Abstract
Descriptions on writing errors in patients with amyotrophic lateral sclerosis (ALS) were reviewed. A Japanese patient with ALS who showed writing errors with paragraphia was reported as early as 1893. This is now considered to be the first report on not only ALS with dementia (ALS-D) but also aphasia in Japan. Most of other literatures describing writing errors were reported in late 1990s, after the concept of frontotemporal lobe dementia (FTD) became recognized in association with ALS. In the literatures, we can find the descriptions on writing errors, including various types of paragraphia, syntactic errors and omission of letters. Although most of writing errors were observed in context with aphasia and/or dementia, we reported two case of ALS with isolated agraphia. This experience suggests that isolated agraphia could appear independently of existence of aphasia and/or dementia, and that isolated agraphia could be an early manifestation of ALS-D. We consider that isolated agrapahia might be associated dysfunction of the posterior part in the middle or inferior frontal lobes of the dominant hemisphere. In patients with ALS especially bulbar-onset, assessment of writing should be very important to assess language function masked under impaired speech.
