Head and neck muscle spasm after radiotherapy: management with botulinum toxin A injection.

OBJECTIVE To introduce the concept of neck muscle pain and spasm after radiotherapy and its treatment with botulinum toxin A. DESIGN Case series. SETTING Ambulatory patients at a tertiary care medical center. PATIENTS Individuals who had undergone primary or adjuvant radiotherapy for treatment of carcinoma of the head and neck were asked about painful spasms of the neck musculature. A volunteer sample was used. If they desired treatment with botulinum toxin A, they were included in the study. INTERVENTION Patients received botulinum toxin A injections to the affected sternocleidomastoid muscle(s) in 1 or 2 locations. OUTCOME MEASURE Subjective pain relief. RESULTS Four of 6 patients with painful tightness of the neck who received botulinum toxin A injections to the sternocleidomastoid muscle achieved pain relief. CONCLUSIONS A subset of patients with irradiation-induced cervical muscle spasm benefit from treatment with botulinum toxin A injections. Further study is needed to more clearly define the entity and treatment.