Neuropathic pain is pain due to nerve damage or disease. However, people commonly present with “features of neuropathic pain” with no nerve injury. This is seen commonly in shoulder pain which can have intermittent pins and needles to the hand. This is probably nerve dysfunction or irritation in those nerves supplying the hand. “Neuropathic pain” includes sensations such as burning, pins and needles, numbness, electric shocks, itching, crawling (formication) and pain on light touch (allodynia), painful cold and squeezing. The sensation also come on randomly with rhyme or reason.  Neuropathic pain is also commonly associated with the pain being much worse than expected (hyperalgesia), and it can create a large degree of emotional distress. 

This type of pain is treated with medications and neurostimulation. The most common medications used are amitriptyline (Endep), pregabalin (Lyrica) and duloxetine (Cymbalta, Andepra). There are a range of other medication, but these are all less effective than these four. Amitriptyline and duloxetine are anti-depressants and pregabalin an anti-epileptic. They can be thought of as nerve stabilisers and they reinstate the normal mechanisms that inhibit pain. They have list of side effects as long as your arm, but the primary issues with all of these is drowsiness. This can be dealt with by starting with a low dose and gradually building up. They are metabolised differently, so if side effects are a problem, swapping between them may be useful. They can also be used a creams. This decreases the amount of absorption into your system and can decrease side effects. If you don’t tolerate any of them, we can consider other medications, or just stop them and move onto the next option. If you are on one of these medications already it should be trialled for 4-6 weeks. If during that time you don’t tolerate the side effects or it is not effective, it should be stopped.  

Neurostimulation is the use of electrical pulses to alter nerve function and decrease pain. It involves the insertion of leads either under the skin, or within the spinal column. The lead is then connected to a battery which sits under the skin and delivers the impulses. 

There are a number of options for neurostimulation. Percutaneous electrical nerve stimulation (PENS) is where stimulation is delivered for 60 minutes and no leads are left in place. It can effectively decrease pain for 6 -12 months.   Peripheral nerve stimulation is similar to PENS but it is a permanent implant where leads are placed under the skin to stimulate peripheral nerves. This can be effective in the treatment of headache, chest wall pain and focal buttock pain. Leads can also be placed in the spinal canal to directly stimulate pain fibres in the spinal cord. This is referred to as spinal cord stimulation and is used for people suffering lower back and leg pain.  The last version is dorsal root ganglion stimulation. This type of stimulation targets the nerves as they enter the spinal canal and is particularly good for focal nerve pain.

Presentation: A Comprehensive Algorithm for Management of Neuropathic Pain

Dan Bates, Michael Hanes, Neil Jolly, Carsten Schultheis, Krishnan Chakravarthy, Tim Deer, Rob Levy, Corey Hunter