Language in ALS/FTLD

Abstract

In the 1990s, the concept of frontotemporal lobar degeneration (FTLD) was proposed as a clinicopathological entity preferentially involving the frontotemporal lobes, and recent pathological findings have suggested a linkage of FTLD with ALS. FTLD includes frontotemporal dementia (FTD), reflecting behavioral changes, and progressive non-fluent aphasia (PNFA) and semantic dementia (SD) as language disorders. Although language problems appear to have become of interest relatively recently, an historical Japanese account (1893) written by Watanabe described aphasia in bulbar-onset ALS. This report is entitled "A patient who manifested cortical motor aphasia concurrently with bulbar palsy and progressive muscular atrophy", and is the first case report of aphasia published in Japan. Thus, language problems in ALS may have been overlooked for many years. We have reported that ALS patients frequently show omission and paragraphia of kana letters, and syntactic errors in writing, and that these observations differ across patients. We also showed double dissociation between errors in kana and kanji characters in some patients, with preferential involvement of the frontotemporal lobes and frontal- and temporal-lobe predominance for kana and kanji, respectively. We also showed that the writing errors can appear as agraphia without aphasia.