Swallowing problems in Parkinson disease: frequency and clinical correlates.

ABSTRACT

BACKGROUND: Changes to the efficiency and integrity of swallowing mechanisms are inevitable in Parkinson disease (PD); however, it remains unclear how many people with PD are at risk of dysphagia. The aim of this study was to establish the frequency of impaired swallowing in people with PD and the relationship between swallowing performance and indicators of disease progression. METHODS: A community-based and hospital-based cohort of 137 individuals with PD were asked to drink 150 ml of water as quickly as possible while in an 'off drug' state. RESULTS: Thirty-one (23%) patients could not completely drink the full 150 ml. Swallowing rate (ml/sec) fell to more than 1 SD below published norms for 115 (84%) patients and to more than 2SD below for 44 (32%) individuals. There were moderate correlations between rate of swallowing and disease severity, depression and cognition, but not between swallowing speed and disease duration. There was poor correlation between subjective reports of dysphagia and performance on the water swallow test. CONCLUSIONS: Swallowing problems are frequent in PD. Self-report of 'no difficulty' is not a reliable indicator of swallowing ability. Studies employing more-objective assessment of aspiration risk to compare with water swallow test performance are advocated.