These findings provide further support for a disruption of dopaminergic neurotransmission in FMS and implicate DA as important neurochemical moderator of differences in pain perception in FMS patients with and without co-morbid depression.
We recently saw that a Parkinson's drug called L-dopa that enhances dopamine may be an effective pain drug and asked whether ME/CFS and FM could be Parkinson's like disorders.
The destruction of the dopamine producing neurons in the basal ganglia causes the difficulty Parkinson's patients have in moving as well as their autonomic nervous system problems, their cognitive problems and their mood problems. Most of the dopamine producing neurons in the brain are found in and around the basal ganglia.
Several studies have implicated the basal ganglia in fibromyalgia and chronic fatigue syndrome. A recent study found that reduced blood flows to the basal ganglia are associated with increased pain in fibromyalgia. ME/CFS studies suggest that reduced activation of the basal ganglia is associated with reduced reward and increased fatigue.
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They used a PET scanner to determine how much the D2/D3 dopamine receptors affected these factors. The receptors, at least in part, affect how much dopamine is available in the central nervous system.
They found that dopamine availability in three parts of the basal ganglia (caudate nucleus, striatum and nucleus accumbens) was associated with increased pain sensitivity. The psychological effects on pain were not effected.
This suggests the dopamine enhancing drugs and herbs may be helpful in FM. Pramipexole, in fact, did well in a 2005 controlled, double-blinded fibromyalgia study. FM patients reported a 35% decrease in pain and about 40% had a 50% or greater reduction in pain. Fatigue dropped by an average of 30%.
For more check out:
- Are Fibromaylgia and Chronic Fatigue Syndrome Related to Parkinson's Disease?
- The Dopamine Theory of Neurological Disorders
- Is Dopamine Imbalance a Major Factor in MS and other Neurological Disorders?
Eur Neuropsychopharmacol. 2015 Dec 10. pii: S0924-977X(15)00390-9. doi: 10.1016/j.euroneuro.2015.12.007. [Epub ahead of print] Relation of dopamine receptor 2 binding to pain perception in female fibromyalgia patients with and without depression - A [11C] raclopride PET-study. Ledermann K1, Jenewein J2, Sprott H3, Hasler G4, Schnyder U2, Warnock G5, Johayem A5, Kollias S6, Buck A5, Martin-Soelch C7.
- Dopamine D2/D3 receptor availability at rest and its association with individual pain perception was investigated using the [11C] raclopride PET-method in 24 female Fibromyalgia (FMS) participants with (FMS+, N=11) and without (FMS-, N=13) comorbid depression and in 17 healthy women. Thermal pain thresholds (TPT) and pain responses were assessed outside the scanner. We compared the discriminative capacity, i.e. the individual׳s capacity to discriminate between lower and higher pain intensities and the response criterion, i.e. the subject׳s tendency to report pain during noxious stimulation due to psychological factors. [11C] raclopride binding potential (BP), defined as the ratio of specifically bound non-displaceable radioligand at equilibrium (BPND) was used as measure of D2/D3 receptor availability. We found significant group effects of BPND in striatal regions (left ventral striatum, left caudate nucleus and left nucleus accumbens) between FMS+ and FMS- compared to healthy subjects.
Correlational analysis showed negative associations between TPT and D2/D3 receptor availability in the left caudate nucleus in FMS-, between TPT and D2/D3 receptor availability in the right caudate nucleus in FMS + and positive associations between TPT and D2/D3 receptor availability in the left putamen and right caudate nucleus in healthy controls.
The response criterion was positively associated with D2/D3 receptor availability in the right nucleus accumbens in FMS - and negatively with D2/D3 receptor availability in the left caudate nucleus in healthy controls. Finally, no significant associations between D2/D3 receptor availability and discriminative capacity in any of the groups or regions were determined.
These findings provide further support for a disruption of dopaminergic neurotransmission in FMS and implicate DA as important neurochemical moderator of differences in pain perception in FMS patients with and without co-morbid depression.