30 November 2012
Lieberman A, Dhanani S, Dhall R, Pan D
Background: Balance difficulty is a major contributor to falls in Parkinson's disease (PD). However, the new Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor examination contains only one subtest – postural instability – and it is only 3% of the total that assesses balance. There are several balance scales, but they were not developed for PD and they do not complement the MDS-UPDRS. There is a need for a quick and easy-to-use balance scale in PD and one that complements the MDS-UPDRS.
Methods: The Barrow Neurological Institute (BNI) balance scale was developed as a complement to the MDS-UPDRS and was used to evaluate the risk of falling in 53 PD patients. There were nine patients who fell three times per month ("fallers"). The BNI scale was compared with the widely used Tinetti scale. The Tinetti scale has 16 subtests; the BNI scale has five.
Results: The nine fallers had a significantly longer PD duration, a higher MDS-UPDRS score, a higher (worse) BNI balance score, and a lower (worse) Tinetti score compared to 44 nonfallers. Fallers were significantly more impaired on the MDS-UPDRS subtest of postural stability and on the BNI scale. A BNI scale score ≥ 13 had a sensitivity of 100% and a specificity of 88.6% in identifying fallers, whereas a Tinetti scale score ≤ 18 had a sensitivity of 55.6% and a specificity of 95.5% in identifying fallers. The BNI scale with five subtests is easier to perform than the Tinetti with 16 subtests.
Conclusion: The BNI balance scale is more sensitive and specific in predicting falls than the Tinetti. It is a useful adjunct to the MDS-UPDRS.