Research PapersAbnormal brain chemistry in chronic back pain: an in vivo proton magnetic resonance spectroscopy studyGrachev, Igor D.a,b,*; Fredrickson, Bruce E.c; Apkarian, Vania A.a,bAuthor Information aDepartment of Neurosurgery, SUNY Upstate Medical University, Syracuse, NY 13210, USA bDepartment of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA cDepartment of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, NY 13210, USA *Corresponding author. Department of Neurosurgery, SUNY Upstate Medical University, 750 E. Adams St, WSK 3118, Syracuse, NY 13210, USA. Tel.: +1-315-464-5582; fax: +1-315-464-5504 E-mail: [email protected] Received 18 January 2000; received in revised form 19 April 2000; accepted 2 May 2000. Pain: December 2000 - Volume 89 - Issue 1 - p 7-18 doi: 10.1016/S0304-3959(00)00340-7 Buy Metrics Abstract The neurobiology of chronic pain, including chronic back pain, is unknown. Structural imaging studies of the spine cannot explain all cases of chronic back pain. Functional brain imaging studies indicate that the brain activation patterns are different between chronic pain patients and normal subjects, and the thalamus, and prefrontal and cingulate cortices are involved in some types of chronic pain. Animal models of chronic pain suggest abnormal spinal cord chemistry. Does chronic pain cause brain chemistry changes? We examined brain chemistry changes in patients with chronic back pain using in vivo single- voxel proton magnetic resonance spectroscopy (1H-MRS). In vivo 1H-MRS was used to measure relative concentrations of N-acetyl aspartate, creatine, choline, glutamate, glutamine, γ-aminobutyric acid, inositol, glucose and lactate in relation to the concentration of creatine. These measurements were performed in six brain regions of nine chronic low back pain patients and 11 normal volunteers. All chronic back pain subjects underwent clinical evaluation and perceptual measures of pain and anxiety. We show that chronic back pain alters the human brain chemistry. Reductions of N-acetyl aspartate and glucose were demonstrated in the dorsolateral prefrontal cortex. Cingulate, sensorimotor, and other brain regions showed no chemical concentration differences. In chronic back pain, the interrelationship between chemicals within and across brain regions was abnormal, and there was a specific relationship between regional chemicals and perceptual measures of pain and anxiety. These findings provide direct evidence of abnormal brain chemistry in chronic back pain, which may be useful in diagnosis and future development of more effective pharmacological treatments. © 2000 Lippincott Williams & Wilkins, Inc.