Functional correlates of gait and balance difficulty in essential tremor: Balance confidence, near misses and falls

Background: Although a mild objective abnormality of gait and balance has been observed in essential tremor (ET) cases in research settings, the clinical significance of this finding for patients is far from clear. In this study, we assessed whether ET patients subjectively experience more gait difficulty, more falls or near misses than controls. Methods: Activities-specific Balance Confidence (ABC) scores were obtained in 59 ET cases (15 with head tremor and 44 without head tremor) and 82 controls enrolled in a clinical-epidemiological study. Results: ABC scores were lower in ET cases than controls (61.8 +/- 27.7 vs. 70.3 +/- 28.1, p = 0.035) of similar age (71.2 +/- 14.6 years vs. 71.6 +/- 0.8 years), indicating significantly lower balance confidence in cases. The lowest scores (51.4 +/- 26.9) were observed in cases with head tremor (p = 0.02). Near misses in the past year were the highest in cases with head tremor (67.3 +/- 112.1) and lowest in controls (6.1 +/- 33.3, p = 0.008). The proportion who had had >= 5 near misses or falls in the past year was 11(13.4%) for controls, 8 (18.2%) for cases without head tremor and 6 (40.0%) for cases with head tremor (p = 0.048). For the ABC score, we created a receiver operating curve (ROC) curve and optimal cut-off score to differentiate between our two most different groups, namely, ET with head tremor and controls. Using this cut-off (<= 67), sensitivity and specificity were moderate. Conclusions: ET patients experience a loss of confidence in balance. The subgroup of patients with head tremor experienced the most gait and balance difficulty, with nearly one-in-two having had multiple near misses or falls during the previous year. (C) 2011 Elsevier B.V. All rights reserved.