Investigation of the Impact of Motor, Nonmotor, Cognitive, and Psychometric Features on Freezing of Gait in Parkinson's Disease

There are still debates regarding the pathophysiology of freezing of gait (FOG) in Parkinson's disease (PD). This study aims to investigate the potential contribution of the nonmotor symptoms in the pathophysiology of FOG. This was a cross-sectional observational cohort study where we enrolled all consecutive PD patients who applied to our movement disorders outpatient clinics at Etlik City Hospital, Ankara, Turkey, between January 2024 and August 2024. We performed comprehensive assessments including scales to evaluate both motor and nonmotor features, psychometric properties, and cognitive characteristics. In the hierarchical regression analyses, we sought to examine the contributory role of the motor, nonmotor, neuropsychological, and cognitive symptom load on FOG one by one. We included 45 PD patients with a mean age of 61.9 ± 8.6. The median disease duration was 5 years (range: 20), the median MDS-UPDRS-3-off score was 33 (range: 20.5). The comparative analyses between patients with (n = 21) and without FOG (n = 24) revealed that the scores regarding the MDS-UPDRS-1 (p = 0.04), MDS-UPDRS-3 (p = 0.00), MDS-UPDRS-3-axial subscore (p = 0.00), NMSS (p = 0.017), SMMSE (p = 0.02), forward counting (p = 0.044), backward counting (p = 0.015), JLO (p = 0.033), HAM-A (p = 0.006), and HDRS (p = 0.006) were all higher in the FOG (+) group. In the hierarchical regression analyses, the MDS-UPDRS-3-off score was the only predictive factor of FOG severity in the model evaluating the motor factors (B = 0.251, p = 0.000) and also the other models which we included the other nonmotor features one by one. Our findings showed that nonmotor symptoms, cognitive functions, and psychometric properties do not provide a contributory effect to the motor severity on the FOG severity.