Dysfunction of the left angular gyrus may be associated with writing errors in ALS.

Background: Language dysfunction is a feature of cognitive impairment in amyotrophic lateral sclerosis (ALS) that may compromise communication. Objective: To elucidate language dysfunction in patients with ALS and its relationship with other neuropsychological tests and to identify the brain regions associated with this dysfunction using perfusion image. Methods: Overall, 37 patients with ALS were included in this study. Their neuropsychological function was investigated using the Western Aphasia Battery (WAB), Frontal Assessment Battery and Behavioral Assessment of the Dysexecutive Syndrome. N-isopropyl-p-[123I] iodoamphetamine single-photon emission computed tomography was used to examine regional cerebral blood flow and its relationship with WAB scores was investigated using multiple regression analyses, controlled for age, sex and years of education. Results: Frequency of language abnormality in ALS was 8.5% for spontaneous speech, 25.7% for auditory verbal comprehension, 8.8% for repetition, 14.7% for naming, 17.6% for reading and 51.4% for writing. The writing error was mainly omission and substitution of kana letters. Executive tests were correlated with naming (r > 0.5, p < 0.001) and reading (r > 0.4, p < 0.01) scores. With respect to the writing sub-test, positive perfusional relationship was only detected in the left angular gyrus. Conclusions: The left angular gyrus is the region associated with the writing errors observed in ALS.