Differential gait disturbances in patients with Parkinson's disease and normal pressure hydrocephalus

Gait disturbances are a key symptom in normal pressure hydrocephalus (NPH) and Parkinson's disease (PD). We employed instrument-supported gait analysis to characterize commonalities and differences in gait patterns among PD and NPH patients, as well as gait changes following disease-specific interventions (i.e., spinal tap and dopaminergic medication).

Gait and balance analyses were conducted i) before and after NPH patients (n = 19) received a spinal tap, and ii) before and after PD patients (n = 19) received soluble dopaminergic medication. Change scores were calculated relative to each patient's baseline performance. Group differences were analyzed using independent sample t-tests or Mann-Whitney U tests and within-group changes using paired sample t-tests or Wilcoxon signed-rank tests.

Static postural control (i.e., balance) did not differ between patient groups, but dynamic postural control did, with PD patients showing significantly reduced mediolateral sway and gait width compared to NPH patients. These parameters did not change after disease-specific interventions. For gait dynamics, PD patients demonstrated significantly higher values in pace and force parameters, which improved significantly in both groups following intervention. Finally, gait regularity showed lower variability and better rhythm-related parameters in PD patients compared to NPH patients, along with differential changes after interventions.

Except for static postural control (i.e., balance), instrument-supported gait analysis revealed several characteristic gait differences between PD and NPH patients. Variability and rhythm, reflecting gait regularity, were best suited to differentiate gait disturbances in patients with PD and NPH.