2.09 Chronic Pain management

Question 1

What is pain?

Answer 1

unpleasant sensory and emotional experience

associated actual tissue damage or described in terms of such damage

Question 2

What are the 2 main neurotransmitters involved in pain neurotransmission at the spinal cord?

Answer 2

Substance P

Glutamate

Question 3

How is the affective part of the brain alerted to pain?

Answer 3

Lamina I projects to the parabrachial, which projects to the amygdala, which alerts the brain.

Question 4

How is the sensory part of the brain alerted to pain?

Answer 4

A delta and C fibres synapse onto spinal cord, and Lamina V projects to the thalamus, and the somatosensory cortex.

Question 5

What is nociceptive pain?

Answer 5

pain from injury relayed through a normal nervous system.

Question 6

What is neuropathic pain?

Answer 6

Pain generated within nervous system.

Question 7

What kind of pain is this?

• burning, shooting, tingling, sensitivity
• sensory changes
• allodynia- painful to cotton wool
• hyperalgesia- pin prick= ++++pain

Answer 7

Neuropathic pain

Question 8

What are the most common causes of neuropathic pain?

Answer 8

shingles- post herpetic neuralgia
diabetic neuropathy
amputation
surgery
trauma

Question 9

What are some medical options for managing neuropathic pain?

Answer 9

1. Tricyclic antidepressants- amitriptyline
2. anticonvulsants- gabapentin, carbamazepine
   opioids- morphine
   NMDA antagonist- ketamine
   Na+ channel blockers- lignocaine
   Capsaicin
   GABA agonists - Baclofen
   Duloxetine
   Lidocaine patch
   cannabinoids

Question 10

What are the possible complications for pain in cancer survivors?

Answer 10

post surgical pain
chemotherapy induced painful peripheral neuropathies
chronic graft vs host disease
radiation induced pain syndrome 
hormonal therapy and arthalgias

Question 11

What is the peripheral sensitization mechanism for pain after injury?

Answer 11

A reduction in the threshold of peripheral afferent nociceptors

Question 12

What is the central sensitization mechanism of pain after injury?

Answer 12

Increased excitability of spinal neurons
rewiring of spinal cord
changes in the brain

Question 13

What are the non-medical management options for pain?

Answer 13

TENS machine
accupuncture
physiotherapy
occupational therapy
psychology
pain management programmes

Question 14

What are the intermediate-long term medical management options for pain?

Answer 14

Nerve blocks 
Intrathecal drug delivery systems
spinal cord 
epidural steroids 
facet injections leading to denervation 
stellate ganglion block 
trigger point injections

Question 15

Is phantom limb pain more prevalent in immediate or delayed amputees?

Answer 15

Delayed amputees (>70%) 
compare to immediate amputee (40%)

Question 16

What occurs in the brain when there is amputation/loss of a body part? (to the sensory cortex, etc.)

Answer 16

There is sensory remapping.

Question 17

What are general guidelines in opiate prescription for non-malignant pain?

Answer 17

Opiates are effective for pain but they may impact function.
Risk of: death.
Useful in nociceptive and neuropathic pain
Remember to have goals and reviews; consider rehabilitation contracts?

Question 18

What are the side effects of long term opiate use?

Answer 18

Hormonal- adrenal, libido
immunomodulation
hyperalgesia
osteoporosis

importance of these are unknown