830 - Chemical neurolysis in a patient with exertional compartment syndrome

Case Diagnosis: Chronic exertional compartment syndrome (CESC) is a result of increased intramuscular pressure commonly induced by exercise. Previous case series suggested botulinum A injections may be effective treatments for CESC, however the optimal dose and duration of effect varied.

Case Description: This is a female Veteran in her 30s with CESC from rhabdomyolysis. While in the military, she received onabotulinumtoxinA with the following dosage: 50units tibialis anterior (TA), 25units gastrocnemius, 25units peroneus longus, with minimal relief. Following return from the military at her first neurolysis clinic visit, she received incobotulinumtoxinA with the following dosage: 50units TA, 20units extensor digitorum longus (EDL), 20units extensor hallucis longus (EHL). At her 6-month follow-up, patient reported pain reduction from 7/10 to 2/10, with sustained effect therefore repeat injection was deferred. She also reported foot slapping for 1 month after injections. Her pain returned 9 months following the initial injections, therefore repeat incobotulinumtoxinA was performed with: 25units TA, 20units EDL, 20units EHL. She reported 40% pain relief for 4-5months and denied any adverse effects but had trouble with heel walking, therefore received repeat injections at further decreased dose of 20units TA, 10units EDL, and 20units EHL.

Discussions: Case reports of botulinum injection as treatment for CESC utilized dosages ranging 20-50units per muscle, with no clear correlation between dosage and efficacy or adverse effects. Compared to more well-studied use of botulinum for spasticity, dosage and duration of botulinum injection for CESC may depend on patient’s physical activity and demand as demonstrated in our patient who had minimal relief from higher doses of botulinum in the military but reported significant relief with similar/lower number of units after discharge.

Conclusions: When treating CESC with botulinum injections, it is important to consider each patient’s activity demand and adjust dosage accordingly.