Analysis of Adverse Effects of Cryoneurolysis for the Treatment of Spasticity

Objective: The aim of the study is to report adverse effects from clinical studies on ultrasound-guided percutaneous cryoneurolysis for spasticity.

Design: Patients were prospectively enrolled in three studies at a single institution. Cryoneurolysis was performed to primarily motor nerve branches (medial and lateral pectoral, musculocutaneous, radial, median, ulnar, tibial, obturator) and mixed motor sensory nerve trunks (median, ulnar, suprascapular, radial, and tibial).

Results: Cryoneurolysis was performed for 277 nerves (99 mixed motor sensory), on 113 patients (59 F, 54 M, average age 54.4 yrs). One patient had a local skin infection and two patients had bruising or swelling; all resolved within 1 mo. Nine reported nerve pain or dysesthesia (two motor, seven mixed motor sensory nerves). Four received no treatment, four oral or topical medications, two perineural injections, one botulinum toxin. Three patients' symptoms remained until 3 mos and one had numbness at six. One patient had botulinum toxin injections for cramping. All had at minimum 3-mo follow-up; seven withdrew (x̄ = 5.4 mos), four passed away. None of these 11 reported adverse effects.

Conclusions: A total of 96.75% of nerve treatments had no pain or dysesthesias beyond treatment. Few had pain or numbness beyond 3 mos. Cryoneurolysis has potential to be a safe spasticity treatment with manageable adverse effects.