Pathophysiology of knee jerk reflex abnormalities in L5 root injury

Ginanneschi, Federica and Mondelli, Mauro and Piu, Pietro and Rossi, Alessandro (2015) Pathophysiology of knee jerk reflex abnormalities in L5 root injury. Functional Neurology, 30 (3). pp. 187-191. ISSN 1971-3274

portiere.php.pdf - Published Version

Download (642kB) | Preview
Official URL:


Although the knee jerk reflex is mediated by the L3 and L4 nerve roots, evidence exists that altered knee jerk expression may occur with exclusively L5 radiculopathy. The present study set out to identify the factors responsible for knee jerk reflex abnormalities in L5 monoradiculopathy. We analyzed clinical and electrophysiological data in 56 subjects affected by L5 monoradiculopathy. Seventeen patients (30.3%) showed an abnormal knee reflex. L5 patients with an abnormal knee reflex differed significantly, in severity of pretibial muscle damage, from those with a normal knee reflex. On the basis of evidence, in humans, of a specific spinal pathway linking the pretibial and quadriceps muscles, we infer that an impairment of the proprioceptive drive from the pretibial muscles to spinal premotor excitatory interneurons contacting quadriceps motor neurons is the main causative factor responsible for reducing knee jerk expression. This mechanism should be considered to avoid misinterpretation of knee jerk reflex changes in lumbar radiculopathies.

Item Type: Article
Uncontrolled Keywords: Basic neuroscience, neurosurgery, spinal cord and root disorders
Subjects: 600 Tecnologia - Scienze applicate > 610 Medicina e salute (Classificare qui la tecnologia dei servizi medici) > 612 Fisiologia umana > 612.8 Funzioni nervose, funzioni sensorie (Classificare qui la Neurofisiologia, la Psicofisiologia)
Depositing User: Marina Spanti
Date Deposited: 24 Sep 2019 11:44
Last Modified: 24 Sep 2019 11:44

Actions (login required)

View Item View Item