Ch28 Pain Flashcards
What are the types of pain?
- Nociceptive
a) somatic: well-localised.
b) visceral: poorly localised. - Deafferentation pain: poorly localised. Described as crushing, tearing, tingling or numbness. Also causes burning dysesthesia numbness often with lancinating pain and hyperpathia. Unaffected by ablative procedures.
- CRPS
- Neuropathic (not in Greenberg)
Give three causes of peripheral neuropathic pain
Any of: Focal: Entrapment neuropathies Radiculopathy Neoplastic nerve compression or infiltration Postherpetic neuralgia (PHN) Trigeminal neuralgia Post-traumatic Neuralgias
Regional
Complex regional pain syndrome (CRPS)
Phantom limb pain
Postradiation plexopathy
Systemic Acute and chronic inflammatory demyelinating polyradiculopathy (CIDP) Alcoholic polyneuropathy Chemotherapy-induced polyneuropathy HIV sensory neuropathy Toxic exposure-related neuropathies Nutritional-deficiency neuropathies Painful diabetic neuropathy (PDN)
Give three cases of central neuropathic pain
Any of: Spinal Cervical spondylitic myelopathy HIV myelopathy Posttraumatic spinal cord injury pai Postischaemic myelopathy Postradiation myelopathy Syringomyelia
Cranial
MS related pain
PD related pain
Poststroke pain
Give three medical treatments for neuropathic pain? (apart from simple analgesics)
Tricyclic antidepressants
Gabapentin
Lidocaine
Give three cephalic neuralgias
Any of
CN
Trigeminal neuralgia
Trigeminal neuropathic pain aka trigeminal deafferentiation pain (injuries, surgery, ablation)
Geniculate neuralgia (otalgia and deep prosopalgia (facial pain)
Tic convulsif (geniculate neuralgia with hemifacial spasm)
Glossopharyngeal neuralgia
Branches of CNs
Superior laryngeal neuralgia
Sphenopalatine neuralgia
Supraorbital neuralgia
Non cranial nerves
Occipital neuralgia
Infections
Herpes Zoster
Postherpetic neuralgia
Ramsay-Hunt syndrome
Neurology
Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT)
What test can you use to investigate whether otalgia is secondary to glossopharyngeal neuralgia
cocainization or nerve block of pharyngeal tonsils
What are the most common trigger mechanisms in primary otalgia?
Primary otalgia is unilateral in most
Trigger mechanisms are identified in slightly more than half with cold air or water being the most common
75% have associated aural symptoms - hearing loss, tinnitus, vertigo
What is treatment strategy for primary otalgia
- Medical (same meds as TN)
- If intractable and no response to pharyngeal anaesthesia then can explore 7th (nerve intermedius), and lower cranial nerves. If MVD fails or no significant vessels are found, Rupa et al recommend sectioning the nervus intermedius, the 9th and upper 2 fibres of CN X and a geniculate ganglionectomy (or if glossopharyngeal neuralgia is strongly suspected just 9th and upper 2 fibres of 10)
Describe typical features/demographics of supraorbital neuralgia
Rare. Slightly more common in women. Typically 40-50 years.
Pain is chronic-continuous or remitting-intermittent.
1. Primary. No known aetiology and no sensory loss.
2. Secondary. More common than primary SON. Most cases remit within 1 year
Describe treatment strategies for supraorbital and supratrochlear neuralgia
Gabapentin/pregabalin
Topical capsaicin
RF or alcohol rrhizotomy
Peristent cases with exploration and decompression or neurectomy
Name 3 (of 9) interventions that have been used for post herpetic neuralgia
- Nerve blocks
- Cordotomy
- Rhizotomy
- Neurectomy
- Sympathectomy
- DREZ lesioning
- Spinal cord stimulators (Melzack and Wall - gate control theory of pain)
- Undermining skin
- Motor cortex stimulation (for facial PHN)
What’s the triad of Complex Regional Pain Syndrome? (Causalgia/Reflex Sympathetic Dystrophy)
Burning Pain
Autonomic Dysfunction
Trophic Changes
Give 5 proposed treatments for CRPS
- Tricyclic antidepressants
- Sympathetic blocks
- Intravenous regional sympathetic block
- Surgical sympathectomy
- Spinal cord stimulation
