Neuroscience – the brain and pain

Neuroscience – the brain and pain

Dr Diana North, Goodfellow GP Advisor talks with Dr Gwyn Lewis, Neuroscientist about the neuroscience behind pain to enable GPs, nurses and pharmacists to understand and educate patients about pain, including:

  • Pain mechanisms that:
    • turn up the intensity of pain in the periphery and dorsal horn to protect tissue from damage.
    • turn down the intensity of pain in the periphery and dorsal horn to help us survive and to stay mobile
    • modulate pain in the central cortical systems.
  • How acute pain becomes chronic pain.  
  • Where in the pain pathway things can go wrong and result in chronic pain.          
  • The management of chronic pain.
  • Issues of overprescribing of opioids for chronic pain. 


This MedTalk was recorded in 2017




Peer group discussion points

1. Approximately 1 in 5 New Zealand adults experience chronic pain. The reasons why acute pain may become chronic pain are complex. One risk factor for the development of chronic pain is the intensity of the acute pain and how well it is managed.

  • What is your approach to the management of acute non-cancer pain?
  • If acute non-cancer pain becomes chronic pain what strategies do you introduce in terms of helping your patient manage the pain? Are there any resources you find especially useful? What is your experience with accessing additional services or resources? If access is a problem, what approach can you take with your patient?
  •  Do you think these techniques or resources are effective in the populations you see with chronic pain?

2. The use of the WHO analgesic ladder in those with cancer pain has been challenged. A newer idea is that analgesics are matched to the intensity of the pain (rather than ‘stepping up’ the pain relief intensity as required). For example, it might be appropriate for a patient with severe acute cancer pain to receive a strong opioid +/- non-opioid. The need for the use of weak opioids has also been questioned, with non-opioids or low dose strong opioids being proposed as treatment options for mild cancer pain.

  • Do you tend to prescribe weak opioids in patients with cancer pain? What do you think about the suggestion that weak opioids are avoided? Is there a place for weak opoids in primary care? Compare the NZ Formulary (‘Step-Two opioids and tramadol’) with your local guidance.
  • What opioids do you tend to use in the management of cancer pain? Are there any differences amongst the peer group? What are the reasons for these differences?
  • For those who are taking opioids to manage cancer pain, have your patients experienced tolerance to their opioid? Do you ever switch opioid type to prevent tolerance developing? What resources are available for advice regarding the safe switching of opioid medications?
  • Have you had any negative experiences with opioid prescribing (e.g. side effects, tolerance, ineffective)? How has this changed your prescribing practice (if at all)?

3. There is limited evidence for the efficacy of treatment of non-cancer chronic pain with opioids and non-opioids are likely to be as effective. There are significant risks and adverse effects associated with the use of opioids to manage chronic non-cancer pain. The treatment of chronic non-cancer pain requires a biopsychosocial multidisciplinary team approach with regards to assessment and management.

  • Has anyone undertaken an audit of opioid prescribing for non-cancer pain in their practice? What did it show? Did you make any changes to your systems or practice based on these findings?
  • Approximately half of patients seeking help with addiction were those who became addicted after being prescribed opioid analgesics. Education can be very important for our patients. Do you discuss with patients the addictive potential of opioid medications? Are they aware of the potential of diversion to the illicit market of prescription opioids? Do you check with your patients that any opioids are kept in a safe place in their homes?
  • Opioid analgesics are rarely initiated in multidisciplinary pain clinics. Access to pain clinics in New Zealand is however limited. What non-pharmacological resources are there in your community you can access to help manage chronic non-cancer pain patients (physiotherapy, acupuncture, psychologists, green prescriptions)?

This MedTalk was supported by:

Date Published: 
Tuesday, December 5, 2017
This presentation is intended for qualified health practitioners professional development and should not be relied upon for any other purpose. Any opinions offered are those of the presenter or other speaker and do not necessarily represent the views of Goodfellow Unit.