Digitized analysis of handwriting and drawing movements in healthy subjects: methods, results and perspectives

The diagnosis of movement disorders and the distinction between their possible generation by drug-treatment or illness can be done more objectively by using digitized analyses of hand movements. The aim of this study was to define this method, that is to identify its reliability and the influence of several covariables upon measurements, in healthy subjects. Simple writing and drawing tests were administered, using a digitizing tablet, transmitting signals to a computer for processing. The kinematic parameters identified in this way provided objective, reliable and valid measures for the dynamics and the degree of automation of hand movements. Analysis of the data showed that younger subjects write faster and with a higher degree of automation than older subjects. Other moderating variables, such as verbal intelligence and customary motor activity in everyday life (motoric practice) could be identified, whereas personality and gender were found to have little influence. There were no significant differences between left-handers and right-handers in hand movements. The movement parameters had a high test–retest stability. The results of this study in healthy subjects indicate that age, verbal intelligence and motor practice should be considered when evaluating the effects of drug-treatment or psychiatric illness upon hand-movement in patients.     

Hasse书写试验在精神科的临床应用

目的；探讨赫氏书写试验在临床应用的可能性。方法：对正常对照和不同的抗精神病药物治疗的虱各10例进行书写试验进行比较.分析结果：应用高效价抗精神病药物能明显影响字体大小，与剂量、疗效及副反应存在一定相关。结论：赫氏书写试验可作为临床上判断药物疗效及副反应的有用工具。     

Three-Dimensional Movement Analysis of Handwriting in Subjects With Mild Hemiparesis

Harada T, Okajima Y, Takahashi H. Three-dimensional movement analysis of handwriting in subjects with mild hemiparesis.

Objective

To investigate the effects of hemiparesis on handwriting using a 3-dimensional movement analyzer.

Design

Comparative case study.

Setting

Ambulatory care clinic.

Participants

Right-handed patients (n=25; mean age ± SD, 62.3±10y) with mild right hemiparesis secondary to subcortical stroke, and age-matched (n=10; 65.6±13y) and age-unmatched (n=15; 32.4±10y) control subjects.

Interventions

Not applicable.

Main Outcome Measures

Time required to write a Japanese character of 2 different sizes and average speed of handwriting at the pen tip. Average radii of tracks of the moving pen tip, metacarpal head of the index finger, and distal end of the forearm during writing. Correlation coefficients of the instantaneous speed-time graph of the pen tip with that of the index finger and with that of the distal forearm during writing.

Results

Time for writing with the hemiparetic right hand was longer than that with the unaffected left hand (P=.05∼.03), while it was shorter in healthy control subjects (P=.07∼.05). In contrast with the left-hand writing, the track radius of the pen tip of the right-hand writing in patients with hemiparesis with normal joint position sense was significantly larger than that of the finger or distal forearm (P=.01). The finding was the same as in the young and elderly control subjects. This right-left difference disappeared in the patients with hemiparesis with position sense impairment. The correlation coefficient of speed between the pen tip and the finger was larger in right-hand than left-hand writing in the control and sensory-normative patients with hemiparesis even though the difference was significant only in the healthy elderly subjects (P=.03). Irrespective of the right or left hand use, the correlation coefficient between the pen tip and the finger or distal forearm significantly increased as the character size increased (P=.03∼6×10⁻⁶) in all subjects and patients. However, this size-related difference was less significant in the patients with sensory impairment.

Conclusions

The characteristics of handwriting movement by the dominant hand were preserved in patients with mild dominant-hand hemiparesis when joint position sense was normative but were lost in those with position sense impairment.     

Premotor activations in response to visually presented single letters depend on the hand used to write: a study on left-handers

In a previous fMRI study on right-handers (Rhrs), we reported that part of the left ventral premotor cortex (BA6) was activated when alphabetical characters were passively observed and that the same region was also involved in handwriting [Longcamp, M., Anton, J. L., Roth, M., & Velay, J. L. (2003). Visual presentation of single letters activates a premotor area involved in writing. NeuroImage, 19, 1492-1500]. We therefore suggested that letter-viewing may induce automatic involvement of handwriting movements. In the present study, in order to confirm this hypothesis, we carried out a similar fMRI experiment on a group of left-handed subjects (Lhrs). We reasoned that if the above assumption was correct, visual perception of letters by Lhrs might automatically activate cortical motor areas coding for left-handed writing movements, i.e., areas located in the right hemisphere. The visual stimuli used here were either single letters, single pseudoletters, or a control stimulus. The subjects were asked to watch these stimuli attentively, and no response was required. The results showed that a ventral premotor cortical area (BA6) in the right hemisphere was specifically activated when Lhrs looked at letters and not at pseudoletters. This right area was symmetrically located with respect to the left one activated under the same circumstances in Rhrs. This finding supports the hypothesis that visual perception of written language evokes covert motor processes. In addition, a bilateral area, also located in the premotor cortex (BA6), but more ventrally and medially, was found to be activated in response to both letters and pseudoletters. This premotor region, which was not activated correspondingly in Rhrs, might be involved in the processing of graphic stimuli, whatever their degree of familiarity.     

The impact of tricyclic antidepressants and selective serotonin re-uptake inhibitors on handwriting movements of patients with depression

RATIONALE: Psychomotor retardation is a common symptom of patients with major depressive disorder. While a variety of clinical examinations using different techniques have been undertaken to assess the motor component of psychomotor retardation in depression, the effects of antidepressants on psychomotor functions have been examined less extensively. OBJECTIVE: The aim of the present study was to examine the effect of various pharmacological treatments on handwriting movements of patients with depression. METHODS: Kinematic data of automated handwriting movements of 18 depressed patients receiving tricyclic antidepressants (TCAs), 18 patients on selective serotonin re-uptake inhibitors (SSRIs) and 18 healthy subjects was recorded and analysed. Groups were matched according to age, sex, handedness and education level. For the assessment of fine motor movements, a digitising tablet was used. Subjects were asked to perform a simple writing task. Movement time, velocity and acceleration of the handwriting movements were measured. RESULTS: Statistical analysis of writing movements revealed motor slowing in patients receiving TCAs. In comparison with both healthy subjects and patients receiving SSRIs, the TCA group displayed an increased movement time, reduced automation of handwriting, lower maximum velocities and reduced acceleration of descending strokes. CONCLUSIONS: The results suggest either that TCAs have adverse effects on motor functioning or that they are less effective in the treatment of motor retardation than SSRIs.     

Task specific grip force control in writer’s cramp

ObjectiveWriter’s cramp is defined as a task specific focal dystonia generating hypertonic muscle co-contractions during handwriting resulting in impaired writing performance and exaggerated finger force. However, little is known about the generalisation of grip force across tasks others than writing. The aim of the study was to directly compare regulation of grip forces during handwriting with force regulation in other fine-motor tasks in patients and control subjects.MethodsHandwriting, lifting and cyclic movements of a grasped object were investigated in 21 patients and 14 controls. The applied forces were registered in all three tasks and compared between groups and tasks. In addition, task-specific measures of fine-motor skill were assessed.ResultsAs expected, patients generated exaggerated forces during handwriting compared to control subjects. However there were no statistically significant group differences during lifting and cyclic movements. The control group revealed a generalisation of grip forces across manual tasks whereas in patients there was no such correlation.ConclusionWe conclude that increased finger forces during handwriting are a task-specific phenomenon that does not necessarily generalise to other fine-motor tasks.SignificanceForce control of patients with writer’s cramp in handwriting and other fine-motor tasks is characterised by individualised control strategies.     

老年轻度认知障碍者笔迹特征及其应用价值研究

背景 书写笔迹特征分析技术已在痴呆、帕金森病等相关认知障碍检测领域得到了广泛研究，针对老年轻度认知障碍（MCI）人群的笔迹特征研究仍有待于拓展。目的 揭示老年MCI者笔迹特征与认知功能正常老年人的差异性，探讨笔迹特征在MCI筛查中的应用价值。方法 于2022年1—4月，采用便利抽样法，选取湖州市社区老年MCI者33例作为观察组，同期另选取在年龄、性别和受教育程度上与33例社区老年MCI者相匹配的社区认知功能正常老年人43例作为对照组，采用一般资料调查表、简易精神状态量表（MMSE）、蒙特利尔认知评估基础量表（MoCA-B）、日常生活能力量表（ADL）和老年抑郁量表（GDS-15）对其进行调查，并邀请受试者使用点阵数码笔完成6项书写任务（包含4项汉字书写任务、2项图形书写任务），采集受试者笔迹特征的运动学参数，通过判别分析、受试者工作特征（ROC）曲线分析笔迹特征及另设区分方案在MCI识别中的应用价值。结果 与对照组相比，在图形书写任务中，观察组受试者书写平均压力更高（Z=-2.122,P=0.034），书写思考时间（Z=-4.302,P<0.001）、落笔时间（Z=-3.663,...