Functional dystonia in the foot and ankle

Area of Science:

• Orthopaedics
• Neurology
• Movement Disorders

Background:

• Functional dystonia affecting the foot and ankle is a complex condition.
• Patients often experience significant pain and deformity, leading to delayed diagnosis and treatment.

Purpose of the Study:

• To characterize the clinical presentation, management strategies, and outcomes for patients with functional dystonia of the foot and ankle.
• To evaluate the effectiveness of various treatments, including Botulinum toxin (Botox) and surgery.

Main Methods:

• Retrospective review of 29 patients diagnosed with functional dystonia in a tertiary referral foot and ankle unit between 2000 and 2019.
• Analysis of patient demographics, symptom onset, diagnostic delay, treatment interventions, and follow-up outcomes.

Main Results:

• The majority of patients were female, with a mean age of onset of 35.3 years and a significant delay (7.1 years) to diagnosis.
• Most patients (26/29) presented with fixed dystonia, acute onset (25/29), and severe pain, often with coexisting chronic regional pain syndrome (CRPS).
• Treatments including Botulinum toxin (Botox) injections (1/20 good response) and surgery (0/12 improvement) showed poor efficacy, with most patients experiencing static or worsened symptoms post-treatment.

Conclusions:

• Functional dystonia of the foot and ankle typically manifests as a fixed deformity with disproportionate pain, often following minor trauma.
• Referral to neurology for exclusion of other pathologies and management in a movement disorder clinic are recommended.
• The prognosis for functional dystonia is generally poor, with limited response to current treatments and a risk of worsening with surgical intervention.