Role of analgesic discography in the diagnosis of discogenic pain syndrome.

Aim: To evaluate the efficacy of a application of analgesic discography in the diagnosis of lumbar DPS and to analyze the correlation of the procedure results with clinical and structural (MRI) predictors. Materials and Methods. A retrospective multicenter study was conducted involving 103 patients with intractable CLBP (duration 3 months, NRS score 4) caused by isolated single-level intervertebral disc lesion (Pfirrmann II-IV). AD was performed with the administration of 1.0–1.5 ml of local anesthetic without creating excessive pressure. A positive result was defined as a more than 50% reduction in NRS pain score. The association of AD outcomes with the presence of Modic endplate changes, High-Intensity Zones (HIZ) on MRI, Pfirrmann degeneration grade, and the clinical pattern of pain was evaluated. Results. A positive AD result was recorded in 31.1% (32/103) of patients; the median pain intensity in this group decreased from 7 to 2 points on the NRS (p 0,001). Atypical prolonged analgesia, interpreted as a false-positive effect, was noted in 4 patients (3.9%). A strong statistically significant association was found between positive discography and Modic 1 changes (OR = 14.60; 95% CI: 3.74–56.80), as well as a moderate association with HIZ (OR = 3.93; 95% CI: 1.60–9.68). Modic 2 changes (fatty degeneration) showed no significant association with discography outcome (OR = 0.87; p = 0.82). The association with the clinical pain pattern, as well as with the degree of structural disc degeneration (Pfirrmann) and the topical level of the lesion, was not statistically significant (p 0.05). Conclusion. Analgesic discography is an effective and safe method for verifying DPS. A strong correlation was found between a positive response to intradiscal anesthetic and MRI predictors (Modic 1, HIZ), which substantiates the chemical sensitization of nociceptors as the leading mechanism of the pain syndrome. Structural disc degeneration (loss of height) is not a reliable predictor of discogenic pain. Keywords: chronic low back pain, discogenic pain, analgesic discography, provocative discography, Modic changes, HIZ, minimally invasive spine surgery.