Diagnostic accuracy of standardised qualitative sensory test in the detection of lumbar lateral stenosis involving the L5 nerve root

Abstract

Misdiagnosis of symptomatic lumbar lateral stenosis (LS) may result in an unfavourable prognosis after surgical treatment. This study investigated the diagnostic accuracy of a standardised qualitative sensory test (SQST) in the detection of symptomatic LS in patients who had degenerative spinal disorders involving the L5 spinal nerve. We prospectively identified 75 patients, of which 60 met the inclusion criteria. Lateral recess stenosis at the L5 level or foraminal stenosis at the L5/S1 level on MRI was identified and graded by a neurosurgeon blinded to any clinical information. The reference criteria for the diagnosis of symptomatic LS were grade III LS on MRI and relevant clinical symptoms. Cutaneous sensory functions of the L5 dermatome on the symptomatic side were evaluated using the SQST. Each item of the SQST showed a satisfactory performance in the diagnosis of LS (sensitivity = 0.455–0.727, specificity = 0.868–1.0). A stepwise selection model identified low-strength von-Frey, high-strength von-Frey, and vibration as the most accurate predictors of symptomatic LS with an area under the receiver operating characteristic curve of 0.9563 (95% confidence interval = 0.9003–1.0). In combination with MRI, the SQST is a promising diagnostic tool for detecting symptomatic LS involving L5 nerve roots.

Diagnostic utility of patient history, clinical examination and screening tool data to identify neuropathic pain in low back related leg pain: a systematic review and narrative synthesis

“…One study did not report the age of participants [33]. The phenomena of interest varied significantly between studies; two studies investigated lumbosacral nerve root compression [19,34], one study investigated participants with upper/mid lumbar nerve root compression [32] and another looked specifically at L5 lateral stenosis [17]. Two studies investigated peripheral NP and chronic low back pain respectively [18,30] with and without leg pain, whereas Capra et al [16] investigated sciatica with or without lumbar pain.…”

“…One study investigated the diagnostic accuracy of patient history data [34], whilst two studies investigated both patient history data and clinical examination data [18,19]. Finally the remaining six studies investigated the use of clinical examination tests; Straight leg raise (SLR) [16], Slump test [33], slump knee bend [32], nerve palpation [35], standardised qualitative sensory testing (SQST) [17], and bell test/hyperextension test [31].…”

“…The most commonly used reference standard test was magnetic resonance imaging (MRI); this was used in six of the included studies [16,17,19,31,32,34], one of which used MRI and/or another imaging technique (computed tomography & saccoradiculography) as a reference standard [31]. Four studies used clinical judgement as a reference standard through a clinical examination [12,18,30,33].…”

“…However, these tools are yet to be validated in identifying NP in LBLP and, the literature regarding superiority of one over the other is varied and conflicting [13,15]. Similarly, research investigating the use of patient history and clinical examination items to diagnose NP in LBLP is lacking and inconclusive [16,17]. Two separate studies have devised a list of clinical indicators using patient history and clinical examination items to identify peripheral NP in patients with or without leg pain [18] and in lumbosacral nerve root compression [19].…”

Sensing acidosis: nociception or sngception?

“…However, in our experience, soreness (or sng) is a predominant sensory phenotype in patients with fibromyalgia and radiculopathy. In our series, soreness is not only one of the major complaints in lumbar stenosis-related low back pain, but also is one of the major reasons for surgical intervention because current treatment for soreness is unsatisfactory [ 42 ]. Therefore, soreness can be another major component in chronic pain disorders but is not yet valued.…”