Pain is a sensory and emotional experience which can cause serious psychological changes in the person. Pain develops early in 90% of brachial plexus injury cases, and it may be also delayed for 3-4 months. Generally the pain improves by 2-3 years and is usually manageable by the patients. But in 30-40% of patients the pain becomes very severe and unbearable. Pain after injury can be divided into paroxysmal (shock like) pain and continuous (burning) pain. The continuous pain is a chronic burning or stabbing pain that does not ordinarily follow a clear distribution and usually located in the forearm and the hand. The other paroxysmal pain is a sharp electric shock like pain which is crushing, very severe, lasts few minutes and can occur every few minutes and sometimes ‘like putting your hand in a deep frying pan’. Some of the characters of the pain described by the patients are as follows, “ my arm is on fire with continuous electric shocks 24 hours, even a small noise like tapping aggravates pain, I wanted to end my life and attempted suicide several times, I used to have 24hrs pain very slightly reduced with tablets, pain will start from hand all the way up to neck, pain was like pin pricks or someone was stabbing my arm and every time it was different, 22yrs I had pain and even the slightest noise like a baby crying will set it off, I chewed my hand daily for pain relief as it was like on “burning oil”.
Surgery may be possible to repair damaged nerves. In order to have a chance of success this surgery must be performed within a few months of the injury.
1.Nociceptive pain – This follows an injury to skin, muscles, bones or tendons. It usually settles with healing but can persist and can recur over time.
2. Neuropathic / nerve pain – This is due to damage to the nerves. You may feel some pain that can be different from anything you have felt before. It may vary from mild pins and needles to more severe nerve burning pain or electric shock like shooting pain. Neuropathic pain can be difficult to treat and may respond better to special medicines, which have different actions from normal painkillers. BPI is the worst for of neuropathic pain, which can be very challenging to treat.
The specialist can assess the pain by asking the following questions, as the treatment will vary according to the type of pain.
1. Location of pain: Is it in a single place or multiple locations on the body? The location and pattern of distribution of the pain can lend clues as to the cause.
2. Nature of pain: Is the pain intermittent, does it come and go depending on something you do like a movement or activity or is it constant and unrelieved?
3. Duration of pain: Is it related to an injury in the acute phase and associated with a normal painful response? Is it chronic – lasting for some months due to an ongoing condition?
4. Intensity of the pain: Often measured on a scale of 1-10 (with 10 being the worst pain).
5. Quality of pain: Is it sharp, does it burn, is it throbbing, does it feel like an electric shock etc?
6. Other factors: Do you have any other symptoms e.g. depression, sleep disturbances, changes in appetite, etc?
The treatment methods for pain relief are surgical methods or non-surgical methods. We will discuss about both methods in detail below.
Some of the medications used to treat pain are:
Non steroidal anti inflammatory (NSAID’s) – These drugs include Diclofenac, Ibuprofen and others. They work by reducing hormones that cau se inflammation and pain in the body and are used to reduce pain, inflammation and stiffness caused by many conditions. Paracetamol can be used with these combinations.
Tramadol – This is effective in the management of moderately severe acute or chronic nociceptive pain. It is often useful when administered with other drugs.
Anti epileptics e.g. gabapentin, pregablain, carbamazepine, lamotrigine, Gabapentin (Neurontin) – This is used to help relieve certain types of nerve pain, but has another use as it can also be prescribed for patients who need help to control seizures (convulsions) or epilepsy. This is usually started at a low dose and gradually increased until a benefit is seen. This drug should not be stopped abruptly. Lyrica (Pregabalin) or Gabapentin are the commonly used drugs.
Anti depressants e.g. amitryptyline, duloxetine – Amitriptyline is in a class of drugs called tricyclic antidepressants. It may be used to treat nerve pain but has another use in patients with symptoms of depression such as feelings of sadness, worthlessness, or guilt; loss of interest in daily activities; changes in appetite; tiredness; sleeping too much or insomnia. It is often given at night and can improve sleeping patterns but may take up to 2 weeks to notice any pain relief.
Topical medicines – E.g. gels, creams, patches
TENS (Transcutaneous Electrical Nerve Stimulation) – This is a small portable electrical device which is designed to help relieve pain. It works by sending a harmless electrical current through pads that are placed on your skin. This is felt as pins and needles and these feelings can help to block pain messages.
Medical management can fail after sometime when either a single drug or combinations of drugs have been taken up to the maximum acceptable dose for a duration of few months to years or when side effects do not allow you to take the medication that is required. When such a situation arises it is wise to consider surgical options.
Surgery should be considered only when medical and other treatment methods have failed over a period of 6 months to 2 years and the patient can no longer accept the pain.
The surgical options available are:
• Nerve block surgeries
• Intrathecal pumps delivering painkillers direct to the area affected
• Ablative (destructive) surgeries, which involve the burning of nerve endings.
In BPI the nerve can be pulled our or disconnected from the spinal cord. The region where it gets disconnected undergoes scare tissue and become a focus of pain generation. This region is called the “Dorsal Root Entry Zone” (DREZ), which is the first important level of modulation for pain and hence this area can be a target to treat resistant neuropathic pain in avulsion injuries.
The dorsal root entry zone (DREZ) lesioning procedure is a treatment for severe pain caused by nerves that have been torn away (avulsed) from the spinal cord. The procedure itself involves a neurosurgeon entering the spinal cord and causing multiome lesions that damaged areas of pain generation from the spinal cord. Operation performed by Dr G.Balamurali. Senior Consultant Spine and Neurosurgeon MBBS, MRCS, MD(UK), FRCS (NEURO)
The success of surgery can be classified as
“Excellent” – when complete improvement was achieved,
“Good” when relief was 50% or more,
“Mild” when improvement was less than 50%
“Poor” when there was no pain relief or in cases of pain exacerbation.