Evaluation of the Neuropathic Component of Chronic Low Back Pain.

OBJECTIVES: 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. MATERIALS AND METHODS: 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. RESULTS: 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. DISCUSSION: 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.

Is there a Correlation Between Degree of Radiologic Lumbar Spinal Stenosis and its Clinical Manifestation?

STUDY DESIGN: This was an observational cross-sectional study. OBJECTIVE: The purpose of this study was to evaluate whether the degree of stenosis on magnetic resonance imaging (MRI) relates to the severity of clinical symptoms, disability, or neurological deficit in patients with symptomatic central lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: The relationship between radiologic findings and the clinical manifestations of LSS remains unclear. MATERIALS AND METHODS: A total of 84 patients (42 men, median age 70 y) with neurogenic claudication and central degenerative LSS were included in the study. The MRI parameters describing severity (anteroposterior diameter of dural sac, cross-sectional area of the dural sac, stenosis ratio, and Schizas qualitative morphologic classification were evaluated at maximum stenotic level) and the extent of stenosis (the number of central stenotic levels) were correlated to symptoms (pain intensity, walking capacity), functional disability (measured in terms of the Oswestry Disability Index), and neurological signs of LSS (neurological status was evaluated and scored by Neurological Impairment Score in LSS). RESULTS: A statistically significant correlation emerged only between the Neurological Impairment Score in LSS and Schizas morphologic classification (P=0.006). Pain intensity, walking capacity, and functional disability displayed no correlation with the MRI parameters of LSS. CONCLUSIONS: LSS is a clinicoradiologic syndrome with complex relationships between degree of radiologic stenosis disclosed by MRI and clinical manifestations. Neurological impairment in the lower extremities reflects the degree of morphologic LSS on MRI. This study did not identify any association between the degree of stenosis and functional disability, pain intensity, or walking capacity. LEVEL OF EVIDENCE: Level II.

Does lumbar spinal stenosis increase the risk of spondylotic cervical spinal cord compression?

PURPOSE: The aim of this prospective cross-sectional observational comparative study was to determine the prevalence of spondylotic cervical cord compression (SCCC) and symptomatic cervical spondylotic myelopathy (CSM) in patients with symptomatic lumbar spinal stenosis (LSS) in comparison with a general population sample and to seek to identify predictors for the development of CSM. METHODS: A group of 78 patients with LSS (48 men, median age 66 years) was compared with a randomly selected age- and sex-matched group of 78 volunteers (38 men, median age 66 years). We evaluated magnetic resonance imaging findings from the cervical spine and neurological examination. RESULTS: The presence of SCCC was demonstrated in 84.6% of patients with LSS, but also in 57.7% of a sample of volunteers randomly recruited from the general population. Clinically symptomatic CSM was found in 16.7% of LSS patients in comparison with 1.3% of volunteers (p = 0.001). Multivariable logistic regression proposed the Oswestry Disability Index of 43% or more as the only independent predictor of symptomatic CSM in LSS patients (OR 9.41, p = 0.008). CONCLUSIONS: The presence of symptomatic LSS increases the risk of SCCC; the prevalence of SCCC is higher in patients with symptomatic LSS in comparison with the general population, with an evident predominance of more serious types of MRI-detected compression and a clinically symptomatic form (CSM). Symptomatic CSM is more likely in LSS patients with higher disability as assessed by the Oswestry Disability Index.