Abstract Details

Title Apraxia as a Catalyst of Freezing of Gait in Parkinson’s Disease: Insights From Longitudinal Models

Topic Movement Disorders

Presentation(s) P9 - Poster Session 9 (5:00 PM-6:00 PM)

Poster/Presentation
Number 17-001

Objective To evaluate whether the presence of ideomotor apraxia (IMA) is associated with increased risk of developing freezing of gait (FOG) in patients with Parkinson’s disease (PD), using cross-sectional, longitudinal, and survival analyses.

Background IMA and FOG may share overlapping pathophysiological mechanisms involving disrupted fronto-parieto-striato-mesencephalic circuits. Both reflect failures to translate motor intention into automatic execution, interfering with the integration of goal-directed and habitual control, contributing to impaired movement initiation and sequencing in PD.

Design/Methods A cross-sectional and longitudinal study was conducted using data from the Parkinson’s Progression Markers Initiative (PPMI; www.ppmi-info.org). Approximately 3,596 PD patients with serial clinical records were included. Gait apraxia was defined as a binary variable (APRAXIA_BIN), and FOG was assessed using three outcomes: FOG_BIN, FOG_UPDRS-II, and FOG_UPDRS-III. Cross-sectional analyses included 2×2 contingency tables, χ²/Fisher’s tests, and odds ratios (OR) with 95% confidence intervals. Mixed-effects logistic models with random intercepts per patient were fitted, accounting for time since baseline. Kaplan–Meier and Cox survival analyses evaluated FOG onset. Models were adjusted for age, sex, and follow-up duration.

Results Among 3,596 patients, ideomotor apraxia was observed in ~40% during follow-up. In cross-sectional analyses, apraxia was consistently associated with greater FOG prevalence across all definitions subjective (FRZGT12M), UPDRS-II, and UPDRS-III with ORs ranging from 3.49 to 8.04 (all p < 0.000001), strongest with clinician-rated measures (UPDRS-III). In longitudinal models, apraxia remained a significant predictor of FOG via UPDRS-III (OR = 4.57; 95% CI: 2.58–8.10), while time also increased risk (OR per year = 1.33; 95% CI: 1.23–1.44). Kaplan–Meier curves showed significantly reduced FOG-free survival in patients with apraxia (log-rank p < 0.0001).

Conclusions IMA is associated with an approximately fivefold increased risk of developing FOG in PD. These findings suggest that apraxia may serve as an early clinical marker of fronto-subcortical dysfunction, highlighting its prognostic utility in clinical settings.

Authors/Disclosures
Daniel Martinez-Ramirez, MD (Oncare) PRESENTER	Dr. Martinez-Ramirez has nothing to disclose.
Francisco A. Luna-Rangel, MD, BS	Dr. Luna-Rangel has nothing to disclose.
Karen I. Pozo, MBBS	Dr. Pozo has nothing to disclose.
Erick Alejandro Barajas Llamas, MD	Dr. Barajas Llamas has nothing to disclose.
Brenda Gonzalez, Jr., MD	Dr. Gonzalez has nothing to disclose.
Kenny P. Gonzalez Aguilar, MD	Dr. Gonzalez Aguilar has nothing to disclose.