title: Changes in gray matter volume after microsurgical lumbar discectomy: a longitudinal analysis.
abstract: People around the world suffer chronic lower back pain. Because spine imaging often does not explain the degree of perceived pain reported by patients, the role of the processing of nociceptor signals in the brain as the basis of pain perception is gaining increased attention. Modern neuroimaging techniques (including functional and morphometric methods) have produced results that suggest which brain areas may play a crucial role in the perception of acute and chronic pain. In this study, we examined 12 patients with chronic low back pain and sciatica, both resulting from lumbar disc herniation. Structural magnetic resonance imaging (MRI) of the brain was performed 1 day prior to and about 4 weeks after microsurgical lumbar discectomy. The subsequent MRI revealed an increase in gray matter volume in the basal ganglia but a decrease in volume in the hippocampus, which suggests the complexity of the network that involves movement, pain processing, and aspects of memory. Interestingly, volume changes in the hippocampus were significantly correlated to preoperative pain intensity but not to the duration of chronic pain. Mapping structural changes of the brain that result from lumbar disc herniation has the potential to enhance our understanding of the neuropathology of chronic low back pain and sciatica and therefore may help to optimize the decisions we make about conservative and surgical treatments in the future. The possibility of illuminating more of the details of central pain processing in lumbar disc herniation, as well as the accompanying personal and economic impact of pain relief worldwide, calls for future large-scale clinical studies.
authors.affiliation: Department of Neurosurgery, Otto-von-Guericke-University Magdeburg Magdeburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Luchtmann
authors.affiliation: Institute of Biometry and Medical Informatics, Otto-von-Guericke-University Magdeburg Magdeburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Baecke
authors.affiliation: Department of Neurosurgery, Otto-von-Guericke-University Magdeburg Magdeburg, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Steinecke
authors.affiliation: Institute of Biometry and Medical Informatics, Otto-von-Guericke-University Magdeburg Magdeburg, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Bernarding
authors.affiliation: Department of Neurology, Otto-von-Guericke-University Magdeburg Magdeburg, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Tempelmann
authors.affiliation: Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Ragert
authors.affiliation: Department of Neurosurgery, Otto-von-Guericke-University Magdeburg Magdeburg, Germany.
authors.forename: Raimund
authors.initials: R
authors.lastname: Firsching
keywords: chronic low back pain; gray matter volume; lumbar disc herniation; microsurgical lumbar discectomy; structural brain alterations; voxel-based morphometry