Analysis of spontaneous speech in Parkinson's disease by natural language processing

• Published in: Parkinsonism & related disorders Vol. 113; p. 105411
• Main Authors: Yokoi, Katsunori, Iribe, Yurie, Kitaoka, Norihide, Tsuboi, Takashi, Hiraga, Keita, Satake, Yuki, Hattori, Makoto, Tanaka, Yasuhiro, Sato, Maki, Hori, Akihiro, Katsuno, Masahisa
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2023
• Subjects: Linguistic analysis; Natural language processing; Parkinson's disease; Part-of-speech; Spontaneous speech; Spontaneous speech; Natural language processing; Parkinson's disease; Linguistic analysis; Part-of-speech
• ISSN: 1353-8020; 1873-5126; 1873-5126
• DOI: 10.1016/j.parkreldis.2023.105411

Patients with Parkinson's disease (PD) encounter a variety of speech-related problems, including dysarthria and language disorders. To elucidate the pathophysiological mechanisms for linguistic alteration in PD, we compared the utterance of patients and that of healthy controls (HC) using automated morphological analysis tools. We enrolled 53 PD patients with normal cognitive function and 53 HC, and assessed their spontaneous speech using natural language processing. Machine learning algorithms were used to identify the characteristics of spontaneous conversation in each group. Thirty-seven features focused on part-of-speech and syntactic complexity were used in this analysis. A support-vector machine (SVM) model was trained with ten-fold cross-validation. PD patients were found to speak less morphemes on one sentence than the HC group. Compared to HC, the speech of PD patients had a higher rate of verbs, case particles (dispersion), and verb utterances, and a lower rate of common noun utterances, proper noun utterances, and filler utterances. Using these conversational changes, the respective discrimination rates for PD or HC were more than 80%. Our results demonstrate the potential of natural language processing for linguistic analysis and diagnosis of PD. •Spontaneous speech of patients with Parkinson's diseases (PD) was analyzed.•PD patients spoke less morphemes on one sentence than the healthy controls.•PD patients had a higher rate of verbs and a lower rate of noun than controls.•Discrimination accuracy rates using identified language items were more than 80%.