Neurocognitive Defects & Brain Structure in Fibromyalgia: Are Pain & Cognitive Problems Related?

The journal Brain [2008 Sep 26] just published a study on a fascinating study from the University of Regensburg's Clinic for Rheumatology in Germany.

The researchers write that fibromyalgia patients often report memory and attention problems in addition to pain, stiffness and sleep disturbance. While "accumulating evidence suggests that fibromyalgia is associated with CNS [central nervous system] dysfunction and with an altered brain morphology," there have been few studies that have specifically focused on fibromyalgia patients' neuropsychological issues. Therefore the authors of this study aimed to determine whether fibromyalgia patients' memory and attention problems have any correllation with changes in the morphology (structure and shape) of the brain. They focused specifically on the frontal, temporal and cingulate cortices.

Twenty [fibromyalgia] patients underwent extensive testing for potential neuropsychological deficits, which demonstrated significantly reduced working memory and impaired non-verbal long-term memory (limited to free recall condition) in comparison with normative data from age- and education-matched control groups.

The researchers used a neuroimaging technique called Voxel-based morphometry (VBM) to determine whether there were correlations between neurocognitive test results and the shape/size of the brain in the regions mentioned above.

They found that non-verbal working memory performance was positively correlated with the amount of grey matter in the left dorsolateral prefontal cortex, and verbal working memory performance "was positively correlated with grey matter values in the supplementary motor cortex."

On the other hand, pain scores were negatively correlated with grey matter values in the medial frontal gyrus. White matter analyses revealed comparable correlations for verbal working memory and pain scores in the medial frontal and prefrontal cortex and in the anterior cingulate cortex. The researchers conclude that the study's results provide clear evidence of memory and attention problems in fibromyalgia as well as the correlation of both pain and neurocognitive problems with brain structure:

Our data suggest that, in addition to chronic pain, [fibromyalgia] patients suffer from neurocognitive deficits that correlate with local brain morphology in the frontal lobe and anterior cingulate gyrus, which may be interpreted to indicate structural correlates of pain-cognition interaction.

Monday, October 06, 2008