefore, it should be assessed when evaluating this disease, its progression, and treatments.

New Recovery Strategies in Motor and Cognitive Functions, before, during and after Home-Confinement COVID-19, for Healthy Adults and Patients with Neurodegenerative Diseases: Review

Distancing and confinement at home during the Coronavirus Disease 2019 (COVID-19) outbreak has led to worsening of motor and cognitive functions, both for healthy adults and for patients with neurodegenerative diseases. The decrease in physical activity, the cessation of the intervention of the recovery and the social distance imposed by the lockdown, has had a negative impact on the physical and mental health, quality of life, daily activities, as well as on the behavioral attitudes of the diet. The purpose of this paper was to evaluate the impact of decreasing physical activity and the affected emotional status in healthy adults and patients with neurodegenerative diseases in conditions imposed by the stay at home mandate of COVID-19, along with new interventions, such as telemedicine and telerehabilitation. These interventions include online surveys carried out in multi-languages, semi-structured interviews, intervention smartphones and interventions through online platforms, for instance: Google, WhatsApp, Twitter, ResearchGate, Facebook and LinkedIn. For this study, we selected original papers that were intensively processed using characteristics co-related with physical activity, mental wellbeing, sleep quality, good eating behavior and healthy lifestyle. By searching the last two years of literature, our review presents and demonstrates the benefit of online technological interventions in lockdown, which promote physical exercise patterns and rehabilitation techniques, for healthy adults and patients with neurodegenerative diseases, and the need to develop new strategic directions and governmental measures, designed procedures and health services, which are expected to improve the quality of life, the progress of physical and cognitive functions, mental health and wellbeing for all.

Action observation and imitation in Parkinson's disease: The influence of biological and non-biological stimuli

Action observation and imitation have been found to influence movement in people with Parkinson's disease (PD), but simple visual stimuli can also guide their movement. To investigate whether action observation may provide a more effective stimulus than other visual cues, the present study examined the effects of observing human pointing movements and simple visual stimuli on hand kinematics and eye movements in people with mild to moderate PD and age-matched controls. In Experiment 1, participants observed videos of movement sequences between horizontal positions, depicted by a simple cue with or without a moving human hand, then imitated the sequence either without further visual input (consecutive task) or while watching the video again (concurrent task). Modulation of movement duration, in accordance with changes in the observed stimulus, increased when the simple cue was accompanied by the hand and in the concurrent task, whereas modulation of horizontal amplitude was greater with the simple cue alone and in the consecutive task. Experiment 2 compared imitation of kinematically-matched dynamic biological (human hand) and non-biological (shape) stimuli, which moved with a high or low vertical trajectory. Both groups exhibited greater modulation for the hand than the shape, and differences in eye movements suggested closer tracking of the hand. Despite producing slower and smaller movements overall, the PD group showed a similar pattern of imitation to controls across tasks and conditions. The findings demonstrate that observing human action influences aspects of movement such as duration or trajectory more strongly than non-biological stimuli, particularly during concurrent imitation.

Functional Recovery in Parkinson's Disease: Current State and Future Perspective

Parkinson’s disease (PD) is one of the most frequent neurodegenerative disorders, affecting not only the motor function but also limiting the autonomy of affected people. In the last decade, the physical exercises of different intensities carried out by kinetic therapeutic activities, by robotic technologies or with the participation of sensory cues, have become increasingly appreciated in the management of Parkinson’s disease impairments. The aim of this paper was to evaluate the impact of physical exercises with and without physical devices on the motor and cognitive variables of PD patients. In order to achieve our objectives, we performed a systematic review of available original articles based on the impact of kinetic therapeutic activity. Through the search strategy, we selected original papers that were laboriously processed using characteristics related to physical therapy, or the tools used in physiological and psychological rehabilitation strategies for PD patients. In this study, we presented the most current intervention techniques in the rehabilitation programs of patients with Parkinson’s disease, namely the use of assisted devices, virtual imagery or the performing of physical therapies that have the capacity to improve walking deficits, tremor and bradykinesia, to reduce freezing episodes of gait and postural instability, or to improve motor and cognitive functions.

Levodopa improves handwriting and instrumental tasks in previously treated patients with Parkinson's disease

Motor symptoms in patients with Parkinson's disease may be determined with instrumental tests and rating procedures. Their outcomes reflect the functioning and the impairment of the individual patient when patients are tested off and on dopamine substituting drugs. Objectives were to investigate whether the execution speed of a handwriting task, instrumentally assessed fine motor behavior, and rating scores improve after soluble levodopa application. 38 right-handed patients were taken off their regular drug therapy for at least 12 h before scoring, handwriting, and performance of instrumental devices before and 1 h after 100 mg levodopa intake. The outcomes of all performed procedures improved. The easy-to-perform handwriting task and the instrumental tests demand for fast and precise execution of movement sequences with considerable cognitive load in the domains' attention and concentration. These investigations may serve as additional tools for the testing of the dopaminergic response.

tDCS-Enhanced Consolidation of Writing Skills and Its Associations With Cortical Excitability in Parkinson Disease: A Pilot Study

Background. Learning processes of writing skills involve the re-engagement of previously established motor programs affected by Parkinson disease (PD). To counteract the known problems with consolidation in PD, transcranial direct current stimulation (tDCS) could be imperative to achieve a lasting regeneration of habitual motor skills. Objective. To examine tDCS-enhanced learning of writing and explore alterations in cortical excitability after stimulation in PD compared with healthy controls (HCs). Methods. Ten patients and 10 HCs received 2 training sessions combined with 20 minutes of 1-mA anodal tDCS or sham on the left primary motor cortex in a randomized crossover design. Writing skills on a tablet and paper were assessed at baseline, after training, and after 1 week of follow-up. Before and immediately after the intervention, cortical excitability and inhibition were measured during rest and activity. Results. Writing amplitude and velocity improved when practice was tDCS supplemented compared with sham in PD. Benefits were sustained at retention for trained and untrained tasks on the tablet as well as for writing on paper. No improvements were found for HCs. Reduced resting motor thresholds after tDCS indicated tDCS-enhanced cortical excitability. Additionally, increments in motor-evoked potential amplitudes correlated with improved writing in PD, whereas HCs showed the opposite pattern. Conclusion. Our results endorse the usefulness of tDCS-boosted learning in PD, at least when applied to improving writing capacity. Although further confirmatory studies are needed, these novel findings are striking because tDCS-mediated consolidation was found for learning a motor task directly affected by PD.

The nature of bradykinesia in schizophrenia treated with antipsychotics

Recognizing drug-induced parkinsonian bradykinesia in psychosis patients can be challenging due to overlapping presentation with psychomotor slowing associated with depression, negative symptoms, or cognitive disturbances. In this study, we apply prior findings on the pathophysiology of bradykinesia in Parkinson's disease to gain an understanding of motor slowing in psychosis patients. Handwriting movements from 57 healthy participants and 70 psychosis patients were recorded on a digitizing tablet. Temporal and kinematic features were extracted from handwritten loops and circles. An independent objective measure based on peak velocity for circles written at maximum speed was used to classify patients as bradykinetic. Using a statistical cut-point derived from normative data, 64% of the patients met criterion for bradykinesia compared with 46% using a conventional observer-based severity rating scale. Bradykinetic patients produced handwriting movements with longer stroke durations, smaller amplitudes and lower peak velocities compared with non-bradykinetic patients. Thirty-six percent of the pen strokes produced by the bradykinetic patients were non-ballistic compare with 20% for the non-bradykinetic patients. The proportion of nonballistic movements observed in handwriting was unrelated to current antipsychotic dose, severity of negative psychosis or depression. The ease-of-use and standardization of a tablet-based approach to quantifying parkinsonian bradykinesia can aid in diagnosing parkinsonian bradykinesia in patients treated with antipsychotics.

A Smartphone Application for Automated Decision Support in Cognitive Task Based Evaluation of Central Nervous System Motor Disorders

BACKGROUND AND OBJECTIVE

New technology enables constant boost to the powers of mobile devices, which in the previous years have transformed from simple mobile phones to smart phones. Computational powers of these electronics enable actions that previously were possible only for computers. By the use of special applications, we may benefit from sensors and multimedia capabilities of operating systems. Therefore, a new era for devoted implementations opens, in which a smart application can take a role of computing system to estimate the symptoms of diseases by evaluating signals coming from a human body.

METHODS

We propose a model of an application implemented for mobile android systems, which can be used for examination of central nervous system motor disorders occurring in patients suffering from Huntington (HD), Alzheimer, or Parkinson diseases. In particular, the model tracks tremors (involuntary movements), and cognitive (memory loss or dementia) impairments using touch and visual stimulus modalities. The proposed model interprets the symptoms from human bodies that indicate one of the diseases of the nervous system. Pre-processing of collected data for feature extraction is executed on a mobile device by using core functionality and methods provided in android's application programming interface. The information is evaluated by a back-propagation neural network classifier and the result is presented to the end user. The system is able to contact medical supervision and provide an assistance from the clinic.

RESULTS

The system uses a collected dataset of 1928 records, taken from 11 HD patients and 11 healthy persons in Lithuania, to gather statistics about examinations and presents the results as medical evaluation with prediction on the state of health. The accuracy of recognition of early, prodromal symptoms for central nervous system motor disorders is 86.4% (F-measure 0.859). The app (available on Google Play) is easy to use and is efficient tool for decision support in medical examinations.

CONCLUSIONS

The use of intelligent apps which can help to evaluate neurodegenerative disorders is an important enhancement to medical diagnosis. The developed smartphone app supports the doctor with additional results that are easy to compare with other examinations. This kind of examination is a nice change from classic stereotypes, especially for younger age patients, who are used to various aspects of information technology.

Identification and Monitoring of Parkinson’s Disease Dysgraphia Based on Fractional-Order Derivatives of Online Handwriting

Parkinson’s disease dysgraphia affects the majority of Parkinson’s disease (PD) patients and is the result of handwriting abnormalities mainly caused by motor dysfunctions. Several effective approaches to quantitative PD dysgraphia analysis, such as online handwriting processing, have been utilized. In this study, we aim to deeply explore the impact of advanced online handwriting parameterization based on fractional-order derivatives (FD) on the PD dysgraphia diagnosis and its monitoring. For this purpose, we used 33 PD patients and 36 healthy controls from the PaHaW (PD handwriting database). Partial correlation analysis (Spearman’s and Pearson’s) was performed to investigate the relationship between the newly designed features and patients’ clinical data. Next, the discrimination power of the FD features was evaluated by a binary classification analysis. Finally, regression models were trained to explore the new features’ ability to assess the progress and severity of PD. These results were compared to a baseline, which is based on conventional online handwriting features. In comparison with the conventional parameters, the FD handwriting features correlated more significantly with the patients’ clinical characteristics and provided a more accurate assessment of PD severity (error around 12%). On the other hand, the highest classification accuracy (ACC = 97.14%) was obtained by the conventional parameters. The results of this study suggest that utilization of FD in combination with properly selected tasks (continuous and/or repetitive, such as the Archimedean spiral) could improve computerized PD severity assessment.