A new rating instrument to assess festination and freezing gait in Parkinsonian patients

Mov Disord. 2010 Jun 15;25(8):1012-8. doi: 10.1002/mds.22993.


Festination and freezing of gait (FOG) are sudden episodic inabilities to initiate or sustain locomotion mostly experienced during the later stages of Parkinson's disease (PD) or other higher-level gait disorders. The aim of this study was to develop a clinical rating instrument for short-interval rating of festination and FOG. Foot movements of 33 patients were video taped and rated during 12 episodes in a standardized course on a four-level interval scale according to severity. Motor blocks were provoked in four situations and by three levels of dual-tasking (tasks). Addition of the item scores produced a FOG score. The assessment requires less than 15 min. The inter-rater and re-test reliability of the FOG score is high (Kendall kappa = 0.85-0.92, P < 0.0001). Variability of the item scale due to situations and tasks can be attributed to unidimensional group factors (Cronbach's alpha 0.84 and 0.94). Group comparisons and a logistic regression model show significant effects for both situations and tasks on the item scale (Friedman test: "situation": P < 0.0001, "task": P < 0.0001). Six patients with PD have significantly different scores during mobile (practical ON; 6.2 +/- 3.9) and immobile (practical OFF; 15.8 +/- 4.6) medication states (P < 0.05). The FOG score correlates with the 10 m number of steps (rho = 0.58; P = 0.001) and with the self-evaluation of FOG (rho = 0.51; P < 0.01). Our results encourage the further use of the FOG score to evaluate festination and FOG.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Disability Evaluation*
  • Female
  • Freezing Reaction, Cataleptic / physiology*
  • Gait Disorders, Neurologic / diagnosis*
  • Gait Disorders, Neurologic / etiology*
  • Humans
  • Logistic Models
  • Male
  • Middle Aged
  • Parkinsonian Disorders / complications*
  • Reproducibility of Results
  • Retrospective Studies
  • Sensitivity and Specificity
  • Severity of Illness Index*