Current hypothesis says, it’s caused by aberrant peripheral and central pain processing.
Two key features are allodynia, that is, pain in response to a non-painful stimulus and hyperaesthesia, which is, exaggerated perception of pain in response to mildly painful stimulus.
Modern research says, certain antidepressants- with both serotonergic and noradrenergic activity- such as TCAs and venlafaxine, can relieve pain and other symptoms; suggesting the pathway involvement.
Some evidence says, alternative therapies such as acupuncture and spa therapies alleviate pain, which have been postulated to act via similar spinal pain-modulatory pathways.
CSF studies show increased levels of substance P, with decreased levels of noradrenaline and serotonin metabolites. All three are neurotransmitters involved in descending pain-modulatory pathways in the spinal cord.
PET images show an abnormal central dopamine response to pain.
The critical question here is: what is cause and what is effect?
Small sample size and short periods of study, remain the most cumbersome challenge to our complete understanding of fibromyalgia.
Thank you for reading.
- Ashish Singh.