A paradigm for emulating the early learning stage of handwriting: performance comparison between healthy controls and Parkinson's disease patients in drawing loop shapes (original) (raw)
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Proceedings of the 18th International Graphonomic Society Conference, 2017
Patients affected by Parkinson's disease (PD) show deficits in learning novel motor behaviors and executing previously acquired ones. We investigated whether the two phenomena are related, evaluating the hypothesis that PD patients have difficulties in executing fine movements (such as handwriting) acquired before the onset of the disease since they perform the task as they are executing it for the first time. We asked healthy subjects to write a sequence of 'l' on a digitizer tablet by drawing the loop of the letter in counterclockwise fashion (as they are used to do) and clockwise fashion (i.e. using a novel motor plan). We compared the kinematic features of the samples produced by healthy subjects to those measured in samples produced by PD patients. We focused the analysis on the ink trace segmentation points, which represent the starting/ending points of the elementary handwriting movements. Our results suggests that deficits observed in PD patients in executing both novel tasks (reduced learning performance compared to controls) and previously acquired task (disrupted kinematic features compared to controls) could be due to the same underlying deficit, i.e. impaired ability of PD patients to retain the motor plan associated to the task.
Parkinsons disease and the control of size and speed in handwriting
Neuropsychologia, 1999
This experiment investigated whether Parkinson|s disease "PD# patients experience problems in producing stroke size\ stroke duration or both\ in a handwriting task[ Thirteen PD patients and 04 elderly controls wrote four patterns of varying complexity on a digitizer tablet[ The participants were instructed to execute the writing movements] at a normal size and speed^as fast as possiblet wo times larger than normal^and two times larger and as fast as possible[ PD patients had no di.culty increasing speed while maintaining size and had no di.culty increasing size while maintaining speed[ However\ they showed signi_cantly smaller size increases in the two times larger condition as compared to the elderly controls[ The conditions were also simulated by a neural network model of normal and PD movement control that produced a stroke pattern that approximated the experimental data[ For the instructions used\ the results suggest that when patients scale speed\ they have no di.culty controlling force amplitude\ but when they scale stroke size\ they have a problem controlling force amplitude[ Thus\ PD patients may have reduced capability to maintain a given force level for the stroke time periods tested with the instructions[ Þ 0888 Elsevier Science Ltd[ All rights reserved[ Keywords] Force amplitude^Neural networks^Basal ganglia^Motor control^Wrist movements^Finger movements Corresponding author[ Tel[] ¦0 591 854 3607^fax] ¦0 591 854 7097^e!mail] vangemmertÝasu[edu
Control of stroke size, peak acceleration, and stroke duration in Parkinsonian handwriting
Human Movement Science, 1991
This experiment investigates movement coordination in Parkinson's disease (PD) subjects. Seventeen PD patients and 12 elderly control subjects performed several handwriting-like tasks on a digitizing writing tablet resting on top of a table in front of the subject. The writing patterns, in increasing order of coordination complexity, were repetitive back-and-forth movements in various orientations, circles and loops in clockwise and counterclockwise directions, and a complex writing pattern. The patterns were analyzed in terms of jerk normalized for duration and size per stroke. In the PD subjects, back-and-forth strokes, involving coordination of fingers and wrist, showed larger normalized jerk than strokes performed using either the wrist or the fingers alone. In the PD patients, wrist flexion (plus radial deviation) showed greater normalized jerk in comparison to wrist extension (plus ulnar deviation). The elderly control subjects showed no such effects as a function of coordination complexity. For both PD and elderly control subjects, looping patterns consisting of circles with a left-to-right forearm movement, did not show a systematic increase of normalized jerk. The same handwriting patterns were then simulated using a biologically inspired neural network model of the basal ganglia thalamocortical relations for a control and a mild PD subject. The network simulation was consistent with the observed experimental results, providing additional support that a reduced capability to coordinate wrist and finger movements may be caused by suboptimal functioning of the basal ganglia in PD. The results suggest that in PD patients fine motor control problems may be caused by a reduced capability to coordinate the fingers and wrist and by reduced control of wrist flexion. r 1997
Handwriting Rehabilitation in Parkinson Disease: A Pilot Study
Annals of rehabilitation medicine, 2015
To assess the utility of handwriting rehabilitation (HR) in Parkinson disease (PD) patients who experienced difficulties with handwriting and signing. Sixty PD patients were prospectively studied with graphological evaluations. Thirty PD patients were assigned to HR for 9 weeks. At the end of this training, all patients were evaluated again and results of basal vs. final evaluations were compared. At final evaluation, the group assigned to HR showed significantly larger amplitude of the first 'e' in the phrase, larger signature surface area, and superior margin. A trend of increase in letter size was also observed. Handwriting with progressively decreasing size of letters and ascending direction with respect to the horizontal were prominent findings in both groups of patients and they did not change after HR. Rehabilitation programs for handwriting problems in PD patients are likely to be helpful. Larger randomized studies are needed to confirm these results.
Handwriting with different effectors in individuals with Parkinson's disease
Parkinsonism & Related Disorders, 2020
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The influence of mental and motor load on handwriting movements in Parkinsonian patients
Acta Psychologica, 1998
This experiment tested the hypothesis that ParkinsonÕs disease (PD) patients are more vulnerable to a moderate level of secondary task load than elderly or young controls due to heightened variability in the motor system. PD patients, elderly, and young adults performed a handwriting task with dierent secondary tasks. The secondary task imposed motor load (i.e., speech) and/or a mental load (i.e., ignoring, repeating, or subtracting). The ®ndings showed that, in contrast to young and elderly controls, PD patients tended to increase MT, accumulated pause time, and normalized jerk when the secondary task consisted primarily of motor load. Furthermore, it was shown that PD patients did not reduce writing sizes as result of a high level of mental load which ®nding suggests that writing in an automated fashion does not result in micrographia. The results are discussed in relation to strategies imposed to contend with reduced signal-to-noise levels in the motor system. Ó 1998 Elsevier Science B.V. All rights reserved. 0001-6918/98/$ ± see front matter Ó 1998 Elsevier Science B.V. All rights reserved. PII: S 0 0 0 1 -6 9 1 8 ( 9 8 ) 0 0 0 3 2 -8
The effects of dual tasking on handwriting in patients with Parkinson’s disease
Neuroscience, 2014
Previous studies have shown that patients with Parkinson's disease (PD) experience extensive problems during dual tasking. Up to now, dual-task interference in PD has mainly been investigated in the context of gait research. However, the simultaneous performance of two different tasks is also a prerequisite to efficiently perform many other tasks in daily life, including upper limb tasks. To address this issue, this study investigated the effect of a secondary cognitive task on the performance of handwriting in patients with PD. Eighteen PD patients and 11 agematched controls performed a writing task involving the production of repetitive loops under single-and dual-task conditions. The secondary task consisted of counting high and low tones during writing. The writing tests were performed with two amplitudes (0.6 and 1.0 cm) using a writing tablet. Results showed that dual-task performance was affected in PD patients versus controls. Dual tasking reduced writing amplitude in PD patients, but not in healthy controls (p = 0.046). Patients' writing size was mainly reduced during the small amplitude condition (small amplitude p = 0.017; large amplitude p = 0.310). This suggests that the control of writing at small amplitudes requires more compensational brain-processing recourses in PD and is as such less automatic than writing at large amplitudes. In addition, there was a larger dual-task effect on the secondary task in PD patients than controls (p = 0.025). The writing tests on the writing tablet proved highly correlated to daily life writing as measured by the 'Systematic Screening of Handwriting Difficulties' test (SOS-test) and other manual dexterity tasks, particularly during dual-task conditions. Taken together, these results provide additional insights into the motor control of handwriting and the effects of dual tasking during upper limb movements in patients with PD.