TNF and lumbar disc herniation: Two recent experimental studies have shown that using selective serotonin or serotonin–noradrenaline reuptake inhibitors may be associated with reduction of neuropathic pain related to lumbar disk herniation and inhibition of tumor necrosis factor expression after two or three weeks of treatment suggesting the pronociceptive feature of serotonin in lumbar disk herniation-related pain [27, 28].