Given the task definition and input, reply with output. Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

It is possible that interruption of nociceptive input from intervertebral discs can be modulated through bilateral L1 and L2 dorsal root ganglia (DRG) blockade. In order to test this hypothesis, we prospectively collected data from patients with low-lumbar pain, accurately diagnosed as discogenic using provocation discography.', 'Twelve patients were recruited with a mean (sd) symptom duration of 13.7 (8.2) years. Bilateral DRG blocks of L1 and L2 were performed using methylprednisolone 80 mg, clonidine 75 microg and 0.5% bupivacaine 4 ml in each patient.', 'Analysis of Brief Pain Inventories showed no significant change in pain scores.
Does bilateral L1 and L2 dorsal root ganglion block for discogenic low-back pain?