[Pure agraphia with topographical disorientation caused by right hemisphere lesion]

Dementia with Lewy Bodies with Pure Agraphia for Kanji (Japanese Morphograms)

A 70-year-old dextral woman was admitted to a hospital with agraphia for kanji (Japanese morphograms). She had a history of severe constipation, nightmares, and visual hallucinations. Neurological examinations revealed no obvious Parkinson's disease symptoms. She showed poor skills in writing the kanji for looking at picture objects, [e.g., writing the Japanese word "inu" (which means dog) when she saw a drawing of a dog] or dictated words. A reduced striatal uptake of [¹²³I]-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FP-CIT) on single-photon-emission computed tomography and reduced meta-iodobenzylguanidine (MIBG) cardiac uptake on myocardial scintigraphy were detected. The accumulation of amyloid beta in the bilateral cerebral cortices was observed on amyloid-positron emission tomography. We herein report a case of Lewy body dementia with pure agraphia for kanji with underlying Alzheimer's disease pathology.

Delineating the cognitive-neural substrates of writing: a large scale behavioral and voxel based morphometry study

The current study investigated the cognitive and neural substrates that underpin writing ability. We explored similarities and differences in writing numbers and words and compared these to language and manual actions in a large group of sub-acute, stroke patients (n = 740). The behavioral data showed association and dissociation in the ability to write words and numbers. Comorbidities of writing deficits with both language and motor impairments were prevalent, with less than a handful showing deficits restricted to the writing tasks. A second analysis with a subset of patients (n = 267) explored the neural networks that mediate writing abilities. Lesion to right temporal contributed to writing words, while lesions to left postcentral contributed to writing numbers. Overlapping neural mechanisms included the bilateral prefrontal cortex, right inferior parietal, left middle occipital and the right cerebellum. With the former regions associated with error pattern typical to writing based on prior knowledge (the lexical route), while lesion to left MOG was associated with errors to the phonological (non-lexical) route. Using principle components extracted from the behavioral data, we showed that right prefrontal and right parietal contributed to the ability to use pen, while lesion to bilateral prefrontal, inferior temporal and cerebellum supported unique use of pen for writing. The behavioral and imaging data suggested that writing numbers and words primarily relied on overlapping cognitive and neural functions. Incidents of pure writing deficits, in the absence of motor or language deficits were rare. Nevertheless, the PCA and neural data suggested that writing abilities were associated with some unique neuro-cognitive functions, specifically dedicated to the use of pen and the ability to transform meaning to motor command.