Neuropathic or nerve pain arises as a result of damage or improper functioning of the nerves/nervous system. It presents as poorly localized burning, shooting or electric shock-like pain with altered sensitivity in the affected area. The sudden increase in pain severity is commonly observed. Over the period of time sometimes skin changes, weakness, and wasting of muscles can develop. The affected area may develop increased sensitivity perceiving nonpainful stimuli such as touch to be painful. Alternatively, patient may report having pain in areas which feel numb. Some examples of common conditions with neuropathic pain include
- Diabetic Neuropathy where patients complain of a burning sensation most commonly in the sole of feet, worst at night time
- Infections such as Post heretic neuralgia, HIV
- Persistent post-surgery pain or trauma involving nerve damage
- Drug-induced neuropathy including that after chemotherapy/radiotherapy
- Cancer-related neuropathy
- Post Amputation- Phantom limb pain
- Central causes such as spinal cord injuries, strokes, multiple sclerosis
- Complex Regional Pain Syndrome
- Nutritional deficiencies
Screening questionnaires are commonly used in diagnosing neuropathic pain. Investigations such as blood tests, scans, and nerve and muscle tests may be requested to confirm the diagnosis or rule out other conditions. Depending on the history, examination and investigation findings the pain condition is diagnosed as possible, probable or definite neuropathic pain.
Neuropathic pain can be severe with significant impact on the quality of life. Sleep disturbances, anxiety and depression are frequently observed along with pain. Multi-disciplinary approach has the advantage of addressing all concomitant factors involved in exacerbating pain and affecting quality of life. Some of the common interventions include
Drugs labelled as Neuropathic agents are specifically used to treat pain neuropathic pain. Whilst they may have been made to treat other conditions (like epilepsy and depression) it is not uncommon for drugs to be used for multiple conditions. A number of anticonvulsants and antidepressants are well reorganised pain killers for nerve pain. Examples of these drugs include Gabapentin, Pregabalin, Nortiptyline etc. Please follow the link to medication optimisation to find out more.
Nerves carry the pain sensation to the brain and blocking this transmission can be achieved by nerve blocks. These are useful when the pain generator are the nerves themselves and in conditions where the focus is on reducing pain, improving quality of life. An example of this is persisting knee pain after joint replacement surgery despite there being no problem with the replaced joint. In such cases Genicular nerves which carry pain sensation from the knee are targeted to reduce pain. It is important to understand that persisting pain does not always signify ongoing damage. The nerves targeted will depend on the area involved and may includesympathetic nerves as in Sympathetic blocks e.g. stellate ganglion block, Hypogastric plexus block.
Transmission of pain impulses to brain can also be reduced by other interventions such as radiofrequency treatment and Neurolytic blocks. Further details of this are mentioned in other sections of this website depending on the body part involved such as for shoulder pain further information about suprascapular nerve can be found in the joint pain section.
Some drugs when given through the veins over a period of time can produce prolonged pain relief when the source of pain is the nerves/nervous system. These drugs can help to reduce the sensitivity of nerves at the site of lesion and in spinal cord which in turn leads to reduced pain sensation being transmitted to brain.
As nerve injury /dysfunction may be accompanied by weakness/ atrophy of muscles, physiotherapy forms an essential pillar of overall management. It helps in preventing deconditioning of muscles and preserving the functionality. Please follow the link for finding out more about how physiotherapy can help.
Options including cognitive behavioral therapy, coping strategies and relaxation techniques can help in dealing with flare up episodes and any accompanying mood disturbances. Please follow the link for finding out more about how psychology can help.
Dr. Amod Manocha is a Senior Consultant and Head of Pain Management Services at Max Multispecialty Hospital, Saket. He is trained as a Pain Management Specialist and an Anaesthetist in the UK. He has over 13 years of work experience in the UK including working as a Chronic Pain Consultant in many UK hospitals.