Clinical correlates of repetitive speech disorders in Parkinson's disease

This study aimed to explore clinical correlates of repetitive speech disorders in patients with Parkinson's disease (PD).

This study investigated speech function (Assessment of Motor Speech for Dysarthria and Stuttering Severity Instrument-3), motor function (Unified Parkinson's Disease Rating Scale III [UPDRS-III] and UPDRS-IV), cognitive function (Mini-Mental State Examination [MMSE], Montreal Cognitive Assessment [MoCA], Stroop color-word test, verbal fluency, digit span tests, and line orientation), and activities of daily living of 113 PD patients. Comparison between groups (independent t-tests, Mann-Whitney U tests, or χ² test) and linear regression analyses were performed to determine clinical correlates of repetitive speech disorders.

Totally, 65 patients (57.5%) had repetitive speech disorders. Patients with repetitive speech disorders had significantly worse UPDRS-III (P = .049), MoCA (P = .030), and speech function and higher levodopa equivalent daily dose (LEDD; P = .031) than those without repetitive speech disorders. Males were significantly predominant in patients with repetitive speech disorders (64.6%) compared to those without repetitive speech disorders (18.7%; P < .001). The univariate and subsequent multiple linear regression analyses revealed that the severity of repetitive speech disorders significantly correlated with gender (P < .001), MoCA (P = .006), and speech variables (abnormal rate, P = .007; imprecise consonants, P = .043), independent from disease duration, UPDRS III, and LEDD.

PD patients with repetitive speech disorders had worse motor, cognitive, and speech functions than those without repetitive speech disorders. The most influential factor for repetitive speech disorders might be male gender.