The frequency of NP was 42.8% during the common lumboradiculalgia. Age over 60 years, spinal stiffness and radiculalgia were statistically associated with NP. In terms of imaging, lumbar osteoarthritis, disc protrusion and posterior interaphyseal osteoarthritis were also significantly associated with neuropathic pain.
Any interpretation of these results must take into account the limitations and biases of our study. As CT and MRI scans were not systematic, other types of disc or degenerative lesions (herniated disc, disc protrusion, posterior interaphyseal osteoarthritis) or inflammatory lesions (spondylodiscitis) may have been overlooked in our study. The absence of a biological inflammatory syndrome in the C Reactive Protein and the sedimentation rate was intended to minimize these cases.
The average age of the patients was 51.75 ± 13.84 years. This is comparable to the data in the literature [11, 13]. Our series was dominated by housewives and shopkeepers. Although low back pain affects 70% of the working-age population, the predominance of housewives and shopkeepers may be due to a selection bias with regard to the proportion of this socio-professional category in African populations . The household activities of housewives and the predominantly informal nature of trade in our context could also explain these results.
The frequency of NP was 42.8%. This frequency is higher than the 28.1% reported by Douala et al. in Cameroon . However, it is comparable to the results previously reported in Burkina Faso and Kaki et al in Saudi Arabia, which were 49.5% and 54.7% respectively [8, 10]. According to two meta-analyses published in 2017, the frequency of LBP varies between 19 and 80% during low back pain and lumboradiculalgia [4, 6]. This significant variation in the frequency of LBP in common low back pain and lumboradiculalgia could be explained by the diversity of study methods, the heterogeneity of the study populations, and especially the multitude of languages in which the DN4 questionnaire is translated and administered.
Age over 60 years seems to predispose to the presence of NP during common lumboradiculalgia (p < 0.01). Adoukonou et al also reported that advanced age was associated with neuropathic pain . In our series, the history of chronic low back pain was not statistically associated with LBP (p = 0.48). Some studies have shown that both acute and chronic low back pain are not associated with LBP [4, 6]. The existence of radiculalgia was statistically associated with the presence of NP (p < 0.01). This could be explained by the fact that radiculalgia is the clinical expression of nerve root pain. Etiologically, facet joint osteoarthritis and protrusive disc disease were statistically associated with NP (p < 0.01). During lumboradiculalgia, functional alterations of the nerve roots may result from compressions corresponding to significant reductions in the spinal canal . Ductal narrowing by disc protrusion, intracanal osteophytes, and hypertrophy of the yellow ligaments frequently associated with facet joint osteoarthritis could explain this association. Our study did not find a significant association between disc herniation and NP (p = 0.08). Symptomatic disc herniation is generally associated with a biochemical inflammatory phenomenon and therefore rather responsible for pain due to excess nociception; also, the natural evolution of a disc herniation is marked by the improvement of clinical symptoms but also a decrease in volume, or even disappearance of the hernia in more than half of the cases . Only 20 to 40% of radiological disc herniations are symptomatic according to the literature [15, 16]. The excess weight found in our study (61.6%) and frequently associated with low back pain and lumboradiculalgia does not seem to be statistically related to the occurrence of LBP.