OBJECTIVE: Fibromyalgia (FM) is a chronic widespread pain condition that is thought to arise from augmentation of central neural activity. Glutamate (Glu) is an excitatory neurotransmitter that functions in pain-processing pathways. This study was carried out to investigate the relationship between changing levels of Glu within the insula and changes in multiple pain domains in patients with FM. METHODS: Ten patients with FM underwent 2 sessions of proton magnetic resonance spectroscopy (H-MRS) and 2 sessions of functional magnetic resonance imaging (FMRI), each conducted before and after a nonpharmacologic intervention to reduce pain. During H-MRS, the anterior and posterior insular regions were examined separately using single-voxel spectroscopy. The levels of Glu and other metabolites were estimated relative to levels of creatine (Cr) (e.g., the Glu/Cr ratio). During FMRI, painful pressures were applied to the thumbnail to elicit neuronal activation. Experimental pressure-evoked pain thresholds and clinical pain ratings (on the Short Form of the McGill Pain Questionnaire [SF-MPQ]) were also assessed prior to each imaging session RESULTS: Both experimental pain (P = 0.047 versus pretreatment) and SF-MPQ-rated clinical pain (P = 0.043 versus pretreatment) were reduced following treatment. Changes from pre- to posttreatment in Glu/Cr were negatively correlated with changes in experimental pain thresholds (r = -0.95, P < 0.001) and positively correlated with changes in clinical pain (r = 0.85, P = 0.002). Changes in the FMRI-determined blood oxygenation level-dependent effect (a measure of neural activation) were positively correlated with changes in Glu/Cr within the contralateral insula (r = 0.81, P = 0.002). CONCLUSION: Changes in Glu levels within the insula are associated with changes in multiple pain domains in patients with FM. Thus, H-MRS data may serve as a useful biomarker and surrogate end point for clinical trials of FM.
RCT Entities:
OBJECTIVE:Fibromyalgia (FM) is a chronic widespread pain condition that is thought to arise from augmentation of central neural activity. Glutamate (Glu) is an excitatory neurotransmitter that functions in pain-processing pathways. This study was carried out to investigate the relationship between changing levels of Glu within the insula and changes in multiple pain domains in patients with FM. METHODS: Ten patients with FM underwent 2 sessions of proton magnetic resonance spectroscopy (H-MRS) and 2 sessions of functional magnetic resonance imaging (FMRI), each conducted before and after a nonpharmacologic intervention to reduce pain. During H-MRS, the anterior and posterior insular regions were examined separately using single-voxel spectroscopy. The levels of Glu and other metabolites were estimated relative to levels of creatine (Cr) (e.g., the Glu/Cr ratio). During FMRI, painful pressures were applied to the thumbnail to elicit neuronal activation. Experimental pressure-evoked pain thresholds and clinical pain ratings (on the Short Form of the McGill Pain Questionnaire [SF-MPQ]) were also assessed prior to each imaging session RESULTS: Both experimental pain (P = 0.047 versus pretreatment) and SF-MPQ-rated clinical pain (P = 0.043 versus pretreatment) were reduced following treatment. Changes from pre- to posttreatment in Glu/Cr were negatively correlated with changes in experimental pain thresholds (r = -0.95, P < 0.001) and positively correlated with changes in clinical pain (r = 0.85, P = 0.002). Changes in the FMRI-determined blood oxygenation level-dependent effect (a measure of neural activation) were positively correlated with changes in Glu/Cr within the contralateral insula (r = 0.81, P = 0.002). CONCLUSION: Changes in Glu levels within the insula are associated with changes in multiple pain domains in patients with FM. Thus, H-MRS data may serve as a useful biomarker and surrogate end point for clinical trials of FM.
Authors: Patricia Cagnoli; Richard E Harris; Dan Frechtling; George Berkis; Richard H Gracley; Courtney C Graft; Suzan E Lowe; Thomas L Chenevert; William J McCune; Stephen Gebarski; Pia C Sundgren Journal: Acad Radiol Date: 2013-10 Impact factor: 3.173
Authors: P Feraco; A Bacci; Fab Pedrabissi; L Passamonti; G Zampogna; Fed Pedrabissi; N Malavolta; M Leonardi Journal: AJNR Am J Neuroradiol Date: 2011-07-28 Impact factor: 3.825
Authors: Steven E Harte; Mainak Mitra; Eric A Ichesco; Megan E Halvorson; Daniel J Clauw; Albert J Shih; Grant H Kruger Journal: Med Biol Eng Comput Date: 2013-02-05 Impact factor: 2.602