Agraphia and micrographia: Clinical manifestations of motor programming and performance disorders

Margolin, David I.; Wing, Alan M.

doi:10.1016/0001-6918(83)90039-2

Cited by 94 publications

(47 citation statements)

References 14 publications

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“…In a previous study, impairment of handwriting in patients with Parkinson's disease had been characterized by a decrease in the velocity of stroke formation (16). This parameter was correlated with a reduction in letter height and the speed of handwriting in patients with long-standing disease.…”

Section: Discussionmentioning

confidence: 85%

“…This parameter was correlated with a reduction in letter height and the speed of handwriting in patients with long-standing disease. The process underlying this finding was thought to be a diminution in the effective force creating the letter strokes (16). Another study revealed that patients with Parkinson's disease showed an impaired control of the force amplitudes of their handwriting movements (14).…”

Section: Discussionmentioning

confidence: 99%

“…A disturbance of open loop handwriting movements may therefore be a sensitive marker for early parkinsonism (16,25,26). The clinical usefulness of this procedure is currently being tested by a prospective study of consecutively ad-…”

Section: Discussionmentioning

confidence: 99%

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Computational analysis of open loop handwriting movements in Parkinson's disease: A rapid method to detect dopamimetic effects

et al. 1996

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We used a computational analysis of open loop handwriting movements and a clinical rating scale for monitoring the effect of apomorphine in 16 patients with early untreated parkinsonism [subsequently L-DOPA responsive, probable Parkinson's disease (PD)], six patients with long-standing PD with L-DOPA associated motor fluctuations, and seven patients with known L-DOPA unresponsive parkinsonism. Subjects were instructed to write fluently concentric circles of approximately 12 mm in diameter. Movements were recorded for two periods of 3 s each, using a digitizing tablet. Mean peak velocity (Vmax) and mean peak acceleration (Amax) were determined. In addition, two sensitive indices describing the degree of automation of handwriting were derived: (a) NCV, calculated as the mean Number of Changes in direction of Velocity per half circle, and (b) NCA, the mean Number of Changes in the direction of Acceleration. Clinical rating was performed according to the Unified Parkinson's Disease Rating Scale part III (UPDRS III). After apomorphine injection, the patients with early untreated probable PD showed significant improvement of Vmax, Amax, NCV, NCA, and UPDRS III scores. Likewise, the patients with long-standing PD improved significantly in all kinematic parameters and UPDRS III scores. Patients with L-DOPA unresponsive parkinsonism failed to change significantly in any of the parameters tested. These observations suggest that the computer-assisted analysis of automated handwriting movements can be used as an objective quick method for quantifying dopamimetic effects on the kinematics of handwriting movements in parkinsonian patients.

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Section: Discussionmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 99%

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Computational analysis of open loop handwriting movements in Parkinson's disease: A rapid method to detect dopamimetic effects

et al. 1996

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“…Other types of limb praxis are assumed to be normal in these patients. Several case reports of this type of dysgraphia have been published (Baxter & Warrington, 1986;Margolin & Wing, 1983;Levine et al, 1988). A number of patients fail to write even the single components of the graphomotor patterns, producing a written output so spatially distorted to become nothing more than an illegible scrawl.…”

Section: Graphomotor Similarity Analysismentioning

confidence: 99%

Selective Uppercase Dysgraphia with Loss of Visual Imagery of Letter Forms: A Window on the Organization of Graphomotor Patterns

et al. 2000

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“…A wide variety of techniques including analyses of writing errors, anecdotal records of neurological patients. and reaction times have supported that a plan, that is the representation of the serial order, in handwriting is hierarchical in nature (see Ellise, 1979;Margolin & Wing, 1983;Teulings, Thomassen, & van Galen, 1983). In writing a word, thus, which word is to be written determines the order of letters, and which letter is to be written determines the order of strokes.…”

mentioning

confidence: 99%

Effects of delayed visual feedback on handwriting

Tamada

1995

Jpn. Psychol. Res

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We investigated effects of delayed visual feedback on handwriting some familiar English words, using various delays -0, 33. 67, 100, 133, 167, 267, and 500 ms. With increasing the delay, the writing error rate increased. Among the writing errors, there was a tendency for some additional strokes to be inserted, especially for sonic original strokes to be duplicated. This type of error named "addition error" was observed frequently where a set of strokes should be repeated (e.g. the word "feeling" was often misspelled as "feeeling"). These results indicate that visual monitoring is indispensable in producing repetition of a set of strokes.Key words: delayed visual feedback, handwriting, addition errors, visual monitoring.A word can he decomposed into subunits, letters and strokes, so handwriting a word needs sequencing these subunits. Lashley (1951) emphasized the importance of the serial order problem, and proposed that the sequence of skilled motor activity is guided not by any type of associative chain but by a plan. Most of recent studies on human motor activity has accepted the idea of the motor plan. A wide variety of techniques including analyses of writing errors, anecdotal records of neurological patients. and reaction times have supported that a plan, that is the representation of the serial order, in handwriting is hierarchical in nature (see Ellise, 1979;Margolin & Wing, 1983;Teulings, Thomassen, & van Galen, 1983). In writing a word, thus, which word is to be written determines the order of letters, and which letter is to be written determines the order of strokes.Although many researchers agree that the motor plan is organized hierarchically, it is still unclear how a given motor system reads out and executes the plan. To investigate these processes, it may be instructive how we adjust our movements based on sensory information.We must detect and correct errors on the basis of sensory information during movements because the environments around us are always changing. Thus, in order to fully understand the way that a certain motor system behaves, as stressed by Cruse, Dean, Heuer, and Schmidt (1990), it must be accounted for how the system can incorporate sensory information with the motor control processes which obey the plan. Research on human motor behavior during last few decades has shown that the system behaves neither exclusively in a closed-loop fashion nor an open-loop fashion, but in a hybrid (mixed) fashion (Schmidt, 1988). It follows that the focus of motor behavior research is to find how sensory information could be integrated with the motor processes at different levels of hierarchy of the motor plan. The main concern of the present study is how visual information can be incorporated into the plan in the course of its execution in handwriting.One method for investigating the above question of visuo-motor integration is to introduce delayed visual feedback. The motor system usually goes on modifying the action to lead a successful performance when it detects some errors, extrinsic or in...

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Agraphia and micrographia: Clinical manifestations of motor programming and performance disorders

Cited by 94 publications

References 14 publications

Computational analysis of open loop handwriting movements in Parkinson's disease: A rapid method to detect dopamimetic effects

Computational analysis of open loop handwriting movements in Parkinson's disease: A rapid method to detect dopamimetic effects

Selective Uppercase Dysgraphia with Loss of Visual Imagery of Letter Forms: A Window on the Organization of Graphomotor Patterns

Effects of delayed visual feedback on handwriting

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