Megalographia in Children with Cerebellar Lesions and in Children with Attention-Deficit/Hyperactivity Disorder

Is There a Deficit in Product and Process of Handwriting in Children with Attention Deficit Hyperactivity Disorder? A Systematic Review and Recommendations for Future Research

Handwriting abnormalities in children with attention deficit hyperactivity disorder (ADHD) have sometimes been reported both (i) at the product level (i.e., quality/legibility of the written trace and speed of writing) and (ii) at the process level (i.e., dynamic and kinematic features, such as on-paper and in-air durations, pen pressure and velocity peaks, etc.). Conversely, other works have failed to reveal any differences between ADHD and typically developing children. The question of the presence and nature of handwriting deficits in ADHD remains open and merits an in-depth examination. The aim of this systematic review was, therefore, to identify studies that have investigated the product and/or process of handwriting in children with ADHD compared to typically developing individuals. This review was conducted and reported in accordance with the PRISMA statement. A literature search was carried out using three electronic databases. The methodological quality of the studies was systematically assessed using the Critical Appraisal Skills Program (CASP) criteria. Twenty-one articles were identified. Of these, 17 described handwriting quality/legibility, 12 focused on speed and 14 analyzed the handwriting process. All the studies (100%) with satisfactory methodology procedures reported an impaired product and process in children with ADHD, while 25% evidenced a difference in the speed of production. Most importantly, the studies differed widely in their methodological approaches. Substantial gaps remain, particularly with regard to ascertaining comorbidities, ADHD subtypes and the medical status of the included children. The lack of overall homogeneity in the samples calls for higher quality studies. We conclude with recommendations for further studies.

Psychomotor intervention to improve handwriting skills in children with ADHD: A single-case experimental design with direct inter-subject and systematic replications

Dysgraphia is highly prevalent in children with attention deficit hyperactivity disorder (ADHD) and adversely affects academic and developmental trajectories. To date, no study has rigorously examined the effects of a training program on handwriting quality in this specific population. Our objective was thus to develop an innovative program - we entitled PRO-PEN - and to evaluate its effects. We planned a multiple-baseline design across participants from grade 3-5, with direct inter-subject and systematic replications. Children of Group 1 (n = 4) were diagnosed with ADHD. Systematic replication was conducted in a second group of participants (Group 2, n = 4) with a diagnosis of developmental coordination disorder in addition to ADHD. The primary assessment focused on quality of handwriting. Generalization measures evaluated diverse neuropsychological and behavioural domains. In Group 1, effect sizes regarding handwriting quality were large (Taus > .60). Improvement was also observed for children of Group 2 (Taus > .50). Importantly, the positive effects persisted three months after the end of the training. Generalization effects extended beyond handwriting sphere. Therefore, PRO-PEN can be considered a promising training program for improving handwriting quality in ADHD, with a possible impact on wide cerebral regulation loops underpinning both handwriting and other neuropsychological and behavioural domains.

Enhancing Executive Functions and Handwriting with a Concentrative Coordination Exercise in Children with ADHD: A Randomized Clinical Trial

Handwriting difficulties are common in children with Attention-Deficit/Hyperactivity Disorder (ADHD), and they have been associated with lower academic achievement and self-esteem. Our aim in this study was to determine if training coordination of the head, eyes, and arm and engaging in the necessary visual concentration associated with table tennis would improve executive functions and school-based handwriting among children with ADHD. We designed a randomized controlled trial to explore the therapeutic efficacy of this table tennis training and recruited 48 children with ADHD that we randomly assigned to one of three equal-sized training groups: (a) actual table tennis, (b) simulated table tennis (exergame), or (c) a control group receiving no additional training. The training intervention lasted 12-weeks in which the two different table tennis trainings (i.e., actual or simulated) were scheduled for three one-hour sessions per week. Outcome measures included a computerized handwriting evaluation, the Stroop test, and the Wisconsin Card Sorting Test (WCST). Participants in each table tennis training group showed significant improvements in handwriting performance, response time, and required time to achieve automation. Both intervention groups also showed significant improvements on the Stroop Color-Word test, but only the actual table tennis training group showed a significant improvement on the WCST. This study provided evidence of at least short-term improvements in executive functions and handwriting problems in children with ADHD through their participation in table tennis motor coordination activities.

How effective is fine motor training in children with ADHD? A scoping review

Background

Motor deficiencies are observed in a large number of children with ADHD. Especially fine motor impairments can lead to academic underachievement, low self-esteem and frustration in affected children. Despite these far-reaching consequences, fine motor deficiencies have remained widely undertreated in the ADHD population. The aim of this review was to systematically map the evidence on existing training programs for remediating fine motor impairments in children with ADHD and to assess their effectiveness.

Methods

The scoping review followed the PRISMA-ScR guidelines. In March 2020, PsycINFO, MEDLINE (PubMed), Web of Science, Google Scholar and The Cochrane Database of Systematic Reviews were searched for evidence. The eligibility criteria and the data charting process followed the PICO framework, complemented by study design. The investigated population included children with a formal ADHD diagnosis (either subtype) or elevated ADHD symptoms aged between 4 and 12 years, both on and off medication. All training interventions aiming at improving fine motor skills, having a fine motor component or fine motor improvements as a secondary outcome were assessed for eligibility; no comparators were specified.

Results

Twelve articles were included in the final report, comprising observational and experimental studies as well as a review. Both offline and online or virtual training interventions were reported, often accompanied by physical activity and supplemented by training sessions at home. The training programs varied in length and intensity, but generally comprised several weeks and single or multiple training sessions per week. All interventions including more than one session were effective in the treatment of fine motor deficiencies in children with ADHD and had a wide range of additional positive outcomes. The effects could be maintained at follow-up.

Conclusions

Fine motor training in children with ADHD can be very effective and multiple approaches including specific fine motor and cognitive training components, some kind of physical activity, feedback mechanisms, or multimodal treatments can be successful. Training programs need to be tailored to the specific characteristics of the ADHD population. A mHealth approach using serious games could be promising in this context due to its strong motivational components.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02916-5.

Progressive macrographia for block letter writing: A case study

"Macrographia", a relatively rare symptom generally following cerebellar diseases, consists of an abnormally large handwriting. The case reported in the present investigation shows several outstanding features. First, it is of the progressive variety, letters increase in size as one goes through the word towards the lower-right portion of space. Moreover, it is limited to one allographic variety, that is, block letters. This phenomenon is previously unreported, all allographic varieties being usually equally affected. Finally, no prominent cerebellar or basal ganglia abnormality could be demonstrated with structural MRI or PET. From a cognitive point of view, a peculiar combination of spatial attention, executive function and working memory deficits is proposed to account for the progressive misalignment and elongation of individual letters when specifically writing in block prints. From an anatomical perspective, the pattern of multifocal lesions, encompassing multiple cortical areas in both hemispheres and the corpus callosum, may support this multi-componential interpretation of the reported phenomenon.

Non-linear spelling in writing after a pure cerebellar lesion

The most common deficits in processing written language result from damage to the graphemic buffer system and refer to semantic and lexical problems or difficulties in phoneme-graphene conversion. However, a writing disorder that has not yet been studied in depth is the non-linear spelling phenomenon. Indeed, although some cases have been described, no report has exhaustively explained the cognitive mechanism and the anatomical substrates underlying this process. In the present study, we analyzed the modality of non-linear writing in a patient affected by a focal cerebellar lesion, who presented with an alteration of the normal trend to write the order of the letters. Based on this evidence, we analyzed the functional connectivity between the cerebellum and the brain network that subtends handwriting and demonstrated how the cerebellar lesion of the patient affected the connections between the cerebellum and cortical areas that support the anatomical system of writing. This is the first report of non-linear spelling in a patient with a lesion outside the fronto-parietal network, specifically with a focal cerebellar lesion. We propose that non-linear writing can be interpreted in view of the role of the cerebellum in timing and sequential processing. Thus, considering the current functional connectivity data, we hypothesize that the cerebellum might be relevant in the mechanism that allows the correct activation timing of letters within a string and placement of the letters in a specific sequential writing order.

Reduced graphomotor procedural learning in children and adolescents with ADHD

PURPOSE

The present study sought to determine if children and adolescents with ADHD demonstrate reduced procedural learning of a graphomotor program.

METHOD

Thirty-two children and adolescents between age 9 and 15 with (n = 16) and without ADHD (n = 16) participated in the study. Each group of participants practiced a novel grapheme on a digitizing tablet 30 times. Participants with ADHD were off stimulant medication or were medication naïve.

RESULTS

Control participants demonstrated significant improvement in graphomotor fluency from the beginning to the end of practice, T = 2, z = -2.534, p = .009, whereas participants with ADHD did not, T = 4, z = -1.810, p = .074.

CONCLUSIONS

Consistent with findings in adults with ADHD, results indicate that graphomotor procedural learning in children and adolescents with ADHD is attenuated. Findings have implications for future research that may inform remediation of handwriting difficulties, academic accommodations, and using digitizing technology for neuropsychological assessment.

Language and the cerebellum

During the past decades neuroanatomic, neuroimaging, and clinical studies have substantially changed the long-standing view of the role of the cerebellum as a sole coordinator of sensorimotor function. Currently, the cerebellum is considered to be crucially implicated in a variety of cognitive, affective, social, and behavioral processes as well. In this chapter we aim to summarize a number of critical insights from different research areas (neuroanatomy, functional neuroimaging, clinical practice) that provide evidence for a role of the cerebellum in motor speech and nonmotor language processing in both adults and children. Neuroanatomic studies have provided a robust basis for the development of new insights in the modulatory role of the cerebellum in neurocognition, including nonmotor language processing by means of identifying a dense network of crossed reciprocal connections between the cerebellum and the supratentorial association areas. A topologic distinction has been established between the "motor" cerebellum, projecting to the cortical motor areas, and the "cognitive/affective" cerebellum, connected with the cortical and limbic association areas. Neuroimaging studies have demonstrated cerebellar involvement in several different language tasks, even after controlling for motor aspects. In addition, several clinical studies have identified a variety of nonmotor linguistic deficits after cerebellar disease in both children and adults, implying a prominent role for the cerebellum in linguistic processes. Functional neuroimaging has confirmed the functional impact of cerebellar lesions on remote, structurally intact cortical regions via crossed cerebellocerebral diaschisis. Overall, evidence from neuroanatomic, neuroimaging, and clinical studies shows a (strongly lateralized) involvement of the cerebellum in a broad spectrum of nonmotor language functions through a dense network of crossed and reciprocal cerebellocerebral connections. It is argued that the cerebellum is involved in language in a similar manner as it is involved in motor functions: through monitoring/coordinating cortical functions via timing and sequencing mechanisms.

Dynamic balance in children with attention-deficit hyperactivity disorder and its relationship with cognitive functions and cerebellum

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is linked to the presence of motor deficiencies, including balance deficits. The cerebellum serves as an integrative structure for balance control and is also involved in cognition, including timing and anticipatory regulation. Cerebellar development may be delayed in children and adolescents with ADHD, and inconsistent reaction time is commonly seen in ADHD. We hypothesized that dynamic balance deficits would be present in children with ADHD and they would correlate with attention and cerebellar functions.

METHODS

Sixty-two children with ADHD and no other neurological conditions and 62 typically developing (TD) children were examined with five trials of the Phyaction Balance Board, an electronic balancing platform. Cerebellar clinical symptoms were evaluated using an international ataxia rating scale. Conners' Continuous Performance Test was used to evaluate patterns of reaction.

RESULTS

Children with ADHD had poorer performance on balancing tasks, compared to TD children (P<0.001). They exhibited significantly greater sway amplitudes than TD children (P<0.001) in all of the five balancing trials. The effect size of the difference between the groups increased continuously from the first to the last trial. Balance score in both groups was related to the variation in the reaction time, including reaction time standard error (r =0.25; P=0.0409, respectively, r =0.31; P=0.0131) and Variability of Standard Error (r =0.28; P=0.0252, respectively, r =0.41; P<0.001). The burden of cerebellar symptoms was strongly related to balance performance in both groups (r =0.50, P<0.001; r =0.49, P=0.001).

CONCLUSION

This study showed that ADHD may be associated with poor dynamic balance control. Furthermore, we showed that maintaining balance correlates with neuropsychological measures of consistency of reaction time. Balance deficits and impaired cognitive functioning could reflect a common cerebellar dysfunction in ADHD children.

Movement Scaling in Children With ADHD-Combined Type

OBJECTIVE

The aim of the study was to investigate motor performance in children with ADHD using a size-scaling handwriting task.

METHOD

In all, 14 male children with ADHD and 14 typically developing (TD) children (age 7-15) wrote 10-mm and 40-mm cursive letter "l."

RESULTS

Children with ADHD were unable to maintain their writing accurately at 40 mm, falling short by several millimeters; this was not evident in the TD children. Children with ADHD also had slightly faster and more fluent writing than TD children.

CONCLUSION

It was concluded that children with ADHD have difficulties scaling handwriting movement in the larger 40-mm condition that may reflect poor planning and modulation of movement, despite having faster and more fluent movements.

Handwriting in children with ADHD

OBJECTIVE

Children with ADHD-combined type (ADHD-CT) display fine and gross motor problems, often expressed as handwriting difficulties. This study aimed to kinematically characterize the handwriting of children with ADHD using a cursive letter l's task.

METHOD

In all, 28 boys (7-12 years), 14 ADHD-CT and 14 typically developing (TD), without developmental coordination disorder (DCD) or comorbid autism, wrote a series of four cursive letter l's using a graphics tablet and stylus.

RESULTS

Children with ADHD-CT had more inconsistent writing size than did TD controls. In addition, ADHD-CT symptom severity, specifically inattention, predicted poorer handwriting outcomes.

CONCLUSION

In a sample of children with ADHD-CT who do not have DCD or autism, subtle handwriting differences were evident. It was concluded that handwriting might be impaired in children with ADHD in a manner dependent on symptom severity. This may reflect reports of underlying motor impairment in ADHD.

Consensus paper: Language and the cerebellum: an ongoing enigma

In less than three decades, the concept "cerebellar neurocognition" has evolved from a mere afterthought to an entirely new and multifaceted area of neuroscientific research. A close interplay between three main strands of contemporary neuroscience induced a substantial modification of the traditional view of the cerebellum as a mere coordinator of autonomic and somatic motor functions. Indeed, the wealth of current evidence derived from detailed neuroanatomical investigations, functional neuroimaging studies with healthy subjects and patients and in-depth neuropsychological assessment of patients with cerebellar disorders shows that the cerebellum has a cardinal role to play in affective regulation, cognitive processing, and linguistic function. Although considerable progress has been made in models of cerebellar function, controversy remains regarding the exact role of the "linguistic cerebellum" in a broad variety of nonmotor language processes. This consensus paper brings together a range of different viewpoints and opinions regarding the contribution of the cerebellum to language function. Recent developments and insights in the nonmotor modulatory role of the cerebellum in language and some related disorders will be discussed. The role of the cerebellum in speech and language perception, in motor speech planning including apraxia of speech, in verbal working memory, in phonological and semantic verbal fluency, in syntax processing, in the dynamics of language production, in reading and in writing will be addressed. In addition, the functional topography of the linguistic cerebellum and the contribution of the deep nuclei to linguistic function will be briefly discussed. As such, a framework for debate and discussion will be offered in this consensus paper.

Brainstem arteriovenous malformation presenting with dyspraxic handwriting in a young girl

We report the case of a 11-year-old girl who developed an isolated hand-writing disorder with dysgraphia at the beginning of the school year in the sixth grade. A brain magnetic resonance angiography showed a round arteriovenous malformation sited in the left side of the midbrain extending to the ipsilateral medio-basal thalamus. Child neurologists should never neglect a thorough neurological evaluation in case of isolated worsening of handwriting, to rule out possible underlying organic causes.

Neural correlates of paediatric dysgraphia

Writing is an important skill that is related both to school performance and to psychosocial outcomes such as the child's self-esteem. Deficits in handwriting performance are frequently encountered in children with developmental coordination disorder. This review focuses on what is known about the neural correlates of atypical handwriting in children. Knowledge of the neural correlates is derived from studies using clinical case designs (e.g. lesion studies), studies using neuroimaging, and assessment of minor neurological dysfunction. The two functional imaging studies suggest a contribution of cortical areas and the cerebellum. The largest study indicated that cortical areas in all regions of the brain are involved (frontal, temporal, parietal, and occipital). The two lesion studies confirmed cerebellar involvement. The findings of the study on minor neurological dysfunction in children with writing problems correspond to the imaging results. The limited data on the neural substrate of paediatric dysgraphia suggest that at least a subset of the children with dysgraphia have dysfunctions in extensive supraspinal networks. In others, dysfunction may be restricted to either the cerebellum or specific cortical sites.

Understanding macrographia in children with autism spectrum disorders

It has been consistently reported that children with autism spectrum disorders (ASD) show considerable handwriting difficulties, specifically relating to accurate and consistent letter formation, and maintaining appropriate letter size. The aim of this study was to investigate the underlying factors that contribute to these difficulties, specifically relating to motor control. We examined the integrity of fundamental handwriting movements and contributions of neuromotor noise in 26 children with ASD aged 8-13 years (IQ>75), and 17 typically developing controls. Children wrote a series of four cursive letter l's using a graphics tablet and stylus. Children with ASD had significantly larger stroke height and width, more variable movement trajectory, and higher movement velocities. The absolute level of neuromotor noise in the velocity profiles, as measured by power spectral density analysis, was significantly higher in children with ASD; relatively higher neuromotor noise was found in bands >3 Hz. Our findings suggest that significant instability of fundamental handwriting movements, in combination with atypical biomechanical strategies, contribute to larger and less consistent handwriting in children with ASD.

Handwriting performance and underlying factors in children with Attention Deficit Hyperactivity Disorder

Preliminary evidence suggests that handwriting difficulties are common to children with Attention Deficit Hyperactivity Disorder (ADHD). However, the nature of the task-specific impairments is needed to be clarified. The aim of this study was to describe handwriting capacity in ADHD children without DCD and identify underlying factors of performance by use of outcome-oriented assessments and a digitizing tablet. Twenty-one children with ADHD (8.59±1.25 years) and 21 match controls (8.5±1.08 years) were recruited. Children with ADHD scored lower than controls on Tseng Handwriting Problem Checklist and writing composite of Basic Reading and Writing Test, indicating the ADHD group wrote less legibly. The ADHD group spent more on-paper time to copy 50 Chinese characters and exhibited more writing time during the writing process. The ADHD group scored significantly lower on tasks demanding upper limb and eye-hand coordination and visual-motor integration compared with controls. Furthermore, motor skill and visual-motor integration were positively correlated with the legibility. Motor skill was negatively correlated with writing time, in-air time, and in-air trajectory.

Changes in kinetics and kinematics of handwriting during a prolonged writing task in children with and without dysgraphia

Handwriting difficulties or dysgraphia have a profound impact on children's psychosocial development, and yet, 10-30% of school-aged children are reported to experience difficulties mastering this skill. Several studies have examined the nature and biomechanical underpinnings of handwriting difficulties in children with and without dysgraphia. While the majority of these studies have considered short handwriting activities involving a sentence or a paragraph, handwriting quality and speed are reported to vary with the length of the writing task. Further, it is suggested that the biomechanics of handwriting also evolve over extended writing periods, and that these changes may be distinct between children with and without dysgraphia. The nature and specificity of these biomechanical alterations remain unknown. To address this knowledge gap, we examined changes in writing speed, grip forces on the pen barrel, and normal forces on the writing surface, over the course of a 10-min writing task, in a large cohort of 4th grade children with and without dysgraphia. Horizontal stroke speed, grip force and normal force increased over time while vertical stroke speed decreased in all children. These biomechanical changes may be attributable to physical and psychological fatigue and the corresponding compensatory processes invoked by the motor system.