Post-herpetic neuralgia is a painful condition that persists after a shingles episode is over. The sharp and shooting pain associated with post-herpetic neuralgia occurs in the same area as that of the pain and rash of shingles and results from the damage to nerve fibres during the shingles infection.
Post-herpetic neuralgia is not generally considered life threatening, though the condition can lead to insomnia, weight loss, depression and even disability in some cases. Patients may also become hypersensitive to even a very light touch or pressure on the skin, such as when touched by hand, a piece of cloth or even a gentle breeze.
Botox (Botulinum Toxin A)
Patients that have easily identifiable trigger points, permanently contracted muscles, or headaches that are associated with muscle spasms are very good candidates for Botulinum Toxin A injections. Botox is the industry name for Botulinum toxin type A, which is derived from a strain of bacteria called Clostridium Botulinum. When Botox is injected into a muscle, it blocks the signals sent from the brain which tell the muscle to contract. Botox targets the muscles involved by effectively disarming them and ensuring that they do not send panic signals throughout the body. The body believes that there is no pain being experienced. Botox can help to keep the muscle relaxed for anywhere from three to six months, after which it is hoped that the muscle will be able to contract normally without pain or spasms.
Botox injections are performed as an outpatient procedure at the London Pain Clinic, with patients free to leave as soon as the treatment has been administered. Initially, the treating doctor will spend time identifying the individual trigger points, sometimes with the help of a physiotherapist, and will mark the areas with a pen. The located areas will then be sterilised with a chlorhexidine antiseptic spray and a fast acting local anaesthetic will be will injected through a small cosmetic needle.
The Botox can then be administered by one of three different ways, depending on the case. Small cosmetic needles are usually preferred, but a Stimuplex nerve stimulator or ultrasound guidance are sometimes necessary if the trigger points are more difficult to access. 100 units of Botox are usually administered, but this can increase up to 200 units depending on the affected area.
One of the major advantages of Botox is that there is little or no recovery time, and most people feel fine and can return to their normal life immediately. The results of treatment should last around 3-6 months and the procedure can be repeated after this time.