A Quantitative Measure of Handwriting Dysfluency for Assessing Tardive Dyskinesia

Abstract

Tardive dyskinesia (TD) is movement disorder commonly associated with chronic exposure to antidopaminergic medications which may be in some cases disfiguring and socially disabling. The consensus from a growing body of research on the incidence and prevalence of TD in the modern era of antipsychotics indicates that this disorder has not disappeared continues to challenge the effective management of psychotic symptoms in patients with schizophrenia. A fundamental component in an effective strategy for managing TD is its reliable and accurate assessment. In the present study, we examined the clinical utility of a brief handwriting dysfluency measure for quantifying TD. Digitized samples of handwritten circles and loops were obtained from 62 psychosis patients with or without TD and from 50 healthy subjects. Two measures of dysfluent pen movements were extracted from each vertical pen stroke, including normalized jerk and the number of acceleration peaks. TD patients exhibited significantly higher dysfluency scores than non-TD patients and controls. Severity of handwriting movement dysfluency was correlated with AIMS severity ratings for some tasks. The procedure yielded high degrees of test-retest reliability. These results suggest that measures of handwriting movement dysfluency may be particularly useful for objectively evaluating the efficacy of pharmacotherapeutic strategies for treating TD.

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

“…This priority shift may also explain the increase of the normalized jerk accompanying the benefits on writing size, which may be a direct consequence of a system overload expressed as a loss of movement fluency. Worsening of writing fluency when movements are executed more slowly or with a larger amplitude is in agreement with previous studies in healthy young adults and other patient groups [ 43 , 44 ]. Interestingly, in support of this hypothesis, we found that a worse cognitive profile and more advanced disease, represented by more sequential upper limb difficulties, resulted in a greater trade-off for movement duration and normalized jerk.…”

Exploring the Relationship of Transdiagnostic Mood and Psychosis Symptom Domains with Motor Dysfunction

“…MovAlyzeR software (Neuroscript, LLC, Tempe, AZ, USA) was used to sample pen movements and for data processing and analysis. Data processing steps and additional analysis details are described in Caligiuri et al [63] and Kent et al [12]. Briefly, average normalized jerk (ANJ) was calculated [64] as an index of movement smoothness [65].…”

“…Jerk, the third time derivative, is calculated and normalized for vertical stroke size and duration (resulting in a unit-free value) [64] and averaged across strokes and trials. ANJ, which reflects changes in acceleration during movement, has been used previously to quantify dysfluent movement, or dyskinesia (indicated by higher ANJ values) [12,63,64,66,67]. Because our previous work demonstrated no main effect or interactions involving the size condition [12], we averaged ANJ across size conditions for the current secondary analysis.…”

Mudança na Destreza Manual do Aluno com Paralisia Cerebral Frente ao Mobiliário Escolar Adequado

“…The digitizing table used was Wacom, Intuos3, model PTZ-930, with a total height of 25.5 centimeters (cm) and a total length of 34 cm, with a writing area of 16.1 cm in height and 21 cm in length, referring to sheet A4, normal ( Figure 1). This type of digitizing table has been considered an instrument with objective parameters for the evaluation of the movements of the fingers and the readability of the writing (Yu, Van Gemmert, & Chang, 2017;Caligiuri, Teulings, Dean, & Lohr, 2015;Piovezanni, Rocha, & Braccialli, 2014;Van Roon et al, 2005). It was set according to the manufacturer standards so that the computer could record pen pressure data, even if the child had difficulty in pressing force on the pen.…”