Clinical Lecture: Pain Management

Question 1

Describe some of the parts of the Brian that are involved in the perception of brain?

Answer 1

• Insula - The imagination of pain
• Amygdala - The emotional component of pain
• Prefrontal correct - modulates the experience of pain. It can even allow the dampening fo pain slightly.
• Anterior cingulate- attention of pain
• Hippocampus - Memory of pain
• Somatosensory cortex - location and amplification of pain
• Brainstem - Viscerla component of pain e.g. increased heart rate, increased BP or nausea

Question 2

What is the Nocebo effect?

Answer 2

This is the delivery negative information in the treatment leads to the patient perceiving a poorer outcome. This can be the development of adverse side effects or worsening in the condition.

Question 3

How can we manipulate the features of gate theory of pain to treat pain?

Answer 3

We can use massage, TENS machine or spinal cord stimulation. This is as A-beta fibres carrying mechanoreceptors can cause stimulation of inhibitory neurones. This inhibits pain travelling in C fibres. This helps to dampen down pain.

Question 4

What is the role of descending inhibitor fibres?

Answer 4

Descending inhibitory fibres do not travel in tracts per say. The pain is modulated at the brain level. Also at the midbrain - at the periaqueductal grey matter. This area is rich in opioids.

Descendingcorticospinalfibresproduce postsynapticinhibitionof nociceptive spinal neurons will not affect pain sensation.Inhibitory control from the periaqueductal grey-rostral ventromedial medulla (PAG-RVM) system preferentially suppresses nociceptive inputs mediated by C-fibres, preserving sensory-discriminative information conveyed by more rapidly conducting A-fibres.

The pain neurotransmitters in this pathway are serotonin and noradrenaline.

Question 5

What are the differences between nociceptive and neuropathic pain?

Answer 5

Nociceptive pain:

• Pain due to tissue damage and inflammation
• This is an aching pain after a minor injury, limb injury etc.
• treated with rest, exercise to allow rapid
• It usually resounds to pain medication such as paracetamol, NSAIDs, weak opioids etc.

Neuropathic pain:

• This is pain imitated or caused by primary lesion or dysfunction in the CNS or PNS
• An example include diabetic neuropathy, trigeminal neuralgia, phantom pain or shingles
• Treated using neuropathic medication such as Gabapentrin, Pregablin, Amitryptyline etc. These drugs to have adverse effects and tend to have a lower success rate
• Also can use spinal cord stimulation

Question 6

Give examples of positive and negative signs of neuropathic pain.

Answer 6

Postive signs: Pins and needles, tingling, hyperalgesia

Negative signs: Numbness, clumsiness and loss of coordiantion

Question 7

Why do not all pain medications work?

Answer 7

• Untreated biopsychosocial factors such and depression, trauma, legal issues
• Tolerance - this occurs particularly with opines
• Misdiagnosis
• The drug is not tolerated
• The drug is not effective long term in chronic pain