Assessment of Balance in Adults with Friedreich’s Ataxia
Purpose/Hypothesis: Balance deficits are common sequelae of Friedreich’s Ataxia (FA), yet, there are no standardized assessments to specifically assess balance in the FA population. Clinical rating scales for ataxia include balance items, but do not focus on balance assessment. Balance deficits are related to gait ataxia, and worsening balance and gait impairment may contribute to falls and loss of ambulation over time. The purpose of this study was to investigate changes in balance over time in adults with FA, utilizing balance specific assessments, including the Berg Balance Scale (BBS).
Number of Subjects: 16
Materials/Methods: A longitudinal research design was applied to investigate changes in balance in 8 subjects with genetically confirmed FA (29.4 ± 9.0 yrs.) utilizing the BBS and the Biodex Balance System’s Limits of Stability (LOS) test at baseline, 6 months, 12 months and 24 months; 8 healthy, matched control subjects (29.6 ± 9.1 yrs.) underwent the same tests at baseline and 12 months. A linear mixed effect (LME) model was applied to determine whether FA subjects’ BBS or LOS scores demonstrated a significant linear change from baseline to 24 months. Paired t-tests were conducted to assess whether control subjects’ balance measures changed over 12 months.
Results: Average disease duration of FA subjects was 10 years (range 6-16 yrs.). Control subjects attained the maximum BBS score at baseline and this did not change at 12 months. Subjects with FA exhibited a decline in mean BBS scores of 7% at 12 months and 18% at 24 months, at which time the mean BBS score was 36. Six of 8 FA subjects self-reported at least one fall per month. In the FA group, the LME model revealed a significant linear change in BBS scores (0.27 average unit decrease per month, β=-0.266, p=0.001) and in LOS backward directional control scores (0.71 average unit decrease per month, β=-0.713, p=0.024) over 24 months. No significant change in either time to complete the LOS test or overall directional control scores were observed. In the control group, no significant changes in LOS scores were apparent, with the exception of an increase in the LOS forward directional control score (t=-3.706, p=0.018).
Conclusions: Adults with FA demonstrated a significant decline in BBS scores, with 5 of 7 subjects falling below the BBS cut-off score for high falls risk (40/56) by 24 months. Although subjects with FA did not show a significant decline in LOS overall directional control scores, they did demonstrate declining backward directional control scores indicative of a decreased ability to control center of pressure movement in a backward direction.
Clinical Relevance: Adults with FA demonstrate worsening balance and increased falls risk over time. In this study, the BBS proved to be a sensitive assessment to detect changes in balance in adults with FA. This information may benefit clinicians who examine balance in people with FA, prior to implementing interventions to prevent falls and activity limitations of balance.
American Physical Therapy Association Combined Sections Meeting (APTA-CSM)
Stephenson, Jeannie, Seok Hun Kim, Clifton Gooch, Kelly L. Sullivan, Israt Jahan, Theresa A. Zesiewicz.
"Assessment of Balance in Adults with Friedreich’s Ataxia."
Epidemiology Faculty Presentations.