Dysgraphic features in motor neuron disease: a review

Abstract

Background. Motor neuron disease (MND) patients can show oral language deficits mimicking those of frontotemporal degenerations (FTD). Although dysgraphic features have been also reported within the MND-FTD continuum, their characteristics and clinical relevance are still largely unexplored. Aims.To profile writing disorders in MND patients can help further define their cognitive semiology and thus conveys relevant clinical entailments. Therefore, this study aimed at reviewing evidence of writing impairment in MND patients. This review was implemented and reported by consulting Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Qualitative/quantitative measures of writing abilities in MND patients was the primary outcome. Both group studies and case reports/series were taken into consideration.Twenty-four contributions were included out of an initial N=83. Potential biases in generalizing results were qualitatively controlled for by extracting background, disease-related, neuropsychological and neuroanatomofunctional secondary outcomes. Main Contribution.Fifteen studies assessed writing abilities in Japaneses patients, whereas the remaining eight in western patients. Central dysgraphic features were reported in both neuropsychologically-impaired and -unimpaired MND patients. Phonetic/phonological NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.paragraphias and morpho-syntactic errors were frequently reported. Although FTD was frequently co-occurent, neither cognitive nor language impairment fully accounted for writing impairment in some patients. By contrast, evidence of peripheral dysgraphia was scarce.Patients displaying writing deficits often presented with bulbar signs and perisylvian cortices involvement (including Exner's area and the left angular gyrus). Writing deficits proved to be associated with abnormalities in executive functioning and its neural substrates. Writing-todictation tasks as well as writing samples assessment proved to be useful to detect writing errors.Conclusions. Dysgraphic features in MND patients might be due to dysfunctions of the graphemic buffer -and possibly the phonological route. The lexico-semantic route appeared to be less involved. However, a mixed peripheral/central involvement cannot be ruled out. In this population, executive/attentive deficits are likely to contribute to writing errors as well. Writing deficits might thus be specific of MND patients' cognitive/language impairment profile. The evaluation of writing abilities via writing-to-dictation/narrative writing tasks may be useful when assessing cognition/language in both neuropsychological-impaired and -unimpaired MND patients -especially when severe dysarthria/anarthria is present and prevents clinicians from assessing oral language.

Prevalence and determinants of language impairment in non‐demented amyotrophic lateral sclerosis patients

“…Relatedly, it has to be mentioned that the present prevalence estimate is measure‐dependent, thus coming with the potential biases intrinsic to the ECAS‐Language. In this regard, it has been highlighted that, compared to other ECAS subscales, the ECAS‐Language might suffer from a slightly poorer sensitivity [ 27 ], with such an issue having been attributed to it not optimally covering the full spectrum of LI typical of non‐demented ALS patients [ 2 , 3 , 4 , 27 ]. Consistently, the present work highlights that the Naming and, to an even greater extent, Spelling tasks of the ECAS‐Language are the major drivers of the performance on this subscale, at variance with the Comprehension task [ 25 ].…”

“…Language impairment (LI) within the spectrum of primary progressive aphasia (PPA) is typical of non‐demented amyotrophic lateral sclerosis (ALS) patients' cognitive profile [ 1 ], including phonological, lexical‐semantic and morpho‐syntactic deficits, alterations in connected speech and pragmatics [ 2 , 3 ], as well as dysgraphic features [ 4 ].…”

“…However, despite much being known on the semiology of LI in non‐demented ALS patients [ 2 , 3 , 4 ], its epidemiology in this population is still largely obscure. Indeed, the currently accepted prevalence estimate of LI in non‐demented ALS patients (i.e., ≈35%–40%) [ 1 , 7 ] relies on the 2013 pioneering study by Taylor et al [ 8 ], which, however, (i) addressed a relatively small sample size ( N = 50) and (ii) did not include ALS‐specific language measures.…”

Primary progressive aphasia and motor neuron disease: A review

“…Studies describing anarthric patients whose language was assessable only through writing were included only if an explicit mention to aphasia was made ( Aiello et al, 2021 ).…”

Understanding dysgraphia

“…Adults generally develop dysgraphia due to cerebral dysfunction from trauma, infections, and disease that damage the brain's parietal lobe 4. People with neurologic disorders such as cerebrovascular injury, Huntington disease, multiple sclerosis, Alzheimer disease, vascular dementia, and Parkinson disease may exhibit dysgraphia at different times during the disease processes 6. The National Institute of Neurological Disorders and Stroke reports that dysgraphia is frequently observed in cerebrovascular events and frontotemporal dementia 7,8.…”