Lexical Retrieval Performance in Patients with Normal Pressure Hydrocephalus and Parkinson’s Disease

Objectives: This study aimed to investigate lexical retrieval performance in patients with similar patterns but different central nervous system degenerative diseases, specifically normal pressure hydrocephalus (NPH) and Parkinson’s disease (PD).Methods: A lexical retrieval task was performed on 14 patients with NPH, 14 patients with PD, and 14 healthy elderly subjects (HE) to compare their correct response scores, reaction times, and error types, and the Korean-Boston naming test (K-BNT) was additionally performed to determine the validity of the lexical retrieval task.Results: First, there was no significant difference in scores between the three groups on the K-BNT. Second, the scores of the NPH and PD groups were significantly lower than the HE group on the lexical retrieval task. Third, only the NPH group was significantly slower than the HE group in the reaction time on the lexical retrieval task. Fourth, the error type analysis showed that the NPH group made significantly more semantic and nonword errors and the PD group made significantly more semantic errors than the HE group. Fifth, the correlation analysis showed a significant static correlation between K-BNT and the lexical retrieval task scores with a correlation coefficient of .721.Conclusion: We suggest that the lexical retrieval task may be useful in the screening and differential diagnosis of patients with NPH and PD.