Transitional Vertebra and Spina Bifida Occulta Related with Chronic Low Back Pain in a Young Patient.

Bertolotti's syndrome (BS) must be considered as a differential diagnosis in a young patient presenting with low back pain (LBP). We present a case of a 26-year-old male complaining of mild chronic LBP for six years, radiating to his left thigh for the past six months. He has been taking non-steroidal anti-inflammatory drugs (NSAIDs) with skeletal muscle relaxants for pain relief. The X-ray and computed tomography (CT) imagings showed congenital enlargement of the left transverse process of the fifth lumbar (L5) vertebra forming pseudo-articulation with the sacrum and unilateral pars interarticularis defect at the L4 level on the left side, respectively. He has managed with gabapentin 100 mg three times a day for his neuropathic left leg pain. On follow-up, the patient reported that his pain has improved with gabapentin and it decreased from 8/10 to 4/10 on the visual analogue scale.