Accuracy of clinical neurological examination in diagnosing lumbo-sacral radiculopathy: a systematic literature review

Background: Lumbar radiculopathy remains a clinical challenge among primary care clinicians in both assessment and diagnosis. This often leads to misdiagnosis and inappropriate treatment of patients resulting in poor health outcomes, exacerbating this already debilitating condition. This review evaluated 12 primary diagnostic accuracy studies that specifically assessed the performance of various individual and grouped clinical neurological tests in detecting nerve root impingement, as established in the current literature. Methods: Eight electronic data bases were searched for relevant articles from inception until July 2016. All primary diagnostic studies which investigated the accuracy of clinical neurological test (s) in diagnosing lumbar radiculopathy among patients with low back and referred leg symptoms were screened for inclusion. Qualifying studies were retrieved and independently assessed for methodological quality using the 'Quality Assessment of Diagnostic tests Accuracy Studies' criteria. Results: A total of 12 studies which investigated standard components of clinical neurological examination of (sensory, motor, tendon reflex and neuro-dynamics) of the lumbo-sacral spine were included. The mean inter-observer agreement on quality assessment by two independent reviewers was fair (k = 0.3 - 0.7). The diagnostic performance of sensory testing using MR imaging as a reference standard demonstrated a sensitivity (confidence interval 95%) 0.61 (0.47- 0.73) and a specificity of 0.63 (0.38- 0.84). Motor tests sensitivity was poor to moderate, ranging from 0.13 (0.04- 0.31) to 0.61 (0.36- 0.83). Generally, the diagnostic performance of reflex testing was notably good with specificity ranging from (confidence interval 95%) 0.60 (0.51- 0.69) to 0.93 (0.87- 0.97) and sensitivity ranging from 0.14 (0.09- 0.21) to 0.67 (0.21- 0.94). Femoral nerve stretch test had a high sensitivity of (confidence interval 95%) 1.00 (0.40- 1.00) and specificity of 0.83 (0.52- 0.98) while SLR test recorded a mean sensitivity of 0.84 (0.72- 0.92) and specificity of 0.78 (0.67- 0.87). Conclusions: There is a scarcity of studies on the diagnostic accuracy of clinical neurological examination testing. Furthermore there seem to be a disconnect among researchers regarding the diagnostic utility of lower limb neuro-dynamic tests which include the Straight Leg Raise and Femoral Nerve tests for sciatic and femoral nerve respectively. Whether these tests are able to detect the presence of disc herniation and subsequent nerve root compression or hyper-sensitivity of the sacral and femoral plexus due to mechanical irritation still remains debatable.