RP302 - Optimizing Postural Stability Assessment

Abstract:
In this session, the assessment of postural stability and new paradigms that can potentially improve the diagnosis of balance dysfunction and fall risk are discussed in a healthy cohort and a cohort with traumatic brain injury (TBI).

Summary:

Background:
Ineffective postural control contributes to imbalance and unsteadiness and may result in falls if an individual is destabilized. Falls are especially prevalent in the aging population and those with TBI, resulting in costs exceeding $50 billion directly related to falls in 2015 alone. The sensory organization test (SOT) is the gold standard for assessing postural stability. When interpreting SOT results, equilibrium scores are derived from the relationship between an individual’s sway and a fixed theoretical limit of stability (tLOS). However, determining an individual’s postural stability and fall risk based on a one-size-fits-all tLOS has the potential to overestimate functional equilibrium scores and in turn, underestimate fall risk.

Objective:
To investigate whether personal LOS (pLOS) measured from healthy adults is different from the tLOS, and whether SOT equilibrium scores are significantly different when calculated based on pLOS instead of tLOS in healthy adults, and determine if calculation of a personalized SOT (pSOT) based on the pLOS is an accurate marker for fall-risk in a group of TBI patients.

Design:
Two groups were analyzed: 1) 68 healthy volunteers comprising three age groups: young (18-39), middle-aged (40-64), and elderly (65-80), with equal numbers of males and females. All had a normal age-based hearing and a negative history of vertigo and imbalance. 2) Data from 117 patients with TBI aged 18-86 years (M=44.5, SD=6.7) were evaluated. Both groups were assessed using SOT and LOS. Medical records were reviewed for the occurrence of falls in the succeeding 1-5 years for the TBI group. SOT scores derived using pLOS and tLOS were compared to determine which method is more closely associated with the recorded fall history.

Results:
The pLOS from the healthy volunteers was consistently and significantly lower than tLOS across both sexes and all age groups (p < .0005); however, no aging effect was observed. Subsequently, SOT scores calculated using pLOS were significantly lower and more variable than scores derived using tLOS. The pLOS of the TBI group was significantly lower than that of the healthy cohort (p < .0005) and subsequently pSOT scores were also significantly lower. Abnormal postural stability was identified in 7 additional patients with TBI using the pSOT. Further analysis of the sensitivity and specificity of pSOT in identifying fall-risk in the TBI patients is currently underway.