Managing freezing of gait in Parkinson’s disease: a systematic review and network meta-analysis

Freezing of gait (FOG) is one of the most disabling gait disorders affecting 80% of patients with Parkinson’s disease (PD). Clinical guidelines recommend a behavioral approach for gait rehabilitation, but there is a wide diversity of behavioral modalities. The objective of this network meta-analysis was to compare the effectiveness of different behavioral interventions for FOG management in PD patients. Six databases were searched for randomized controlled trials of behavioral interventions for FOG management among PD patients from 1990 to December 2021. Bayesian network meta-analysis was used to combine both direct and indirect trial evidence on treatment effectiveness, while the surface under the cumulative ranking (SUCRA) score was used to estimate the ranked probability of intervention effectiveness. Forty-six studies were included in the qualitative synthesis. Among, 36 studies (1454 patients) of 72 interventions or control conditions (12 classes) were included in the network meta-analysis, with a mean intervention period of 10.3 weeks. After adjusting for the moderating effect of baseline FOG severity, obstacle training [SMD −2.1; 95% credible interval (Crl): −3.3, −0.86], gait training with treadmill (SMD −1.2; 95% Crl: −2.0, −0.34), action observation training (SMD −1.0; 95% Crl: −1.9, −0.14), conventional physiotherapy (SMD −0.70; 95% Crl: −1.3, −0.12) and general exercise (SMD −0.64; 95% Crl: −1.2, −0.11) demonstrated significant improvement on immediate FOG severity compared to usual care. The SUCRA rankings suggest that obstacle training, gait training on treadmill and general exercises are most likely to reduce FOG severity. Obstacle training, gait training on treadmill, general exercises, action observation training and conventional physiotherapy demonstrated immediate real-life benefits on FOG symptoms among patients with mild–moderate PD. With the promising findings, the sustained effects of high complexity motor training combined with attentional/cognitive strategy should be further explored. Future trials with rigorous research designs using both subjective and objective outcome measures, long-term follow-up and cost-effective analysis are warranted to establish effective behavioral strategies for FOG management.