Neuroimmune relations in patients with fibromyalgia: a positron emission tomography study

To study relations between neural and immune activity in patients with chronic pain, we correlated regional cerebral blood flow measured with [(15)O]butanol positron emission tomography to immune function in five patients with fibromyalgia. Partly replicating previous data in healthy volunteers, natural killer cell activity correlated negatively with right hemisphere activity in the secondary somatosensory and motor cortices as well as the thalamus. Moreover, natural killer cell activity was negatively and bilaterally related to activity in the posterior cingulate cortex. Thus, immune parameters were related to activity in brain areas involved in pain perception, emotion, and attention. Implicated from a small study population, these strong neuro-immune associations are discussed in view of recent findings concerning mechanisms and adaptive values in immuno-cortical communication and regulation.