DREZ Flashcards
What is the main indication for anterolateral cordotomy?
Cancer related pain Pancoast tumour or pain refractory to medications
What is the main indication for DREZ?
Brachial plexus avulsion, spinal cord injury and cancer related pain limited to a specific few dermatomes
When is nucleus caudalis DREZ performed?
Anaesthesia dolorosa, atypical facial pain, post-herpetic facial pain and some deafferentation pain
Where are the cell bodies for A-delta and C-fibres?
In the dorsal root ganglion
Where are the cell bodies for second order neurons?
In the dorsal horn; the axons cross and form the contralateral spinothalamic tract synapsing in the thalamus
Where in the rexed lamina do C and A-delta fibres synapse?
C fibres: 1 & 2
A-delta fibres: 1, 2 and 5
What is the surgical goal of DREZ?
To disrupt second order neurons (cell bodies in the dorsal horn)
Who first described the DREZ procedure?
Sindou 1972
What are the 4 modes of the dorsal horn as described by Woolf?
1 - normal state
2 - suppressed
3 - sensitized
4 - reorganised
What happens in the reorganised state of the dorsal horn?
The large A fibres that terminate deeper in the dorsal horn terminate more superficially in lamina 2 & 3, where the pain fibres terminate. This results in non-painful stimuli being painful.
What % of patients with brachial plexus injury develop deafferentitation pain?
30%
What factors give good results with DREZ for SCI?
When the pain is at the dermatomes related to the spinal cord injury (not subsegmental)
What are the results for DREZ for phantom limb pain?
Unsatisfactory unless associated with root avulsion
What are the options for cancer pain treatment?
Myelotomy, cordotomy, intrathecal pump insertion and DREZ
When is DREZ performed for post-herpetic neuralgia?
When the pain is confined to localised segmental area
