Comparison of gait patterns and functional measures between Charcot-Marie-Tooth disease type I and II in children to young adults

Introduction: Charcot-Marie-Tooth (CMT) disease is an inherited peripheral neuropathy that causes progressive distal extremity nerve degeneration and muscle atrophy which can negatively impact function, gait and quality of life. The purpose of this study was to determine if differences exist in gait patterns, clinical examination and functional measures between CMT type I (CMT1) and type II (CMT2) in childhood to young adults. It was hypothesized that individuals with CMT2 would present with greater ankle weakness, increased and/or prolonged ankle dorsiflexion in stance during gait and demonstrate greater disease severity on the CMT Pediatric Scale (CMTPedS) compared to CMT1.

Methods: Twenty-seven individuals diagnosed with CMT1 or CMT2 underwent three-dimensional gait analysis, clinical examination and evaluation of disease severity using the CMTPedS. Subjects groups were divided based on CMT type: CMT1 (n = 20) and CMT2 (n = 7).

Results: CMT2 group presented with a trend towards increased plantar flexion weakness compared to CMT1 of 61.1 ± 58.1 N to 137.9 ± 51.4 N (p < 0.012), respectively. CMT2 presented with significantly decreased dorsiflexion strength, 31.9 ± 30.9 N, compared to CMT1, 80.4 ± 37.4 N, (p < 0.0052) which negatively influenced gait patterns in CMT2. Associated gait findings demonstrated CMT2 group with significantly decreased peak ankle power generation in stance compared to CMT1 (1.46 ± 0.39 W/kg to 3.13 ± 0.98 W/kg respectively) (p < 0.0001). CMT1 was more likely to demonstrate a dorsiflexion moment in loading response than CMT2. There was a consistent trend of a higher score and therefore greater disease severity for CMT2 based on CMTPedS.

Conclusion: Study results suggest that at a given age, individuals with CMT2 have greater limitations in terms of gait function and disease severity than individuals with CMT1. Overall the CMT2 was shown to have greater gait limitations at the ankle during stance and swing with associated compensatory mechanisms at the knee and hip in swing.