Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies

Department Chair

John Cavenagh, MBA, PhD, PA-C


OBJECTIVE: The objective of this selective EBM review is to determine whether or not botulinum toxin injections improve the freezing of gait (FOG) episodes experienced by patients diagnosed with Parkinson’s disease (PD).

STUDY DESIGN: This review is based on three randomized controlled trials published in 2004, 2005, and 2007. All of the studies compared the efficacy as well as safety of using botulin toxin injections to treat FOG episodes experienced by PD patients.

DATA SOURCES: All articles used were published in English, in peer-reviewed journals, and were found using PubMed searches.

OUTCOMES MEASURED: For all studies, the safety and efficacy of botulin toxin injections in the legs of patients with PD who experience FOG episodes was evaluated using clinical assessment as well as questionnaires such as the United Parkinson’s Disease Rating Scale (UPDRS). The post-treatment measurements were compared to pre-treatment baseline assessments to determine any improvements.

RESULTS: Leg weakness, skin changes, and increase in number of falls were a few adverse reactions that occurred after treatment with botulinum toxin injections. The three studies completed by Wieler, Fernandez, and Gurevich had statistically insignificant results.

CONCLUSION: All three of the RCTs that were evaluated did not demonstrate a statistically significant difference after the patients received botulinum toxin injections. Botulinum toxin injections are not proven to be effective in the treatment of PD FOG episodes. However, as there were no life threatening or extremely unsafe adverse reactions, further future studies would be warranted in which a larger sample size could be evaluated.