Apraxic agraphia: An insight into the writing disturbances of posterior aphasias

Department of Speech and Hearing, Kasturba Hospital, Manipal University, India.
Annals of Indian Academy of Neurology (Impact Factor: 0.6). 04/2009; 12(2):120-3. DOI: 10.4103/0972-2327.53082
Source: PubMed


Reading and writing disturbances are common accompaniments of aphasia following brain damage. However, impaired writing in the absence of apparent primary linguistic disturbances is infrequently reported in the literature.
A 67-year-old right-handed subject underwent neurological, neuroradiological, and linguistic investigations following development of a minimal right upper limb weakness.
The patient had polycythemia and the neurological investigation revealed right upper limb paresis. The neuroradiological investigation revealed hypodense areas involving the gray-white matter of the left postero-parietal and frontal lobe, left caudate and lentiform nuclei, and the anterior limb of the internal capsule, suggesting an infarct. The linguistic investigation revealed a mild anomic aphasia with apraxic agraphia. This mild anomic aphasia resulted primarily from the relatively poor scores on the verbal fluency tests.
The marked writing impairment, even with the left hand, points to disturbances in written output - apraxic agraphia - in the presence of near-normal spoken output. This finding should raise suspicion about hidden apraxic agraphia in subjects with posterior aphasias.

Download full-text


Available from: Gopee Krishnan, Feb 05, 2015
  • Source
    • "In the literature pure agraphia and aphasic agraphia are used as synonyms (e.g. Aiba, Souma, Aiba, Kulita, & Kishida, 1991; Assal, Chapuis, & Zander, 1970; Ikegami, Kojima, Maeda, Hojo, & Fujishima, 2006; Krishnan, Rao, & Rajashekar, 2009; Laine & Martilla, 1981; Ogura, FujiI, Suzuki, & Mori, 2013; Rosati & De Bastiani, 1979; Toyokura, Kobayashi, & Aono, 2010; Yaguchi, Bando, Kubo, Ohi, & Suzuki, 1998; Yokota, Ishiai, Furukawa, & Tsukagoshi, 1990). AA is a peripheral dysgraphia that results from distortion of the mental representation, planning, and execution of graphomotor letter formation. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: Apraxic agraphia (AA) is a peripheral writing disorder generally considered to result from a causative lesion in the parietal and/or prefrontal lobe of the language dominant hemisphere (De Smet, Engelborghs, Paquier, De Deyn, & Mariën, 2011). De Smet et al. (2011), however, confirmed that AA might be associated with lesions outside the typical language areas such as the cerebellum or the thalamus. We report a 32-year-old ambidextrous patient with a left frontal lobectomy who following bilateral thalamic damage developed AA. Method: Detailed neurolinguistic and neurocognitive test results were obtained after resection of an extensive left frontal lobe tumour by means of a set of standardised tests. Repeated investigations were performed after a bithalamic stroke. Functional imaging was performed by means of quantified SPECT. Results: Normal neurolinguistic test results were obtained after tumour resection. Neurocognitive test results, however, showed a dysexecutive syndrome and frontal behavioural deficits, including response inhibition. AA occurred after a bithalamic stroke while non-handwriting written language skills, such as typing, were normal. Quantified SPECT showed a significant bifrontal hypoperfusion. Conclusion: Neurolinguistic follow-up findings and SPECT evidence in this unique patient with bithalamic damage for the first time indicate that AA in the alphabetic script may result from diaschisis affecting the frontal writing centre. The findings suggest that the thalamus is critically implicated in the neural network subserving graphomotor processing. Copyright © 2015 Elsevier Inc. All rights reserved.
    Full-text · Article · Feb 2015 · Brain and Cognition
  • [Show abstract] [Hide abstract]
    ABSTRACT: Apraxic agraphia (AA) is a so-called peripheral writing disorder following disruption of the skilled movement plans of writing while the central processes that subserve spelling are intact. It has been observed in a variety of etiologically heterogeneous neurological disorders typically associated with lesions located in the language dominant parietal and frontal region. The condition is characterized by a hesitant, incomplete, imprecise or even illegible graphomotor output. Letter formation cannot be attributed to sensorimotor, extrapyramidal or cerebellar dysfunction affecting the writing limb. Detailed clinical, neurocognitive, neurolinguistic and (functional) neuroimaging characteristics of three unique cases are reported that developed AA following a thalamic stroke. In marked contrast to impaired handwriting, non-handwriting skills, such as oral spelling, were hardly impaired. Quantified Tc-99m ECD SPECT consistently showed a decreased perfusion in the anatomoclinically suspected prefrontal regions. The findings suggest crucial involvement of the anterior (and medial) portion of the left thalamus within the neural network subserving the graphomotor system. Functional neuroimaging findings seem to indicate that AA after focal thalamic damage represents a diaschisis phenomenon.
    No preview · Article · Oct 2015 · Brain and Language