PAIN, PAIN, PAIN!!!
Pain is a primordial response. Without pain as a protective mechanism, humans may be exposed to harms and dangers that could ultimately threaten the existence of our species! However pain is distressing and if severe, can be debilitating. Pain can be physical, psychological or both in origin.
Ultimately all physical pains, as perceived by our brains, are mediated by nerves. However distinction is made between two major types of physical pains due to their differing clinical behaviours. Neuropathic pain is pain due to irritation of the nerves themselves. It is distinguished from the common type of pain (nociceptive pain) that is caused by a cut, burn or injury.
Neuropathic pain and nociceptive pain may overlap or coexist following a nerve injury.
When a person cuts his/her wrist, the tiny nerve endings at the wound are activated as a result of local tissue damage. The pain fibres then send signals to the brain that is perceived as a sharp pain (nociceptive pain). If the cut is deep enough such that the median nerve is also cut, the nerve damage will result in pain signals being transmitted via the nerve to the brain. This may be perceived as electric shock or shooting pain.
- Electric shock
Tend not to respond to simple painkillers.
May respond to antidepressant or anti-epileptic medication such as:
Tend to respond to traditional painkillers such as:
- NSAID (eg ibuprofen, diclofenac)
- Opioid (eg codeine, morphine)
What are the other symptoms of neuropathic pain?
- Allodynia: Pain due to a stimulus, which normally does not provoke pain. For instance, light stroking the skin would cause extremely unpleasant sensation.
- Hyperalgesia: An intensified reaction to a stimulus, which is normally painful. It represents increased sensitivity to pain. For instance, a light tap on a painful area would result in intense pain.
- Paraesthesia: Unpleasant sensations of tingling or pins and needles that occur spontaneously. The area of tingling gives clues to the nerve that is likely involved.
Methods of Treatment
- Therapy focusing on desensitisation and normal use of the limb.
- Pain specialist who would utilise a combination of modalities:
- Medications (often, a combination of painkillers are required).
- Peripheral nerve blockade.
- Infusion therapy of the injured limb.
- Surgery targeted at the involved nerve:
- Cut nerve > repair.
- Scarred nerve > neurolysis with or without wrapping.
- Cutaneous neuroma > burial in a muscle or bone away from the original site of injury.
- In desperate circumstances, spinal cord or deep brain stimulation is employed. This would involve neurosurgery.
- Pain is distressing. Chronic pain can be debilitating. Input from a psychologist can be very helpful in certain situations. This does not imply that the pain is due to mental health issue nor does it imply that the pain is not genuine. Instead, psychologist can help the patients develop coping mechanisms to better deal with the pain, in conjunction with other treatments.
Neuropathic pain due to an injured nerve may be amenable to surgical treatment and a multidisciplinary approach is recommended.