Quantitative gait analysis in parkin disease: Possible role of dystonia.

INTRODUCTION: Parkin disease (PARK2, OMIM 602544) is an autosomal-recessive early-onset parkinsonism characterized by an early occurrence of lower limb dystonia. The aim of this study was to analyze spatiotemporal, kinematic, and kinetic gait parameters in patients with parkin disease in the OFF and ON conditions compared to healthy age-matched controls.
METHODS: Fifteen patients with parkin disease and 15 healthy age-matched controls were studied in a gait analysis laboratory with an integrated optoelectronic system. Spatiotemporal, kinematic, and kinetic gait parameters at a self-selected speed were recorded in the OFF and ON conditions. A jerk index was computed to quantify the possible reduction of smoothness of joint movements.
RESULTS: Compared to controls, parkin patients had, either in the OFF or in the ON conditions, significant reduction of walking velocity, increased step width, and decreased percentage of double support. Kinematic analysis in both conditions showed: increased ankle dorsiflexion and knee flexion at the initial contact; maximal flexion and increased range of motion in mid stance; increased hip flexion and max extension in stance at pelvis; and increased mean tilt antiversion. Kinetics showed increased hip and knee power generation in stance in either condition. The jerk index was increased at all joints both in OFF and ON. There were no correlations between individual gait parameters and clinical ratings.
CONCLUSION: Parkin patients have an abnormal gait pattern that does not vary between the OFF and the ON conditions. Variations recorded with instrumented analysis are more evident for kinematic than kinetic parameters at lower limbs. Severity of dystonia does not correlate with any individual kinematic parameter.