Patients With Pain Disorder Show Gray-Matter Loss in Pain-Processing Structures: A Voxel-Based Morphometric Study.
Neurologische Klinik und Poliklinik (M.V., M.M., T.S., T.R.T.), Klinikum rechts der Isar, Technische Universität München, Germany; Abteilung Psychosomatik und Psychotherapie (H.G.), Medizinische Hochschule Hannover, Germany; Klinik und Poliklinik für Psychiatrie und Psychotherapie (C.S.), Klinikum rechts der Isar, Technische Universität München, Germany; Klinik und Poliklinik für Psychosomatische Medizin (H.G., P.H.), Psychotherapie und Med. Psychologie, Klinikum rechts der Isar, Technische Universität München, Germany; Abteilung für Neuroradiologie (C.Z.), Institut für Röntgendiagnostik, Klinikum rechts der Isar, Technische Universität München, Germany.
Objective: To investigate whether the functional changes in pain disorder might be reflected by structural brain changes. Pain disorder assessed with the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria is characterized by persistent and distressing chronic pain at one or more body sites which cannot be fully explained by a physiological process or somatic disorder. Psychological factors are thought to play a major role. Recent neuroimaging studies evidenced altered pain processing in patients suffering from this disorder. Methods: Fourteen right-handed women fulfilling the DSM-IV criteria for pain disorder and 25 healthy age-matched women were investigated with magnetic resonance imaging. In the voxel-based morphometry analysis, we compared both groups for changes of gray-matter density. We included age and Beck Depression Inventory scores as nuisance variables to minimize possible confounding effects of age or depressive comorbidity. Results: In the patient group, we found significant gray-matter decreases in the prefrontal, cingulate, and insular cortex. These regions are known to be critically involved in the modulation of subjective pain experiences. Conclusions: In the context of similar results in patients with other functional pain syndromes, such as fibromyalgia and chronic back pain, we suggest that structural changes in fronto-limbic brain circuits represent not only an objective marker of these pain syndromes but also constitute a critical pathophysiological element. These findings represent a further proof of the important role of central changes in pain disorder.
PMID: 19073757 [PubMed - as supplied by publisher]