Abstract
This study aimed to test the hypothesis that structural grey matter brain changes might occur in the chronic intractable pain disorder fibromyalgia when this is associated with marked fatigue in the absence of a DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision) diagnosis of affective disorder. High-resolution 3-T cerebral magnetic resonance imaging scans were acquired in 10 female, right-handed, non-smoking, white Caucasian subjects: five patients with fibromyalgia associated with marked fatigue and five age-matched healthy women. Voxel-wise generalized linear modelling of the processed neuroanatomical data using permutation-based non-parametric testing, forming clusters at t > 2.3 and testing clusters for significance at P < 0.05, corrected for multiple comparisons across space, revealed significantly lower grey matter density in the patients with fibromyalgia and marked fatigue in the left supplementary motor area. This brain region plays an important role in cognitive or executive control and in the translation of painful cognition; these functions are impaired in fibromyalgia associated with marked fatigue.