Frontal allographic agraphia in a patient with behavioral variant frontotemporal dementia

ABSTRACT

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.

KEYWORDS:

• Aphasia
• allographic agraphia
• frontotemporal dementia
• katakana
• unidirectional allographic conversion

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No potential conflict of interest was reported by the author(s).

Data availability statement

The original contributions presented in the study are included in the article; further inquiries can be directed to the corresponding author.

Additional information

Funding

The authors did not receive support from any organization for the submitted work.