Morton’s neuroma is a chronic and progressive nerve entrapment syndrome that affects a fair percentage of the general population and causes neuropathic pain and discomfort along the second or third metatarsal space.
A 2013 study(1) reported that botulinum toxin A had been used successfully for the management of several conditions that are associated with neuropathic pain or loss of muscle tone. The study also suggested that the mechanism of action of botulinum toxin A makes it an ideal option for the management of neuropathic pain in Morton’s neuroma.
Botulinum Toxin A (Botox) is made up of a simple peptide unit that constitutes one heavy and one light chain, attached via disulphide bridge(1). The mode of action of Botox injection is specific for blocking the release of acetylcholine at the motor endplate with its protease like action to result in:
A 2013 study by José M. Climent and associates(2) assessed the effectiveness of Botox for the management of Morton’s neuroma in 17 patients who had pain and discomfort which lasted for more than 3 months and had not responded to conventional therapies. After administration of Botox in the neuroma, investigators assessed the pain and mobility over the next three months and concluded that:
The therapeutic effects of Botox therapy are largely dose-dependent and usually a small dose of just 50U is considered effective for optimal alleviation of symptoms. The effects of Botox therapy are usually evident within 2-3 days (48 to 72 hours) after the administration of injection. Typically, the peak clinical efficacy was achieved over the next 1-3 weeks. Based on several clinical studies, the effects can last up to 3 months, possibly longer(1,2).
Although, currently Botox therapy is not considered the first-line of treatment for the management of Morton’s neuroma, it at least as effective and viable as corticosteroid injections in terms of therapeutic benefits (with minimal risk of adverse effects)(3) and it is comparable in effectiveness to alcohol injections(4). It is important to note that the quality of results of Botox may vary depending upon the technique, intensity of initial symptoms and related factors.
We do not routinely use or recommend Botox to treat Morton’s neuroma for the following reasons: