Cognitive neuropsychological analysis of isolated agraphia: Review and report of a new case

• Finding: isolated agraphia is not a unitary syndrome.
• Phonological mediation for writing is not mandatory.
• Left parietal lobe plays a significant role in spelling/writing.
• Argues for the need for cross-script study of dysgraphias.

The present study offers a brief review of the literature about isolated agraphia (IA) and discusses a new case in the context of contemporary neuropsychological models of reading and spelling. The studies of IA, within the cognitive neuropsychological framework, have dealt with issues related to the universality of cognitive models, the autonomy of orthographic lexicon/phonological mediation of writing/spelling, the multiplicity of patterns of symptoms associated with IA, and the neural bases of IA. CBH, a 59-year-old female, freelance journalist with a history of stroke-induced bilateral parietal lobe lesion displayed symptoms of IA. CBH's performance on experimental tasks related to reading and writing suggests that IA may not be restricted to one or the other syndrome of dysgraphia, access to the orthographic lexicon does not require phonological mediation, hence, it is autonomous, and the left parietal lobe plays a crucial role in spelling.