['The primary aim of this pilot investigation was to identify structural brain differences in older adults with chronic low back pain (CLBP) as compared with pain-free individuals.', 'Cross-sectional, case-control.', 'Sixteen cognitively intact older adults, eight with CLBP and eight pain-free; excluded if with psychiatric or neurological disorders, substance abuse, opioid use, diabetes mellitus, and/or hypertension.', 'Brain magnetic resonance imaging (MRI) and tests of neuropsychological performance (digit span, digit symbol substitution, letter-number sequencing, trail making) were administered to all participants. Gray matter (GM), white matter (WM), cerebrospinal fluid, and corpus callosum (CC) volumes were measured as a percentage of total supratentorial intracranial volume. Voxel-based morphometry analysis of GM and WM assessed regional differences.', 'Between-groups analysis revealed a non-significant trend toward decreased middle CC volume in the CLBP group (1.43E-03 +/- 2.67E-04, 1.63E-03 +/- 2.00E-04: P = 0.09). Regional analysis in the CLBP group demonstrated significantly decreased GM volume (P < 0.001) in the posterior parietal cortex and middle cingulate WM volume (P < 0.001) of the left hemisphere. CLBP participants performed significantly worse on digit span forward (P = 0.03).'] Is chronic pain associated with brain volume loss in older adults : preliminary evidence?