Abstract
Category:
Other; Midfoot/Forefoot
Introduction/Purpose:
Charcot-Marie-Tooth (CMT) disease is an inherited peripheral neuropathy known to cause progressive sensory and motor impairment. Patients often develop foot structure abnormalities, including pes cavus, due to intrinsic muscle weakness. These deformities, paired with the disease’s typical sensory and motor symptoms, can increase the risk of falls. Ankle foot orthoses (AFOs) are commonly used with the intent of reducing fall risk and restoring a more normal gait. The Timed Up and Go (TUG) test is widely used as a clinical screening tool to identify patients at risk of falling. No previous study has applied the TUG test in the setting of CMT fall risk assessment. The purpose of this study was to assess the overall predictive value of TUG on fall risk in CMT.
Methods:
Existing data from patients seen at the at the University of Iowa Hospitals and Clinics, as part of research with the Inherited Neuropathy Consortium (INC), were used for this investigation. Patients in the INC return to clinic on an annual basis and data from each patient’s most recent evaluation were included for analysis. All CMT sub-types were included. Clinical outcome measures were taken from the CMT Functional Outcome Measure (CMT-FOM) and the CMT Health Index (CMT-HI). Timed up and go (TUG) and patient reported ankle-foot orthoses (AFO) use was recorded as part of the CMT-FOM. The CMT-HI provides patient perspective on the impact of various health related topics, including difficulty getting up from the floor or ground, falling, and difficulty rising from a seated position. Kruskal-Wallis and Wilcoxon Rank Sum tests were utilized for statistical analysis and pair-wise group comparisons.
Results:
In total, 126 patients of 4,971 available records were included for analysis. The remainder were excluded due to missing data, unconfirmed CMT diagnosis, or statistical outliers. TUG scores ranged from 3.4s to 26.0s (mean 9.70s). Responses to the CMT-HI Falls question included no effect, little effect, moderate effect, and severely effecting, and poorer responses were correlated with a slower average TUG (p< 0.0001). Participants who reported AFO use had a average TUG score of 11.29 seconds while non-users averaged 10.0 seconds (p=0.0015). 117/126 (93%) patients reported foot deformity: 106 pes cavus, 6 pes planus, 5 “other”, 7 reported none, and 2 unreported. Of the 117 with reported deformities, those with pes planus averaged a TUG of 9.76 seconds compared to 9.45 seconds with pes cavus.
Conclusion:
This is the first study to identify a significant correlation between patient-reported fall risk and average TUG in CMT patients. This observation of slower TUG times in individuals with greater fall risk is consistent with findings available for other at-risk falls populations, such as stroke patients. The most predominant deformity was pes cavus. However, neither the presence nor absence of foot deformities showed a substantial difference in TUG results. Patients who wore Ankle-foot orthoses had, on average, slower times in the TUG test than non-users. This is likely due to greater a dependency on AFOs with increased disease progression.
