To report the treatment benefits of botulinum toxin A (Botox) in the treatment of refractory neuropathic pain in both diabetic and idiopathic neuropathy.

Neuropathic pain is a frequent complaint in patients with peripheral neuropathy secondary to diabetes or other causes. It can have a significant impact on quality of life and lead to difficulty with activities of daily living. Many symptomatic treatments have been studied and proven effective, but a significant number of patients still experience uncontrolled pain or intolerable side effects. A small cross-over trial has suggested efficacy of Botox after one round of injections, but multiple sessions have not been examined and there has not been a large clinical trial.  

Patients were selected based on having a known diagnosis of neuropathy and having failed an adequate trial of 3 standard neuropathic pain medications. They were treated with intradermal injection of Botox at 10 sites on the dorsum of each foot every 3 months. Total of 100U were used for each procedure. The 11-point Likert numeric scale was used to assess their pain before during and after treatment. 

8 male veterans were identified and consented to a trial of Botox for neuropathic pain. Ages ranged from 47 to 90 years. 1 patient had idiopathic neuropathy while the remainder had diabetes. Average duration of neuropathic pain was 9 years. The treatment duration with Botox ranged from 3 months to 12 years. One patient withdrew after first injection due to inconvenience and less improvement than expected. All other patients reported significant improvement with average reduction of 6.2 points on the Likert scale. The treatment benefits sustained in all responders.

In this case series, intradermal injection of Botox every 3 months offers effective and sustained reduction in neuropathic pain in both diabetic and idiopathic neuropathy and is well tolerated.