Neuropathic pain is caused by damage or disease of the somatosensory nervous system. It is estimated to affect around 9% of the general population. Neuropathic pain has a significant burden and can reduce quality of life more than death for some patients. Conditions associated with nerve damage, such as diabetes and HIV, are increasing globally. While first-line treatments for neuropathic pain like antidepressants and anticonvulsants can provide some relief, their effects are limited. More research and access to existing treatments is still needed to help manage this challenging problem.

1. Neuropathic pain: an overview
Peter Kamerman
Seminar, Curtin University, Australia, 2017
painblogr.org @painblogR kamermanpr

2. Overview
• Types of pain
• Epidemiology of neuropathic pain
• Why worry about neuropathic pain?
• What does the future hold?
• Treatment options

3. Neuropathic pain
“Pain caused by
a lesion or
disease of the
somatosensory
system”
Jensen et al., 2011

4. Types of pain
Physiological
(nociceptive)
Clinically relevant pain
• Spontaneous pain
• Increased sensitivity
• Reduced threshold
• Increased gain

5. Types of pain
Physiological
(nociceptive)
Inflammatory
(nociceptive)
Neuropathic
Dysfunctional

6. Types of pain
Physiological
(nociceptive)
Inflammatory
(nociceptive)
Neuropathic
Dysfunctional
Pathological
Non-pathological

7. Epidemiology
of neuropathic pain

8. Epidemiology of chronic pain
Breivik et al., 2010
Prevalence of chronic pain in 46,394 adults
(Pain ≥ 5 on NRS on most days for ≥ 6 months)
26
24
22
20
18
16
14
12
30
28
% with chronic pain
Median: 18%
(bootstrap 95%CI: 16 to 23)

9. Epidemiology of chronic pain
PAIN through the ages (IF: 5.6)
1980 - 1989
2010 - 2017
1990 - 1999
2000 - 2009

10. Epidemiology of chronic pain
Breivik et al., 2010
Source of chronic pain in 4,389 with
chronic pain in Europe and Israel

11. Epidemiology of chronic pain
PAIN through the ages (IF: 5.6)
1980 - 1989
2010 - 2017
1990 - 1999
2000 - 2009

12. Prevalence of neuropathic pain in the general population
(Point prevalence with bootstrapped 95% CI)
Epidemiology of neuropathic pain
Median: 9%

13. Imperfect tools provide imperfect measurements
Epidemiology of neuropathic pain

14. Imperfect tools provide imperfect measurements
(Model based on the DN4-interview -- sensitivity: 82%, specificity: 86%, n = 3000)
Epidemiology of neuropathic pain
epiR 0.9.76: Stevenson et al., 2016

15. Imperfect tools provide imperfect measurements
Epidemiology of neuropathic pain
DN4-interview
Sensitivity = 82%
Specificity = 86%
S-LANSS
Sensitivity = 75%
Specificity = 80%
(Point prevalence with bootstrapped 95% CI)

16. Imperfect tools provide imperfect measurements
Epidemiology of neuropathic pain
DN4-interview
Sensitivity = 82%
Specificity = 86%
S-LANSS
Sensitivity = 75%
Specificity = 80%
(Point prevalence with bootstrapped 95% CI)

17. Why worry about
neuropathic pain?

18. Prevalence of pain in people with a ‘neuropathy’
Haanpaa et al., 2009; Sadosky et al., 2008; van Hecke et al., 2014; Veves et al., 2007
Epidemiology of neuropathic pain

19. Burden of neuropathic pain
Torrance et al., 2013
"17% of people with neuropathic
pain rated their quality of life as
being worse than death."

20. Burden of neuropathic pain
Meyer-Rosberg et al., 2001
Impact of neuropathic pain on health

21. Burden of neuropathic pain
Lalli et al., 2013; Geelan et al., 2017
Impact of neuropathic pain on health
Attribute Diabetes
(%, n = 20)
Diabetes +
Neuropathy
(%, n = 20)
Diabetes +
Neuropathic pain
(%, n = 20)
Fell in the last year 15 20 45
Fear of falling 5 20 64

22. Burden of neuropathic pain
Schaefer et al., 2014
Impact of neuropathic pain on work

23. Burden of neuropathic pain
Smith et al., 2007
Impact of neuropathic pain vs other chronic pain

24. What does the
future hold?

25. Conditions associated with nerve damage
The future
Global Health Data Exchange: GHDx 2016
Year
Developing Developed

26. Burden of neuropathic pain
HIV neuropathy
HIV: Ellis et al., 2010;
painblogr.org/2016-02-22-hiv-neuropathy-down-but-not-out.html
The future
Post-herpetic neuralgia
PHN: Oxman et al., 2008

27. Burden of neuropathic pain
Painful diabetic polyneuropathy
Guariguata et al., 2014; NCD-RisC, 2016; Veves et al., 2007
The future

28. Treatment options

29. Burden of neuropathic pain
First-line treatments
Finnerup et al., 2015
Treatment
Second-line treatments
(duloxetine and venlafaxine)

30. (duloxetine and venlafaxine)
Burden of neuropathic pain
First-line treatments…not the strongest effects
Finnerup et al., 2015
Treatment

31. Burden of neuropathic pain
First-line treatments…not the strongest effects
Finnerup et al., 2015
Treatment

32. Burden of neuropathic pain
Finnerup et al., 2015
Treatment
Second-line treatments…not the strongest effects

33. Availability of treatments
Kamerman et al., 2015; Interactive map: painblogr.org/2017-02-11-eml-drug-map.html
†: TCA = tricyclic antidepressants; α2δ-ligand = gabapentin and pregabalin;
SNRI = serotonin and noradrenaline reuptake inhibitors (duloxetine and venlafaxine)
1st-line

34. Availability of treatments
Kamerman et al., 2015; Interactive map: painblogr.org/2017-02-11-eml-drug-map.html
‡: weak opioid = tramadol;
topical agents = 5% lidocaine patch and 8% capsaicin patch
2st-line

35. Availability of treatments
Kamerman et al., 2015; Interactive map: painblogr.org/2017-02-11-eml-drug-map.html
§: strong opioids = morphine and oxycodone;
other = botulinium toxin A
3st-line

36. Availability of treatments
WHO, 2008
WHO Model Formulary
Recommendations for neuropathic pain

37. Conclusion
• Epidemiology of neuropathic pain
• Why worry about neuropathic pain?
• What does the future hold?
• Treatment options