Progressive peripheral agraphia

Frontal allographic agraphia in a patient with behavioral variant frontotemporal dementia

We report a patient with behavioral variant frontotemporal dementia who developed agraphia, irritability, perseverative and stereotyped behavior, and dietary changes. MRI revealed bilateral frontal convexity atrophy. Neuropsychological examination showed fluent aphasia with perseverative allographic agraphia, mild semantic impairment, and dysexecutive syndrome. Allographic agraphia featured unidirectional conversion from hiragana (cursive form of Japanese phonograms) and kanji (Japanese morphograms) to katakana (square form of Japanese phonograms), as opposed to mutual (bidirectional) conversion between hiragana and katakana in parieto-occipital gyri lesions. Furthermore, all letters of the word were converted and this whole-word conversion may be characteristic of perseverative behavior in frontotemporal dementia.

The specificity of notation codes in apraxic agraphia: dissociation between Arabic and alphabetical scripts in a patient with severe ideomotor and visuoconstructional apraxia

This article describes the case of a patient with corticobasal syndrome, who showed severe ideomotor and visuoconstructional apraxia along with handwriting difficulties more marked for letters and words than for digits and numbers. For alphabetical script, these difficulties were less marked when graphic motor patterns were activated with a model, whilst for digits IV's graphic productions were better in dictation. Moreover, IV's graphic production was negatively influenced by graphomotor complexity for letters but not for numbers. IV is the first reported case of a patient with severe limb apraxia, who also showed peripheral agraphia, with dissociation in alphabetical and numerical notation codes resulting from a specific deficit in the activation of graphomotor programs.

Progressive agraphia can be a harbinger of degenerative dementia

By investigating three patients with progressive agraphia, we explored the possibility that this entity is an early sign of degenerative dementia. Initially, these patients complained primarily of difficulties writing Kanji (Japanese morphograms) while other language and cognitive impairments were relatively milder. Impairments in writing Kana (Japanese syllabograms), verbal language, executive function, visuo- and visuospatial cognition and memory were identified by neuropsychological testing. The agraphia was compatible with a peripheral type, based on deficits at the interface between the central letter selection and the graphemic motor execution (Patient 1) or at the stage of central letter selection as well (Patients 2 and 3). Agraphia was generally more prominent, although not exclusive, for Kanji probably because of later acquisition and larger total number of Kanji letters leading to lower frequency of use and familiarity per letter. Concurrent or subsequent emergence of non-fluent aphasia, ideomotor apraxia, executive dysfunction and asymmetric akinetic-rigid syndrome in two patients suggested degenerative processes involving the parietal-occipital-temporal regions, basal ganglia and striato-frontal projections. We propose that progressive agraphia may be one of the early symptoms of degenerative dementia such as corticobasal degeneration.

Allographic agraphia: a case study

We report the case of patient MN, diagnosed with frontotemporal dementia, who exhibited a severe impairment in writing letters and words in upper-case print in the face of accurate production of the same stimuli in lower-case cursive. In contrast to her written production difficulties, MN was unimpaired in recognizing visually presented letters and words in upper-case print. We find a modest benefit of visual form cueing in the written production of upper-case letters, despite an inability to describe or report visual features of letters in any case or font. This case increases our understanding of the allographic level of letter-shape representation in written language production. It provides strong support for previous reports indicating the neural independence of different types of case and font-specific letter-shape information; it provides evidence that letter-shape production does not require explicit access to information about the visual attributes of letter shapes and, finally, it reveals the possibility of interaction between processes involved in letter-shape production and perception.

Isolated Inability to Write Cursively After Transient Ischemic Attack (TIA)

OBJECTIVE

To examine the different aspects of language and its representation in the brain.

BACKGROUND

Apractic agraphia, a form of mechanical agraphia, is produced by lesions in the left superior parietal lobe. However, little is known about the dissociation between allographic level representations for cursive writing and printing.

METHOD

A 78-year-old right-handed patient with a history of transient ischemic attack was evaluated by interview, neurologic and neuropsychiatric examination, neuropsychologic testing, speech and language evaluation, and functional neuroimaging (single photon emission computed tomography).

RESULTS

The patient exhibited a disorder strictly limited to cursive writing resulting from ischemic damage to parietal and occipital lobes bilateral.

CONCLUSIONS

These findings support the assertion that printing and cursive writing are represented differentially and an isolated deficit in any of them can be the only presentation of disorder of language organization, secondary to brain damage in left superior parietal area.

Writing through the phonological buffer: a case of progressive writing disorder

A progressively dysgraphic patient is described, whose deficit involved, at different stages, the post-allographic, the allographic and the orthographic representation of words. The patient's roughly comparable difficulties in oral and written spelling and in dictation by composition, as the disease progressed, showed that the damage was no longer limited to output mechanisms but also involved more central processes. The nature of the errors (phonologically based), their identical distributions for words and non-words, the inability to write under articulatory suppression, the normal repetition and the impairment in reading and lexical decision suggest that the patient cannot rely on the orthographic representation of words and instead makes use of a phonological representation by spelling through the phonological buffer.

Progressive Agraphia, Acalculia, and Anomia: A Single Case Report

A case of a 50-year-old, right-handed female, mono-lingual native Spanish-speaker with a university-level education and cognitive changes is reported. Over approximately 2 years, she presented with a progressive deterioration of writing abilities associated with acalculia and anomia. An MRI disclosed a left parietal temporal atrophy. Two years later, further significant cognitive decline consistent with a dementia of the Alzheimer's type was observed. Amnesia, executive dysfunction, and ideomotor apraxia were found. Writing was severely impaired, and some difficulties in reading were observed. Copying abilities, however, were relatively well preserved, and the patient could drive and go to different city locations without significant spatial orientation difficulties. A second MRI approximately 2 years later showed that brain atrophy had progressed significantly. Spontaneous writing and writing to dictation were impossible. The ability to read words was preserved, but the ability to read pseudowords was lost. Changes in calligraphy were noted. This case clearly illustrates the progression of focal cognitive defects over time and the spread of abnormalities to other domains.

When writing 0 (zero) is easier than writing O (o): a neuropsychological case study of agraphia

Though a few case studies reported a dissociation between intact writing of Arabic and impaired writing of alphabetical script, a detailed experimental analysis of such a dissociation is still lacking. We report a follow-up study of a patient with a parieto-occipital lesion who is affected by severe peripheral agraphia for letters, but not for Arabic digits. While letters in writing to dictation are frequently illegible, distorted, or consist in meaningless strokes, Arabic digits are well-formed and fluently produced. In a series of tasks, including copying of letters with tachistoscopic presentation and handwriting on a digitizing tablet, several processing levels are assessed in order to localize JS' functional writing impairment and to determine different processing routes for letters and for numbers. Overall, the results of the experimental investigation suggest a notation specific deficit in the activation of graphomotor patterns for letters, but not for digits. The study thus adds evidence to the so far reported dissociations between Arabic and alphabetical scripts.