The influence of mental and motor load on handwriting movements in Parkinsonian patients (original) (raw)
Related papers
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.
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
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.
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 with different effectors in individuals with Parkinson's disease
Parkinsonism & Related Disorders, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Parkinsonian Patients Reduce Their Stroke Size with Increased Processing Demands
Brain and Cognition, 2001
Parkinson's disease (PD) patients often show reductions in writing size (micrographia) as the length of the text they produce increases. The cause for these reductions in stroke size are not well understood. Reductions in stroke size could be associated with either concurrent processing demands that result from the coordination and control of fingers, wrist, and arm during writing and the processing of future words or increased extension of the wrist joint as the execution of the writing progresses to the right across the page, resulting in increased stiffness in the pen-limb system. Parkinson's patients and elderly controls wrote phrases of different lengths with target patterns in various serial positions. When the number of words to be written increased, PD patients reduced their stroke size of the initial target pattern, while the elderly controls did not reduce their stroke size. There was no systematic change in stroke size of the second pattern as function of serial position. This result suggests that PD patients reduce the size of their handwriting strokes when concurrent processing load increases. © 2001 Elsevier Science
Sensorimotor Impairment in the Elderly, 1993
It has often becn suggested 0rat handwriting featurcs may allow carly diagnosis of Parkinson's discase. Instcad of searching for carly nradlcru by longitudinal studics onc may idcntify appropriate early nrarkcrs by dcrnonslrating that ilrc nrarlicrs dcpcnd littlc upon the nonnal deterioration with age whilc nrarkedly changing by thc prcscnce of thc disease. I{owever, studics of the dcvelopurcnt of handwriting skills in young adults and elderly in connection to patients rvitlr agc-rclrtcd scnsorimotor inrpairment arc sparsc. In lhe expe rinrcnt, subjects rcpeatcdly pcrfomred a sprccific handwriting pattenr undcr various conditions and instructions: writing larger, faster, or slower than nomral. or writing with reduced tactile and/or visual fecdback. The hurdrvriting pattems werc rcc<lrded in tinrc iurd space using a digitizer, autonratically scgmentcd into handwriting strokcs, and analyz.ed in temrs of venical size, pcak accelcration (i.e., force amplitudc), and duration. lvlcans arxl signal-to-noisc ratios (SNRs) wcrc cstinlatcd for cach subjcct and condition. Thc SNR rvas used to quantify in a unit-frce scale thc accuracics of sizc, forcc, and tirning contrul. It appears that in all conditions (a) tlrc accuracy of stroke sizes, (b) tlrc accuracy of pcak accelerations (i.e., force arnplitudcs) and (c) thc mean strokc duration wcrc strongly affccted by the prcscnce o[ Parliinson's discase and not b1, age. Thercforc. thcse thrcc handwriting fcaturcs nray bc considcrcd appropriatc early marlies for Parkinson's discasc.