Freezing of gait is associated with cognitive impairment in patients with Parkinson disease

Objective: To explore whether the cognitive impairment is correlated with freezing of gait (FOG) in patients with Parkinson disease (PD).

Methods: A total of 186 patients with Parkinson disease (104 patients with FOG and 82 patients with no clinical history of freezing behavior) and 125 healthy individuals were selected for this study. Neuropsychological assessments, including the scales for outcomes in Parkinson disease cognition, unified Parkinson's disease rating scale, and Hamilton depression/anxiety rating scale etc., were applied to evaluate the patients'cognitive functioning.

Results: We found that the scores of Unified Parkinson's Disease Rating Scale (UPDRS) were significantly higher among PD patients with FOG, compared with non-FOG group. We also showed that Mini-Mental State Examination score (MMSE) was lower among subjects with FOG than in patients without FOG. Patients with FOG displayed lower Scales for OUTCOMES: in Parkinson's Disease Cognition (SCOPA-COG) score than non-FOG patients. In addition, significant higher Hamilton Anxiety Rating Scale (HAMD) scores were found in patients with FOG than patients without FOG. Moreover, disease duration, stage of the disease, the severity of motor symptom, increased depressive and anxiety complaints measured by FOG questionnaire were significantly associated with severity of FOG. Meanwhile, we also found that the score of Freezing of Gait Questionnaire (FOGQ) score was negatively correlated with MMSE.

Conclusion: Our results demonstrated that FOG is related to impaired cognitive functions in PD patients with FOG. The understanding of impaired cognitive functions in PD patients with FOG can provide evidences for possible therapeutic interventions.