Dopaminergic denervation is not necessary to induce gait disorders in atypical parkinsonian syndrome.

BACKGROUND Gait impairment is common in parkinsonian syndromes but not specific to striatonigral dysfunction. The relationship between the dopaminergic system and gait parameters is poorly understood. This cross-sectional study aimed to determine if gait measures are related to the striatal dopamine transporters distribution using [(123)I]FP-CIT SPECT in patients with parkinsonian syndromes. MATERIALS AND METHODS Twenty-four patients with gait impairment and parkinsonian syndromes without Parkinson's disease (mean age: 73.6±8.2years) were included in this study. Gait analysis during single- and dual-task condition (walking and backwards counting) and [(123)I]FP-CIT SPECT were performed within 3months of each other. Patients were visually categorized as having normal (n=14) or abnormal (n=10) [(123)I]FP-CIT SPECT. In addition, a volume-of-interest-based analysis of uptake ratios (caudate and putamen) relative to the occipital cortex and a voxelwise analysis using SPM8 were also performed. RESULTS Patients with parkinsonian syndromes and abnormal [(123)I]FP-CIT SPECT did not significantly differ in terms of spatiotemporal gait parameters from those with normal [(123)I]FP-CIT SPECT. Moreover, after correction for multiple comparisons, we did not observe any association between regional uptake ratio and spatiotemporal gait parameters for single and dual tasking. Finally, none of these parameters showed a significant association with voxelwise [(123)I]FP-CIT uptake. CONCLUSIONS Dopaminergic denervation, as measured by [(123)I]FP-CIT SPECT, is not necessary to induce alterations of spatiotemporal gait parameters during single and dual task in patients presenting with atypical parkinsonian syndromes.