Botulinum Toxin in Myofascial Pain

Myofascial pain is pain arising within discreet areas of muscle. The area is known as a trigger point and can be acutely tender to touch. There is often a palpable knot or cord of muscle and pain radiates to the surrounding area, often in a recognisable pattern. There is no known cause of the condition which arises spontaneously and often disappears in the same way.

One particular type of trigger point often arises in the vicinity of surgical scars, particularly on the abdomen. This is one cause of a phenomenon known as Chronic Post Surgical Pain, which is little acknowledged by the medical profession despite being extremely common. Typically, for example, after hernial repair, up to 20% of patients still experience some degree of pain in or near their scar two years after surgery. Lack of understanding of this condition often results in sufferers being subject to numerous fruitless investigations.

Traditionally treatment of trigger points consists of massage and physiotherapy, with or without injections of local anaesthetic and steroid into the trigger point. Acupuncture can also prove effective but the benefit may be transient and repeated sessions may be necessary. Early studies have indicated that botulinum toxin compares favourably with local anaesthetic injection, particularly when comparing duration of pain relief.

Fibromyalgia is a condition characterised in part by multiple areas of pain similar to myofascial trigger points. However since the painful sites are multiple, widespread, and inconsistent in site, the condition is not amenable to Botox treatment. In addition Fibromyalgia is characterised by general malaise, a feeling of being unwell, lethargy and poor sleep. Until very recently there has been no specific treatment for this condition, but a new drug has recently been found which gives improvement in many patients with fibromyalgia.