Nerve pain

What is neuropathic pain?

It is essentially nerve pain. It may be because it is primarily affected or because it is close to other affected tissue. It is usually a poorly localised pain, rare, difficult to describe (cold, hot, tearing, tense, pins and needles, electric shocks, oppressive, tense) and may persist even after the apparent cause has disappeared (e.g. pain from a scar after breast, lung or inguinal hernia surgery).

Why is it important to know what neuropathic pain is?

Because of its characteristics, it often persists in the absence of objective injuries and may not be sufficiently taken into account or understood by family members, friends, colleagues, or even other doctors.

Why does herpes hurt so much?

Precisely because one or more nerves become inflamed, usually in the ribs but it can occur in any nerve in the body (eye, face, leg, arm). It is very important to relieve the pain as soon as possible to prevent our brain from ‘memorising’ the pain too much. Therefore, if you have not achieved good pain control with the medication you have been given, it is advisable to see a pain specialist to receive the most appropriate information and treatment and thus prevent the pain from becoming chronic. Even so, unfortunately it is sometimes difficult to prevent the onset of postherpetic neuralgia, which consists of persistent pain long after the herpes blisters have healed. This type of neuralgia is more common in elderly people and those who are immunocompromised (people with low defences).

I am diabetic and I feel a burning pain in my legs. What should I do?

Diabetes is another cause of nerve inflammation. There are various ways in which the nerves can be affected by this disease. The most common symptom is a burning pain and numbness in the farthest part of the legs, like a sock. Fortunately, good diabetes control prevents its onset and, if it does occur, delays or prevents its worsening.

Why am I being given antidepressants to treat pain?

There is extensive experience with the use of low-dose antidepressants (without antidepressant effect) in the treatment of neuropathic pain. They are particularly useful in controlling oppressive, tense, continuous pain.

At low doses, they have few side effects, the most common being drowsiness and dry mouth. The most commonly used is amitriptyline.

Why am I being given antiepileptic drugs to treat pain?

They are another family of drugs that have proven useful in the treatment of neuropathic pain. Tegretol (carbamazepine) has been used for many years to treat trigeminal neuralgia. There is now a new generation of anti-epileptic drugs with fewer side effects that are equally effective. They are particularly useful for controlling pain in the form of intense, intermittent bursts.

What is a lidocaine infusion?

It is a drug with various applications, such as local anaesthesia and the treatment of ventricular cardiac arrhythmias. Precisely because of its effect in reducing nervous excitability, it is used for the treatment of neuropathic pain via the bloodstream.

Reflex sympathetic dystrophy

I broke my hand three weeks ago and my whole arm has become swollen and painful, with changes in temperature and colour. What is happening to me?

There is evidence that direct injury to a nerve or its vicinity can trigger a neurovascular disorder, in other words, one involving both nerves and arteries and veins, and in which changes in the volume of the affected limb (hand, arm, foot, leg), changes in colour and temperature, pain and progressive immobility are observed. Sometimes the trigger is a minor trauma. It is highly advisable to recognise or suspect this syndrome in order to relieve the pain as soon as possible and begin pain-free rehabilitation sessions to prevent stiffness and, ultimately, loss of limb function.