Detecting and Predicting Balance Decline in Parkinson Disease: A Prospective Cohort Study

Background: The natural progression of balance decline in individuals with Parkinson disease (PD) is not well understood. Objectives: We aimed to: 1) compare the utility of three standardized clinical measures for detecting balance decline over 1-year, 2) identify components of balance susceptible to decline, and 3) identify factors useful for predicting future balance decline. Methods: Eighty people with PD (59% male; mean age 68.2 +/- 9.3; Hoehn & Yahr range I-IV) completed Balance Evaluation Systems Test (BESTest), Mini-BESTest, and Berg Balance Scale (BBS) assessments. Baseline predictor variables included the MDS-UPDRS III sub-score, presence of freezing, 6-month fall history, age, gender, and physical activity. Balance and MDS-UPDRS III assessments were repeated at 6 (n = 51) and 12 months (n = 44). Results: BESTest and Mini-BESTest score declined over 6 and 12 months (P < 0.01). Postural responses, stability limits, and sensory orientation were most susceptible to decline. BBS score did not change (P > 0.01). MDS-UPDRS III score was unchanged over 6 months (P > 0.01), but declined over 12 months (P < 0.01). Change in BESTest score over 6 months was related to baseline MDS-UPDRS III, H&Y, freezing, and fall history (P < 0.05). Change in BESTest score over 12 months was related to baseline MDS-UPDRS III and freezing (P < 0.05). Change in Mini-BESTest over 12 months was related to baseline MDS-UPDRS III and age (P < 0.05). Conclusions: The BESTest and Mini-BESTest were responsive to balance decline in individuals with PD and helped to identify decline in underlying balance components. Disease severity and freezing most consistently predicted balance decline in persons with PD.