Botulinum Toxin Treatment for Nocturnal Calf Cramps in Patients With Lumbar Spinal Stenosis: A Randomized Clinical Trial.

OBJECTIVES

To evaluate the clinical effectiveness of botulinum toxin (BTX) injection into the gastrocnemius muscles in patients with lumbar spinal stenosis (LSS) who have frequent nocturnal calf cramps (NCCs).

DESIGN

Prospective, randomized clinical trial.

SETTING

Outpatient department for interventional pain management.

PARTICIPANTS

Patients (N=50) with LSS who have NCCs at least once per week were enrolled.

INTERVENTION: Patients were randomly allocated to receive either conservative treatments plus gabapentin (group GPN) or BTX injection (group BTX).

MAIN OUTCOME MEASURES: We assessed back/leg pain intensity, the frequency and severity of NCCs, insomnia severity, and functional disability at baseline and after 2 weeks, 1 month, and 3 months. Additionally, Patient Global Impression of Change was assessed.

RESULTS

Forty-five patients completed all assessments (group GPN, n=21; group BTX, n=24). Compared with group GPN, leg pain intensity, cramp frequency, and cramp severity were significantly decreased in group BTX at all follow-up visits (all, P<.01). Also, insomnia significantly improved in group BTX at the 2-week (P=.018) and 1-month follow-up (P=.037). Functional disability significantly improved in group BTX at 2 weeks' follow-up (P=.041). At the 3-month follow-up, patients in group BTX reported a higher impression of improvement for NCC symptoms than did those in group GPN (P<.001). A mean dose of 642.8mg of gabapentin was given daily in group GPN, but 7 patients (33.3%) reported systemic side effects. There were no serious complications related to BTX use.

CONCLUSIONS

BTX treatment appears to be effective and safe for NCCs in symptomatic LSS patients receiving conservative care.