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

Abstract

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.

Keywords:

• Amyotrophic lateral sclerosis
• writing errors
• Western Aphasia Battery
• perfusion SPECT
• angular gyrus

Acknowledgements

The authors are grateful to Dr. Hideharu Furumoto, Department of Neurology, National Hospital Organization Chiba Medical Center, for helpful discussions and comments on the manuscript. Authors would also want to thank Department of Radiology, Chiba University Hospital for technical supports. We thank the reviewers for their attentive reading and suggestions to improve the quality of this manuscript.

Declaration of interest

T. Sakurai, S. Hirano, M. Abe, Y. Uji, H. Suzuki, K. Shimizu, M. Suzuki, Y. Nakano, A. Ishikawa, K. Kojima, K. Shibuya, A. Murata and Prof. S. Kuwabara have nothing to disclose. Normal images were supported by Nihon Medi-Physics Co. Ltd. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.