In a double-blind, placebo-controlled, dose-response study, Cohen and associates (2009) evaluated the effectiveness of trans-foraminal epidural etanercept for the treatment of sciatica. A total of 24 patients with subacute lumbo-sacral radiculopathy were randomly assigned to receive 2 trans-foraminal epidural injections of 2, 4, or 6 mg of entanercept 2 weeks apart in successive groups of 8. In each group, 2 patients received epidural saline. A parallel epidural canine safety study was conducted using the same injection doses and paradigm as in the clinical study. The animal and human safety studies revealed no behavioral, neurological, or histological evidence of drug-related toxicity. In the clinical arm, significant improvements in leg and back pain were collectively noted for the etanercept-treated patients, but not for the saline group, 1 month after treatment. One patient in the saline group (17 %), 6 patients in the 2-mg group (100 %), and 4 patients each in the 4-mg and 6-mg groups (67 %) reported at least 50 % reduction in leg pain and a positive global perceived effect 1 month after treatment. Six months after treatment, the beneficial effects persisted in all but 1 patient. The authors concluded that epidural entanercept holds promise as a treatment for lumbo-sacral radiculopathy.
Posterior cord syndrome , in which just the dorsal columns of the spinal cord are affected, is usually seen in cases of chronic myelopathy but can also occur with infarction of the posterior spinal artery .  This rare syndrome causes the loss of proprioception and sense of vibration below the level of injury  while motor function and sensation of pain, temperature, and touch remain intact.  Usually posterior cord injuries result from insults like disease or vitamin deficiency rather than trauma.  Tabes dorsalis , due to injury to the posterior part of the spinal cord caused by syphilis, results in loss of touch and proprioceptive sensation.