Predicting Falls in Parkinson Disease: What Is the Value of Instrumented Testing in OFF Medication State?

Abstract

BackgroundFalls are a common complication of advancing Parkinson's disease (PD). Although numerous risk factors are known, reliable predictors of future falls are still lacking. The objective of this prospective study was to investigate clinical and instrumented tests of balance and gait in both OFF and ON medication states and to verify their utility in the prediction of future falls in PD patients.MethodsForty-five patients with idiopathic PD were examined in defined OFF and ON medication states within one examination day including PD-specific clinical tests, instrumented Timed Up and Go test (iTUG) and computerized dynamic posturography. The same gait and balance tests were performed in 22 control subjects of comparable age and sex. Participants were then followed-up for 6 months using monthly fall diaries and phone calls.ResultsDuring the follow-up period, 27/45 PD patients and 4/22 control subjects fell one or more times. Previous falls, fear of falling, more severe motor impairment in the OFF state, higher PD stage, more pronounced depressive symptoms, higher daily levodopa dose and stride time variability in the OFF state were significant risk factors for future falls in PD patients. Increased stride time variability in the OFF state in combination with faster walking cadence appears to be the most significant predictor of future falls, superior to clinical predictors.ConclusionIncorporating instrumented gait measures into the baseline assessment battery as well as accounting for both OFF and ON medication states might improve future fall prediction in PD patients. However, instrumented testing in the OFF state is not routinely performed in clinical practice and has not been used in the development of fall prevention programs in PD. New assessment methods for daylong monitoring of gait, balance and falls are thus required to more effectively address the risk of falling in PD patients.

Falls in Parkinson's disease: A complex and evolving picture

“…By comparison, the instrumented TUG provides measures of duration and quality of each TUG subtask, outperforming TUG itself in terms of discriminating fallers from nonfallers and identifying mild impairment and those at risk of falls . Results from a small cohort patients with PD show that 2 instrumented TUG–derived metrics (increased stride time variability in the OFF medication state and faster walking cadence) were the most significant predictors of future falls over 6 months, superior to more traditional clinical predictors …”

“…[55][56][57][58] Results from a small cohort patients with PD show that 2 instrumented TUG-derived metrics (increased stride time variability in the OFF medication state and faster walking cadence) were the most significant predictors of future falls over 6 months, superior to more traditional clinical predictors. 59 Where Should We Be Heading?…”

Gait initiation is impaired in subjects with Parkinson’s disease in the OFF state: Evidence from the analysis of the anticipatory postural adjustments through wearable inertial sensors

“…Hence, symptoms are typically improved by replacing dopamine with L-dopa or dopaminergic agonists [4–7], therefore, measuring APAs in the ON state might not be representative of motor impairments.…”

Investigation of factors impacting mobility and gait in Parkinson disease

“…All except one of these previous studies measured participants while on anti-parkinson medication, and the single study testing ‘off’ medication included a relatively small sample (Lord et al, 2010). While medications are known to impact gait and mobility as well as some of these previously identified factors (Hoskovcová et al, 2015), it is unclear whether different factors may be better predictors in the ‘off’ medication state when motor function is worse. Further, only one study previously examined balance as a potential predictive factor for gait or mobility in PD on medication (Falvo & Earhart, 2009), but predictive value was only assessed for the six minute walk test distance.…”