Assessment of neuropathic pain in chronic low back syndromes is important. However, there is currently no gold standard for its diagnosis. The aim of this observational cross-sectional study was to assess the neuropathic component of pain in various chronic low back pain syndromes using a range of diagnostic tests.
Included in this study were 63 patients with chronic axial low back pain (ALBP), 48 patients with chronic radicular syndromes (CRS) comprising 23 with discogenic compression (CDRS) and 25 with lumbar spinal stenosis (LSS), and 74 controls. PainDETECT questionnaire (PDQ), quantitative sensory testing (QST), and skin biopsy with evaluation of intraepidermal nerve fiber density (IENFD) were used to assess the neuropathic pain component.
Positive PDQ (≥19) was obtained more frequently in patients with CDRS and LSS (26.1% and 12.0%, respectively) compared with patients with ALBP (1.6%, P<0.001). The proportion of patients with sensory loss confirmed by QST was lowest in the ALBP subgroup (23.8%) compared with CDRS (47.8%), and LSS (68.0%) subgroups (P<0.001). A reduction in IENFD was disclosed in a proportion of up to 52.0% of affected roots in patients with CRS.
Neuropathic pain is quite frequent in CRS, and QST reveals sensory loss as a frequent abnormality in patients with CRS. Using a cut-off value of 19, PDQ identified a neuropathic component in a relatively low proportion of patients with CRS. CRS may be associated with a reduction in IENFD.
*Department of Neurology, University Hospital and Masaryk University Brno
†CEITEC—Central European Institute of Technology
‡Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czech Republic
T.A. and E.K. contributed equally to the article.
Supported by the Ministry of Health of the Czech Republic—conceptual development of research organization (FNBr, 65269705) and Specific University Research Grant MUNI/A/1072/2017 provided by the Ministry of Education, Youth and Sports of the Czech Republic. The authors declare no conflict of interest.
Reprints: Blanka Adamova, MD, PhD, Department of Neurology, University Hospital and Masaryk University, Jihlavska 20, Brno 625 00, Czech Republic (e-mail: firstname.lastname@example.org).
Received March 21, 2018
Received in revised form August 18, 2018
Accepted September 4, 2018