Pressure Increase in the Dorsal Root Ganglion following Mechanical Compression: Closed Compartment Syndrome in Nerve RootsRYDEVIK, BJÖRN L., MD, PhD*; MYERS, ROBERT R., PhD†; POWELL, HENRY C., MD†Spine: June 1989 - Volume 14 - Issue 6 - p 574-576 Original Article: PDF Only Buy Abstract Author InformationAuthors Spinal nerve roots including the dorsal root ganglion (DRG) often are mechanically deformed in connection with degenerative and traumatic conditions of the spine. However, the pathophysiology underlying various functional changes, including pain production, in such conditions is incompletely known. In this study, the tissue fluid pressure in the DRG of L5 nerve roots of rats was measured before and after compression. Normal values were found to be 3.7 ± 0.3 cm H2O (2.7 ± 0.2 mm Hg). After mechanical compression, the endoneurial fluid pressure in the ganglia rose to 9.6 ± 1.7 cm H2O (7.1 ± 1.2 mm Hg) (P < 0.001). Histologic examination revealed edema and haemorrhage in the endoneurial space of the DRG. Pressure increase in the DRG as a result of mechanical deformation by, for example, a herniated disc might be expected to reduce blood flow to the sensory nerve cell bodies in the DRG. This may be a mechanism underlying the production of nerve root pain, which previously has not been described. *From the Division of Orthopaedics and Rehabilitation, Department of Surgery, University of California, San Diego, San Diego, California, and the Department of Orthopaedics, Gothenburg University, Sahlgren Hospital, Gothenburg, Sweden †From the Departments of Anesthesiology, Neurosciences and Neuropathology: VA Medical Center and the University of California, San Diego, San Diego, California © Lippincott-Raven Publishers.