Isolated radiculopathy caused by symptomatic disc herniation:
analysis of the knee jerk reflex

published in January - February 2019 - in Il Fisioterapista - issue n.1
Massimo Bitocchi

Objective: the aim of this article was to assess the statistical data reported in the literature regarding L5 radiculopathy.
Introduction: Radiculopathy represents a condition involving a spinal nerve root which may result from compression related to intervertebral disc displacement, spinal cord injuries, spinal diseases, and other conditions. Its clinical manifestation includes pain radiating from the nerve root that tends to approximate the dermatomal distribution of the nerve root affected (most often L5, S1) and is often associated with numbness or pins and needles in the same distribution. Further clinical findings of neurologic deficit such as muscle weakness, deep tendon reflex changes and sensory loss may also be present.
Method: To this end, we searched the current literature for relevant studies, without over employing a specific methodological criterion for identifying and analyzing the literature.
Results: EMG anomalies are more frequent in subjects with an absent or reduced knee reflex, i.e. they are observed in 64.7% (11/17 patients) vs. 20.5% (8/39) of subjects with normal knee jerk reflex. At multivariate analysis, the EMG assessment variable reports a positive coefficient equal to 1.2667 corresponding to a higher probability (almost 3.5 times) of observing an abnormal knee reflex.
Conclusion: The findings reported in the study by Ginanneschi et al. suggest that knee jerk reflex impairment cannot be used to disprove a clinical suspicion of L5 monoradiculopathy.