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Translational Pediatrics Feb 2020Writing is a complex task that is vital to learning and is usually acquired in the early years of life. 'Dysgraphia' and 'specific learning disorder in written... (Review)
Review
Writing is a complex task that is vital to learning and is usually acquired in the early years of life. 'Dysgraphia' and 'specific learning disorder in written expression' are terms used to describe those individuals who, despite exposure to adequate instruction, demonstrate writing ability discordant with their cognitive level and age. Dysgraphia can present with different symptoms at different ages. Different theories have been proposed regarding the mechanisms of dysgraphia. Dysgraphia is poorly understood and is often undiagnosed. It has a high rate of co-morbidity with other learning and psychiatric disorders. The diagnosis and treatment of dysgraphia and specific learning disorders typically centers around the educational system; however, the pediatrician can play an important role in surveillance and evaluation of co-morbidity as well as provision of guidance and support.
PubMed: 32206583
DOI: 10.21037/tp.2019.11.01 -
Cerebellum (London, England) Feb 2015As early as the beginning of the nineteenth century, a variety of nonmotor cognitive and affective impairments associated with cerebellar pathology were occasionally... (Review)
Review
As early as the beginning of the nineteenth century, a variety of nonmotor cognitive and affective impairments associated with cerebellar pathology were occasionally documented. A causal link between cerebellar disease and nonmotor cognitive and affective disorders has, however, been dismissed for almost two centuries. During the past decades, the prevailing view of the cerebellum as a mere coordinator of autonomic and somatic motor function has changed fundamentally. Substantial progress has been made in elucidating the neuroanatomical connections of the cerebellum with the supratentorial association cortices that subserve nonmotor cognition and affect. Furthermore, functional neuroimaging studies and neurophysiological and neuropsychological research have shown that the cerebellum is crucially involved in modulating cognitive and affective processes. This paper presents an overview of the clinical and neuroradiological evidence supporting the view that the cerebellum plays an intrinsic part in purposeful, skilled motor actions. Despite the increasing number of studies devoted to a further refinement of the typology and anatomoclinical configurations of apraxia related to cerebellar pathology, the exact underlying pathophysiological mechanisms of cerebellar involvement remain to be elucidated. As genuine planning, organization, and execution disorders of skilled motor actions not due to motor, sensory, or general intellectual failure, the apraxias following disruption of the cerebrocerebellar network may be hypothetically considered to form part of the executive cluster of the cerebellar cognitive affective syndrome (CCAS), a highly influential concept defined by Schmahmann and Sherman (Brain 121:561-579, 1998) on the basis of four symptom clusters grouping related neurocognitive and affective deficits (executive, visuospatial, affective, and linguistic impairments). However, since only a handful of studies have explored the possible role of the cerebellum in apraxic disorders, the pathophysiological mechanisms subserving cerebellar-induced apraxia remain to be elucidated.
Topics: Agraphia; Apraxias; Cerebellum; Humans; Mastication; Radiography; Radionuclide Imaging; Speech Disorders
PubMed: 25382715
DOI: 10.1007/s12311-014-0620-1 -
Handbook of Clinical Neurology 2021Alexia refers to a reading disorder caused by some form of acquired brain pathology, most commonly a stroke or tumor, in a previously literate subject. In...
Alexia refers to a reading disorder caused by some form of acquired brain pathology, most commonly a stroke or tumor, in a previously literate subject. In neuropsychology, a distinction is made between central alexia (commonly seen in aphasia) and peripheral alexia (a perceptual or attentional deficit). The prototypical peripheral alexia is alexia without agraphia (pure alexia), where patients can write but are impaired in reading words and letters. Pure alexia is associated with damage to the left ventral occipitotemporal cortex (vOT) or its connections. Hemianopic alexia is associated with less extensive occipital damage and is caused by a visual field defect, which creates problems reading longer words and passages of text. Reading impairment can also arise due to attentional deficits, most commonly following right hemisphere or bilateral lesions. Studying patients with alexia, along with functional imaging studies of normal readers, has improved our understanding of the neurobiological processes involved in reading. A key question is whether an area in the left ventral occipitotemporal cortex is specialized for or selectively involved in word processing, or whether reading relies on tuning of more general purpose perceptual areas. Reading deficits may also be observed in dementia and traumatic brain injury, but often with less consistent deficit patterns than in patients with focal lesions.
Topics: Cerebral Cortex; Dyslexia; Humans; Stroke
PubMed: 33832678
DOI: 10.1016/B978-0-12-821377-3.00010-6 -
Frontiers in Psychology 2015Up to 17% of German school children suffer from reading and writing disabilities. Unlike developmental dyslexia, only few studies have addressed dysgraphia. Presenting a... (Review)
Review
Up to 17% of German school children suffer from reading and writing disabilities. Unlike developmental dyslexia, only few studies have addressed dysgraphia. Presenting a comprehensive overview of the current state of the art in developmental dyslexia and dysgraphia, this paper aims to determine how far existing knowledge about the causes of developmental dyslexia also apply to developmental dysgraphia. To promote understanding of developmental dysgraphia, the paper discusses relevant aspects such as predictors, causes and comorbidities, models of acquisition as well as existing deficit models. A comparison of definitions in the DSM-V and ICD-10 complemented by an overview of the most recent German guideline ought to give the reader deeper insight into this topic. The current issue of growing up bilingually and the connection between reading and writing deficits are also discussed. In conclusion, this paper presents a critical survey of theoretical and practical implications for the diagnostics and treatment of developmental dysgraphia.
PubMed: 26858664
DOI: 10.3389/fpsyg.2015.02045 -
Parkinsonism & Related Disorders May 2016This review on micrographia aims to draw the clinician's attention to non-Parkinsonian etiologies, provide clues to differential diagnosis, and summarize current... (Review)
Review
INTRODUCTION
This review on micrographia aims to draw the clinician's attention to non-Parkinsonian etiologies, provide clues to differential diagnosis, and summarize current knowledge on the phenomenology, etiology, and mechanisms underlying micrographia.
METHODS
A systematic review of the existing literature was performed.
RESULTS
Micrographia, namely small sized handwriting has long been attributed to Parkinson's disease. However, it has often been observed as part of the clinical picture of additional neurodegenerative disorders, sometimes antedating the motor signs, or following focal basal ganglia lesions without any accompanying parkinsonism, suggesting that bradykinesia and rigidity are not sine-qua-non for the development of this phenomenon. Therefore, micrographia in a patient with no signs of parkinsonism may prompt the clinician to perform imaging in order to exclude a focal basal ganglia lesion. Dopaminergic etiology in this and other cases is doubtful, since levodopa ameliorates letter stroke size only partially, and only in some patients. Parkinsonian handwriting is often characterized by lack of fluency, slowness, and less frequently by micrographia. Deviations from kinematic laws of motion that govern normal movement, including the lack of movement smoothness and inability to scale movement amplitude to the desired size, may reflect impairments in motion planning, possible loss of automaticity and reduced movement vigor.
CONCLUSIONS
The etiology, neuroanatomy, mechanisms and models of micrographia are discussed. Dysfunction of the basal ganglia circuitry induced by neurodegeneration or disruption by focal damage give rise to micrographia.
Topics: Agraphia; Basal Ganglia; Handwriting; Humans; Hypokinesia; Nerve Net; Parkinson Disease
PubMed: 26997656
DOI: 10.1016/j.parkreldis.2016.03.003 -
Frontiers of Neurology and Neuroscience 2019Studies of alexia and agraphia have played historically important roles in efforts to understand the relation between brain and behavior. In the second half of the 19th... (Review)
Review
Studies of alexia and agraphia have played historically important roles in efforts to understand the relation between brain and behavior. In the second half of the 19th century, works by Paul Broca and Carl Wernicke led to the concept of delimited cortical centers in the left cerebral hemisphere concerned with discrete aspects of spoken and written language. These specialized centers were linked by white matter pathways. Charlton Bastian, Jean-Martin Charcot, Sigmund Exner, and Jules Dejerine championed center-pathway models of reading and writing. Dejerine played a dominant role, rejecting the idea of a left frontal lobe center that mediated writing and proposing a unique, specialized role for the left angular gyrus in both reading and writing. In 1891 and 1892, he detailed the symptoms of alexia and agraphia that resulted from injury to the left angular gyrus and from the isolation of the left angular gyrus from visual input required for reading. During the early 20th century, his work and that of other so-called diagram makers was confronted and largely discredited by Pierre Marie, joined later by Henry Head and Kurt Goldstein. In the 1960s, the center-pathway model was resurrected and refined by Norman Geschwind. He drew upon foundational works of Dejerine, Hugo Liepmann, and others to describe syndromes resulting from cortical disconnections and, in doing so, helped to establish a framework for the modern discipline of behavioral neurology.
Topics: Agraphia; Dyslexia; History, 19th Century; History, 20th Century; Humans; Neurology; Research
PubMed: 31220840
DOI: 10.1159/000494951 -
Handbook of Clinical Neurology 2022This chapter gives a broad overview of the description and theorizing of a wide range of language disorders resulting from brain damage, commonly classified under the... (Review)
Review
This chapter gives a broad overview of the description and theorizing of a wide range of language disorders resulting from brain damage, commonly classified under the umbrella term "aphasia." It covers works written in Antiquity up to the 20th century. Moreover, it looks at disturbances in various language modalities such as speech, language comprehension, reading, writing, and sign language. In addition, also forms of the more recently discovered primary progressive aphasia are discussed. Finally, important developments in the history of assessment and rehabilitation of language disorders are described. To properly characterize disorders of language, these developments are discussed from the perspectives of neurology, psychology, and linguistics.
Topics: Agraphia; Aphasia; Humans; Language; Reading; Speech
PubMed: 35078608
DOI: 10.1016/B978-0-12-823384-9.00017-7 -
BMJ Case Reports Apr 2017
Topics: Agraphia; Alopecia; Brain Neoplasms; Fatal Outcome; Female; Head and Neck Neoplasms; Humans; Language Disorders; Magnetic Resonance Imaging; Melanoma; Middle Aged; Scalp; Skin Neoplasms
PubMed: 28400390
DOI: 10.1136/bcr-2017-220215