Neuropathic pain is, by definition, pain caused by injury or dysfunction of the nerves, spinal cord or brain.

It can be caused by:

  • Compression of a nerve (e.g., carpal tunnel syndrome due to compression of the median nerve in the wrist)
  • Injury (e.g., peripheral nerve injury due to diabetes)
  • An abnormality in the processing of the pain message by the spinal cord or brain (e.g., phantom limb pain after amputation or mastectomy)

In France, neuropathic pain affects 7% of the general population.

The diagnosis of neuropathic pain is clinical, i.e., it is the patient’s description of the pain that leads to the diagnosis.

It is a particular type of pain, the patient describes “strange” sensations which can be spontaneous (burning, sensation of a vice, discharges, stabbing) and/or provoked (tingling, numbness, itching).

On clinical examination, one often finds :

  • hypoesthesia (decreased sensitivity) or anesthesia (loss of sensitivity)
  • allodynia (pain induced by normally painless stimulation)
  • hyperalgesia (excessive pain in response to a painful stimulus)

Neuropathic pain responds poorly to the painkillers usually used, including morphine.

The therapeutic arsenal will therefore be very different from that used for “classic” pain.

Medicinal treatments

The treatment of neuropathic pain is based, in the first instance, on the use of certain antidepressant and/or antiepileptic drugs which are effective in this type of pain.

These treatments are prescribed for their analgesic effects, which are independent of the anti-epileptic or antidepressant effects. They do not change your personality or your mood.

They are prescribed at the minimum effective dose. The period of action is 3–4 weeks. They may have side effects.

Antidepressants act on the molecules involved in pain control. They block the reuptake/removal of serotonin and norepinephrine, two neurotransmitters that enable us to better defend ourselves in pain.

Only certain antidepressants are recommended for the management of neuropathic pain: amitriptyline (LAROXYL), duloxetine (CYMBALTA) and venlafaxine (EFFEXOR).

Anti-epileptic drugs act by decreasing the excitability of the nerves. Two anti-epileptic drugs are recommended for the treatment of neuropathic pain: gabapentin (NEURONTIN) and pregabalin (LYRICA).

In the case of refractory pain, particularly in association with central hypersensitisation phenomena, anti NMDA drugs can be used.

NMDA receptors play a key role in the maintenance of pain.

Two anti-NMDA drugs can be used to block the receptors: ketamine and lidocaine.

These drugs are administered intravenously or subcutaneously, in hospital, in a chronic pain facility.

LUNA helps you :

LUNA’s Pillbox feature allows you to record your medication prescriptions (hormone treatments, painkillers, others…) and to schedule notifications at the time you want to take it. LUNA records this information so that you can follow the evolution of your quality of life, and your pain, linked to your treatments in real time, and also… to never forget to take your treatment again 😊

Topical treatments

When neuropathic pain is located, local treatments can be used:

Lidocaine 5% plaster (VERSATIS®)

Lidocaine is a local anesthetic available, among other things, as a plaster.

This treatment is particularly effective for allodynia.

Lidocaine works by preventing the propagation of the electrical signal along the nerves.

The patient places the patch on the painful area. He can use 1 to 3 patches, depending on the extent of the painful area, for up to 12 hours a day.

Capsaicin 8% skin patches (QUTENZA®)

Capsaicin (the active compound in chili peppers) is present in the patch in high concentration: 8%.

The patch acts by desensitizing the small epidermal nerve fibers in a reversible manner.

The patch is applied in a hospital by doctors or pain nurses trained in the technique.

The patch is applied for 30 to 60 minutes depending on the areas to be treated. A maximum of 4 patches can be applied at one time. The patch is reapplied every 2–3 months.

The capsaicin patches allow a reduction in pain equal to or greater than 30% in 42 to 70% of patients, with a reduction or even a cessation of medical treatments.

Botulinum toxin A

Botulinum toxin has two interesting properties for the treatment of pain:

Botulinum toxin is administered subcutaneously or intradermally to the painful area.

Neurostimulation techniques

Transcutaneous neurostimulation = TENS

This is a non-medicinal, non-invasive, scientifically validated pain treatment that is reimbursed by social security when prescribed by an algologist (pain doctor).

The principle of the treatment is based on the stimulation of peripheral nerve fibers using electrodes glued to the skin and connected to an external box which generates an electric current.

Repetitive transcranial magnetic stimulation = rTMS

rTMS is a recent and rapidly developing neurostimulation technique that can relieve chronic intractable pain, particularly neuropathic pain.

rTMS is a non-invasive technique that acts on the electrical activity of the brain and its functioning thanks to a coil placed in contact with the patient’s skull which induces an electromagnetic field.

It reduces the perception of the painful message.

The rTMS sessions take place in a hospital ward, by a qualified technician, under the supervision of a doctor. The effect is prolonged if the sessions are repeated, each session lasting 20 to 30 minutes.

This technique is used in several fields: pain, tinnitus, depression resistant to drug treatments, etc.

Spinal cord neurostimulation

This is an invasive neurostimulation technique which consists of implanting a stimulation electrode in the spinal cord. The electrode is connected to an external neurostimulation box.

This technique is recommended for treating chronic pain that is resistant to any treatment. The indication for the technique is subject to a multidisciplinary assessment.

The decision is taken after studying the medical file in a multidisciplinary consultation meeting.

LUNA Memo: TENS

TENS stands for Transcutaneous Electrical Nerve-Stimulation.

It is a non-medicinal, non-invasive, scientifically validated pain treatment that is reimbursed by social security when prescribed by an algologist (pain doctor).

TENS is included in the recommendations for the management of endometriosis, published by the HAS (Haute Autorité de Santé) in December 2017, as a non-drug therapeutic option.

The principle of the treatment is based on the stimulation of peripheral nerve fibres using electrodes glued to the skin and connected to an external box that generates an electric current.

Support therapies

Psychotherapies

These are recommended for motivated patients: cognitive-behavioral therapies, brief therapies, analytical therapies, etc.

Psycho-body therapies

These are always useful, although rarely sufficient.

Their aim is to teach the patient to use, in self-practice, a technique for managing stress and sleep disorders: hypnosis, relaxation, mindfulness meditation, nephrology…


Conclusion

Neuropathic pain is a particular type of pain, with an atypical symptomatology.

It responds poorly to the painkillers usually used, including morphine.

Its treatment is very specific and combines medicinal and non-medicinal treatments.

The management of neuropathic pain is the subject of guidelines in the latest recommendations for the management of endometriosis (December 2017).