Objective
To determine the efficacy of transforaminal epidural steroid injections according to nerve root enhancement in lumbar disc herniations. Method: Twenty seven patients who had extruded or seques tered lumbar disc herniations on enhanced MR imaging were investigated: fifteen patients with corresponding nerve root enhancement (enhanced group), and twelve patients without enhancement (non-enhanced group). All patients received transforaminal epidural steroid injection. Clinical outcomes were measured by visual analogue scale (VAS) for back and radicular pain, Oswestry disability index (ODI) before treatment and one month after injection. Results: The averages of VAS for lower extremity and back pain in both groups one month after injection significantly reduced compared to that of pretreatment, respectively (p＜0.001). The amount of decrease in pain in enhanced group was larger than that of non-enhanced group (p＜0.05). The averages of ODI in both group one month after injection significantly reduced compared to that of pretreatment (p＜0.0001), however, there was no difference between the two groups. Conclusion: The nerve root enhancement on contrast-enhanced MR imaging indicates the presence of severe inflammatory reaction of nerve root, which means well-responsiveness to anti-inflammatory treatment such as transforaminal epidural steroid injection, even if patients' symptom is very severe. (J Korean Acad Rehab Med 2010; 34: 204-208)