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Fibromyalgia interacts with age to change the brain.

Ceko M, Bushnell MC, Fitzcharles MA, Schweinhardt P - Neuroimage Clin (2013)

Bottom Line: To examine their functional significance, gray matter differences were compared with experimental pain sensitivity.In both age groups, structural brain alterations were associated with experimental pain sensitivity, which was increased in older patients but normal in younger patients.These results suggest that brain structure and function shift from being adaptive in younger to being maladaptive in older patients, which might have important treatment implications.

View Article: PubMed Central - PubMed

Affiliation: Alan Edwards Centre for Research on Pain, McGill University, 3640 University Street, Montreal, Quebec H3A O7C, Canada ; Integrated Program in Neuroscience, McGilll University, 3801 University Street, Montreal Quebec H3A 2B4, Canada ; National Center for Complementary and Alternative Medicine (NCCAM), National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.

ABSTRACT
Although brain plasticity in the form of gray matter increases and decreases has been observed in chronic pain, factors determining the patterns of directionality are largely unknown. Here we tested the hypothesis that fibromyalgia interacts with age to produce distinct patterns of gray matter differences, specifically increases in younger and decreases in older patients, when compared to age-matched healthy controls. The relative contribution of pain duration was also investigated. Regional gray matter was measured in younger (n = 14, mean age 43, range 29-49) and older (n = 14; mean age 55, range 51-60) female fibromyalgia patients and matched controls using voxel-based morphometry and cortical thickness analysis of T1-weighted magnetic resonance images. To examine their functional significance, gray matter differences were compared with experimental pain sensitivity. Diffusion-tensor imaging was used to assess whether white matter changed in parallel with gray matter, and resting-state fMRI was acquired to examine whether pain-related gray matter changes are associated with altered functional connectivity. Older patients showed exclusively decreased gray matter, accompanied by compromised white matter integrity. In contrast, younger patients showed exclusively gray matter increases, namely in the basal ganglia and insula, which were independent of pain duration. Associated white matter changes in younger patients were compatible with gray matter hypertrophy. In both age groups, structural brain alterations were associated with experimental pain sensitivity, which was increased in older patients but normal in younger patients. Whereas more pronounced gray matter decreases in the posterior cingulate cortex were related to increased experimental pain sensitivity in older patients, insular gray matter increases in younger patients correlated with lower pain sensitivity, possibly indicating the recruitment of endogenous pain modulatory mechanisms. This is supported by the finding that the insula in younger patients showed functional decoupling from an important pain-processing region, the dorsal anterior cingulate cortex. These results suggest that brain structure and function shift from being adaptive in younger to being maladaptive in older patients, which might have important treatment implications.

No MeSH data available.


Related in: MedlinePlus

Pain sensitivity in fibromyalgia patients. A) Older patients (full bars) were more sensitive to pressure stimuli applied on the thumb than matched controls (open bars) *p = 0.012 (unpleasantness), #p = 0.052 (intensity). B) Younger patients (full bars) were not more sensitive to pressure than matched controls (open bars; p = 0.304 (unpleasantness), p = 0.426 (intensity)).
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f0020: Pain sensitivity in fibromyalgia patients. A) Older patients (full bars) were more sensitive to pressure stimuli applied on the thumb than matched controls (open bars) *p = 0.012 (unpleasantness), #p = 0.052 (intensity). B) Younger patients (full bars) were not more sensitive to pressure than matched controls (open bars; p = 0.304 (unpleasantness), p = 0.426 (intensity)).

Mentions: Fibromyalgia patients were hypersensitive to a standardized pressure stimulus applied to the thumbnail, rating the stimulus as significantly more unpleasant [patients mean (SD) − 25.89 (24.78), controls − 11.28 (14.86); t = 2.56, padjusted = 0.02], with a trend for higher intensity ratings [patients 99.93 (47.71), controls 75.73 (42.13), t = 1.97, padjusted = 0.074]. This finding was driven by the older patients who rated the pressure stimulus as significantly more unpleasant compared to their matched controls [older patients − 32.74 (22.94), older controls − 12.46 (12.72), t = 2.72, padjusted = 0.016; Fig. 4A, top], whereas younger patients did not [younger patients − 19.05 (25.43), younger controls − 10.20 (17.26), t = 1.05, padjusted = 0.4; Fig. 4A, bottom]. Ratings of unpleasantness were strongly correlated with ratings of intensity (r = − 0.759, p < 0.001), and thus, results for the perceived intensity of the pressure stimulus were similar to those for the unpleasantness ratings. Older patients on average rated the pressure stimulus as painful with a trend for higher ratings compared to their controls [older patients 111.83 (37.25), older controls 78.61 (45.79), t = 2.04, padjusted = 0.072; Fig. 4B, top], while younger patients on average rated the stimulus below the pain threshold and not different from their controls [younger patients 88.02 (55.10), younger controls 73.26 (40.32), t = 0.81, padjusted = 0.54; Fig. 4B, bottom]. Please note that because the psychophysical differences were more pronounced for unpleasantness ratings we used those for further analyses. However, any relationship reported between unpleasantness ratings and gray matter volumes was largely similar when intensity ratings were used as expected with two measures that are highly correlated. Also, when intensity ratings were controlled for, brain measures no longer correlated with unpleasantness (and vice versa), again indicating the shared variance of the two measures.


Fibromyalgia interacts with age to change the brain.

Ceko M, Bushnell MC, Fitzcharles MA, Schweinhardt P - Neuroimage Clin (2013)

Pain sensitivity in fibromyalgia patients. A) Older patients (full bars) were more sensitive to pressure stimuli applied on the thumb than matched controls (open bars) *p = 0.012 (unpleasantness), #p = 0.052 (intensity). B) Younger patients (full bars) were not more sensitive to pressure than matched controls (open bars; p = 0.304 (unpleasantness), p = 0.426 (intensity)).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3814958&req=5

f0020: Pain sensitivity in fibromyalgia patients. A) Older patients (full bars) were more sensitive to pressure stimuli applied on the thumb than matched controls (open bars) *p = 0.012 (unpleasantness), #p = 0.052 (intensity). B) Younger patients (full bars) were not more sensitive to pressure than matched controls (open bars; p = 0.304 (unpleasantness), p = 0.426 (intensity)).
Mentions: Fibromyalgia patients were hypersensitive to a standardized pressure stimulus applied to the thumbnail, rating the stimulus as significantly more unpleasant [patients mean (SD) − 25.89 (24.78), controls − 11.28 (14.86); t = 2.56, padjusted = 0.02], with a trend for higher intensity ratings [patients 99.93 (47.71), controls 75.73 (42.13), t = 1.97, padjusted = 0.074]. This finding was driven by the older patients who rated the pressure stimulus as significantly more unpleasant compared to their matched controls [older patients − 32.74 (22.94), older controls − 12.46 (12.72), t = 2.72, padjusted = 0.016; Fig. 4A, top], whereas younger patients did not [younger patients − 19.05 (25.43), younger controls − 10.20 (17.26), t = 1.05, padjusted = 0.4; Fig. 4A, bottom]. Ratings of unpleasantness were strongly correlated with ratings of intensity (r = − 0.759, p < 0.001), and thus, results for the perceived intensity of the pressure stimulus were similar to those for the unpleasantness ratings. Older patients on average rated the pressure stimulus as painful with a trend for higher ratings compared to their controls [older patients 111.83 (37.25), older controls 78.61 (45.79), t = 2.04, padjusted = 0.072; Fig. 4B, top], while younger patients on average rated the stimulus below the pain threshold and not different from their controls [younger patients 88.02 (55.10), younger controls 73.26 (40.32), t = 0.81, padjusted = 0.54; Fig. 4B, bottom]. Please note that because the psychophysical differences were more pronounced for unpleasantness ratings we used those for further analyses. However, any relationship reported between unpleasantness ratings and gray matter volumes was largely similar when intensity ratings were used as expected with two measures that are highly correlated. Also, when intensity ratings were controlled for, brain measures no longer correlated with unpleasantness (and vice versa), again indicating the shared variance of the two measures.

Bottom Line: To examine their functional significance, gray matter differences were compared with experimental pain sensitivity.In both age groups, structural brain alterations were associated with experimental pain sensitivity, which was increased in older patients but normal in younger patients.These results suggest that brain structure and function shift from being adaptive in younger to being maladaptive in older patients, which might have important treatment implications.

View Article: PubMed Central - PubMed

Affiliation: Alan Edwards Centre for Research on Pain, McGill University, 3640 University Street, Montreal, Quebec H3A O7C, Canada ; Integrated Program in Neuroscience, McGilll University, 3801 University Street, Montreal Quebec H3A 2B4, Canada ; National Center for Complementary and Alternative Medicine (NCCAM), National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.

ABSTRACT
Although brain plasticity in the form of gray matter increases and decreases has been observed in chronic pain, factors determining the patterns of directionality are largely unknown. Here we tested the hypothesis that fibromyalgia interacts with age to produce distinct patterns of gray matter differences, specifically increases in younger and decreases in older patients, when compared to age-matched healthy controls. The relative contribution of pain duration was also investigated. Regional gray matter was measured in younger (n = 14, mean age 43, range 29-49) and older (n = 14; mean age 55, range 51-60) female fibromyalgia patients and matched controls using voxel-based morphometry and cortical thickness analysis of T1-weighted magnetic resonance images. To examine their functional significance, gray matter differences were compared with experimental pain sensitivity. Diffusion-tensor imaging was used to assess whether white matter changed in parallel with gray matter, and resting-state fMRI was acquired to examine whether pain-related gray matter changes are associated with altered functional connectivity. Older patients showed exclusively decreased gray matter, accompanied by compromised white matter integrity. In contrast, younger patients showed exclusively gray matter increases, namely in the basal ganglia and insula, which were independent of pain duration. Associated white matter changes in younger patients were compatible with gray matter hypertrophy. In both age groups, structural brain alterations were associated with experimental pain sensitivity, which was increased in older patients but normal in younger patients. Whereas more pronounced gray matter decreases in the posterior cingulate cortex were related to increased experimental pain sensitivity in older patients, insular gray matter increases in younger patients correlated with lower pain sensitivity, possibly indicating the recruitment of endogenous pain modulatory mechanisms. This is supported by the finding that the insula in younger patients showed functional decoupling from an important pain-processing region, the dorsal anterior cingulate cortex. These results suggest that brain structure and function shift from being adaptive in younger to being maladaptive in older patients, which might have important treatment implications.

No MeSH data available.


Related in: MedlinePlus