1301 - Maximizing Functional Improvement with Phenol Neurolysis for Post-Stroke Ankle Clonus: A case report in the Acute Rehab Setting

Case Diagnosis: Left ankle clonus secondary to stroke

Case Description: A 63-year-old male presented to acute inpatient rehab (IPR) after a right middle cerebral artery stroke with sustained left ankle clonus and weak left-sided dorsiflexors requiring an ankle foot orthosis for ambulation. Clonus impeded orthotic fitment and prevented ambulatory gains and was not responding to oral anti-spasticity medications. The patient underwent neurolysis with 6% phenol of tibial nerve muscular branches innervating soleus and both heads of gastrocnemius. After the injection, there was immediate elimination of clonus and the patient could wear the orthosis without issue, progressing to > 150 ft ambulation with supervision. He required no more than supervision for transfers, walking on uneven surfaces, and climbing stairs. No side effects reported. At 4-month outpatient follow up, clonus had not returned.

Discussions: Neurotoxin can be injected into the gastro-soleus complex for clonus management, but its use in IPR is limited due to cost and delayed onset of effect. Phenol is inexpensive, efficacious, and has immediate onset but requires significant technical expertise. An approach consisting of ultrasound guidance and electrical stimulation produces a well-tolerated and effective intervention. Literature is available regarding phenol neurolysis for ankle clonus, but there is little mention of its use in IPR specifically. Given that IPR is ideal for functional improvement but has limited length of stay and funding, phenol neurolysis should be considered to allow patients to attain maximal functional improvement.

Conclusions: This case suggests that the management of ankle clonus while in IPR is an opportunity to improve stroke management and functional outcomes. While phenol neurolysis requires a high level of technical expertise as compared to neurotoxin injection, phenol is cost effective and it has an immediate onset of action, which allows patients and therapy teams to maximize the benefits of the procedure while in IPR, therefore maximizing potential functional improvements.