2020 Oct 13. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan–.
The definition of acute lumbosacral radiculopathy is a diffuse disease process that affects more than one underlying nerve root, causing pain, loss of sensation, and motor function depending on severity. Muscle strength is often preserved in the case of radiculopathy because muscles often receive innervation from multiple roots. There is built-in redundancy to human anatomy, despite a potentially significant injury to a single nerve root. Thus, muscle strength is often only effected in severe cases of radiculopathy. Lumbosacral radiculopathy is very common. Most cases of lumbosacral radiculopathy are self-limited. The most common symptom in radiculopathy is paresthesia. Sensory loss or paraesthesia into the lower extremity, back pain radiating into the foot, with a positive straight leg raising test are a common presentation of lumbar radiculopathy.
The most common cause of lumbar radiculopathy is a herniated disc. A herniated disc can cause nerve root compression. This process can be acute or can develop chronically over time. Imaging is not always a helpful modality in diagnosis. Almost 27% of patients without back pain have been found to have disc herniation on magnetic resonance imaging (MRI). Complicating the diagnosis of radicular pain is how an abnormality such as disc herniation found on an MRI does not appear to be predictive of future development of back pain. To diagnose a herniated disc as a source of a patient's pain, it is important to review the complete history and physical, making sure the symptoms fit the imaging results. Patients with lumbar radicular pain often respond to conservative management. Patients who do not respond to conservative therapies will likely undergo an MRI for further evaluation. Referral from the primary team to a specialist for alternative therapies such as an epidural glucocorticoid injection should be considered as well at that time, depending on the severity of symptoms.