Malignant peripheral nerve sheath tumor in a patient with neurofibromatosis 1

Many small nerve fibers and nociceptors that contribute to pain transmission were found in the lumbar facet joint and adjacent tissues. Acute inflammation of the facet joint induced prolonged excitation of the mechanoreceptors and a decrease in the mechanical thresholds of receptors. A recent report revealed that inflammatory reactions spread to nerve roots and increased the expression of TNF-α in the DRG.Mechanical noxious stimulation and chemical factors produced by inflammation of the facet joint and/or degeneration of the intervertebral disc may excite nociceptors in the facet joint and adjacent tissues and generate acute or chronic low back pain. Inflammation and degeneration of the facet joint may also induce radiculopathy.