Oral Med - Facial Pain Flashcards
what is pain?
An unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage
what can we use to aid pain assessment? (3)
- Physical symptoms
- PAIN scores/questionnaire (McGill)
- Emotional symptoms
- Psychological scores (HAD – hospital anxiety and depression scale )
- How chronic pain alters the patients perception on life
- QOL scores (OHIP – oral health impact profile)
- Assesses impact and disability of pain
- Assesses what the patient cannot do because of your pain
what is important to remember when assessing pain that doesn’t fit with anatomical boundaries?
when structures formed from each pharyngeal arch migrate they carry the nerve supply and the blood supply with them.
The supply is complex to head and neck because of the embryological origin of the tissues.
Explain how the gate control of pain works. (3)
Pain is stimulated
Rub the painful area
the Sensory fibres from Touch travels to the brain and travels to the pain ascending fibres in an inhibitory capacity – when these fibres stimulated they prevent pain signals coming from the periphery from passing information into the CNS.
Describe the changes which occur that lead to chronic pain. (4)
- Neuronal plasticity – sprouting of the spinal segment nerves
- within the spinal cord - as well as having sensory fibres which are inhibitory to the interneuron, if you have chronic pain information passing from an areas you can get sprouting of the spinal sensory nerves which can connect to the interneuron in a stimulatory way
- Therefore, any sensation makes it easier for pain signals to be passed to the brain = easier for pain to continue to pass, even when the cause removed.
- patient still continues to feel pain because of the connection between normal sensation and the pain interneurons
why is chronic pain hard to manage?
The adaptions seen in chronic pain can make it difficult for clinicians to manage/settle pain by simple/surgical means as the changes which remain within the CNS and the peripheral tissues continue to facilitate pain perception even when the stimulus has gone.
How do we manage chronic pain? (3)
- Early management of pain - using something to control peripheral sensitisation e.g local anaesthetics and NSAIDS
Use LA on the primary afferent nerve = reduce sensation which passes = allows adaptions take place. - Inhibiting the dorsal route ganglion from processing pain signals
- Applying medications, e.g. opiods, A2 agonists, tricyclics and SSRI, which change neurotransmitters in the CNS which make the adaptations less likely in the CNS = act on synapses to reduce pain perception and reduce adaptive change.
Ket and gabapentinoids useful for targeting areas within the brain itself.
What are the characteristics of chronic regional pain? (5)
- Delocalised – doesn’t fit anatomical boundaries – referred pain? Anatomical confusion between site of pain and CNS synapse?
- Describing the pain – gripping, tight, bunting – not expected pain terms
- Bilateral pain – affecting tissues in more than one area or connections happening between different nerves.
- Swelling and heat - result of autonomic reflexes
- Colour changes in overlying skin – result of autonomic reflexes
why is autonomic pain (like in chronic regional pain syndrome) more disabling than somatic nerve pain?
significantly disabling as the autonomic nerves come through the thalamus which is a more primitive part of the brain = any triggers which pass through here allow the organism to think there is a significant threat to existence = grabs the attention of the CNS = distraction is much more difficult to achieve.
How is neuropathic pain characterised? (3)
- Constant burning/aching pain
- Fixed location
- Often a fixed intensity
How does neuropathic pain present? (1)
- Usually a history of ‘injury’
- Can follow facial trauma
- Can follow extractions/normal tissue damage
- Can follow ‘routine’ treatment without complications
Briefly describe how injury cause neuropathic pain? (3)
Nerve damaged
Nerve heals in a way which causes persistent input of signal into the CNS
Neuropathic damage causes neuropathic pain
what drugs are used to manage neuropathic pain? (6 + 5)
Briefly describe how these two methods work.
- Systemic Medication
Helps reduce pain transmission in the CNS – doesn’t stop afferent info entering the CNS however reduces the effect of the signal and slows pain signalling. - Pregabalin
- Gabapentin
- Tricyclic
- Valproate
- Mirtazepine
- Opioid analgesics
- Topical Medication
Consider the gate hypothesis: using peripheral stimulation to reduce pain transmission within the CNS
Use meds to cause sensory nerve activation over the painful area = gate off the pain signals from neuropathic damage. - Capsaicin (red pepper extract: causes depolarisation of the peripheral nerve)
- EMLA
- Benzdamine
- Topical Ketamine
- Topical Lignocaine
What are the alternatives to drug management of neuropathic pain. (3)
- TENS
- Low frequency TENS
- Acupuncture – good results
- Allows opioids to reduce transmission within the CNS
- Psychological
- Distraction: attention is an important factor in pain, train people to distract themselves from their pain = less intrusive
- Correct abnormal illness behaviour
- Improve self-esteem/positive outlook
What is atypical odontalgia?
Dental pain without dental pathology
