Abnormal Inflammation of Nerve Roots
resulting in significant swelling

With the aging population, an increasing number of individuals are affected by degenerative lumbar diseases. While nonsurgical treatments are preferred initially, some patients eventually require surgery for relief.

Various surgical methods have been developed, but neurological complications and postoperative radiating pain remain important concerns. This article discusses excessive nerve root edema as a specific cause of postoperative radiating pain.

The aim of this study is to explore the link between nerve root edema and the recurrence of radicular pain following surgical procedures.

Although some patients initially experienced temporary relief from leg pain after surgery, the pain resurfaced and worsened over time. Non-steroidal anti-inflammatory drugs and mannitol infusion provided limited effectiveness in alleviating the pain.

There were no significant differences in the preoperative diameters of the involved nerve roots between the study and control groups. However, after surgery, both groups experienced swelling in the nerve root.

The mean diameter of the affected nerve roots increased significantly in both groups. Patients with recurring leg pain had larger nerve root diameters compared to the control group.

The reoperation verified the presence of pronounced enlargement in the affected nerve roots, aligning with the observations from MRI scans. Alternative factors contributing to the condition were eliminated. Out of the 13 patients with nerve root edema, 8 exhibited a constricted passageway due to the swelling.

Subsequent to a four-week period, complete relief was reported by 7 patients, whereas 5 patients underwent foraminotomy despite the absence of apparent constriction. The swollen nerve roots were thoroughly cleansed using a dexamethasone-infused saline solution.

Patients experienced noticeable relief within 48 hours following the operation, indicated by a reduction in the average VAS score. However, the VAS score increased after the recurrence of neuralgia.

The VAS score prior to the second operation did not differ significantly from the score before the initial operation. After a four-week period, both the VAS score and ODI showed significant decreases.

At three months following the reoperation, both the VAS score and ODI were lower than the scores at four weeks. Notably, the SF-36 score assessed at three months exhibited a substantial improvement compared to the score at four weeks.

The control group experienced a significant decrease in VAS scores 48 hours after surgery, with further reductions observed at 4 weeks and during the 3-month follow-up. The improvements in VAS scores indicated significant pain relief.

However, there were no notable changes in the ODI and SF-36 scores, suggesting that surgery primarily affected pain levels rather than overall quality of life in the control group.

The analysis conducted before the surgery indicated no significant disparities in VAS, ODI, and SF-36 scores between the study and control groups. Within 48 hours of the operation, the VAS scores exhibited comparable results for both groups.

After re-exploration, the study group experienced comparable pain relief to the control group at the 4-week mark, although their quality of life scores remained lower. Notably, there were no noteworthy distinctions in clinical outcomes between the two groups at the 3-month post-surgery assessment.

As degenerative lumbar diseases become more common, surgical interventions are frequently required to address lower back pain and lower extremity symptoms. However, certain patients encounter a transient improvement followed by the return of symptoms post-surgery.

Further investigations and re-exploration revealed an unexpected swelling of the affected nerve root in these individuals. This atypical nerve root edema is believed to play a role in the development of leg pain after the operation.

An excess swelling of the nerve roots can lead to the entrapment of the lumbar nerves, particularly in cases where there is limited space in the osseous foramina or lateral recess.

Although the initial surgery brought relief to most patients, individuals with abnormal nerve root edema experienced a recurrence of radicular pain due to severe swelling. The nerve roots continue to swell throughout the temporary relief phase until leg symptoms reappear.

The research reported by literature demonstrated that when nerve roots become swollen, they can be compressed by bony structures, resulting in lumbar radiculopathy due to relative stenosis of the intervertebral foramina.

To prevent recurring radiculopathy, surgeons should take into account the thickness of the nerve roots and ensure adequate space during decompression. The study also observed that allergic reactions and specific factors may impact surgical outcomes and the reappearance of symptoms.

It is believed that immune cells and cytokines contribute to the manifestation of root pain, although more investigation is needed to fully comprehend this process.

Over time, pain sensations and quality of life gradually improved for patients who underwent re-exploration. The causes of severe nerve root swelling may include disruption of the spinal canal’s microenvironment during surgery, damage to surrounding veins, and other factors like ligament and fat involvement.

Anti-inflammatory treatments were effective in relieving symptoms. However, further research is needed to better understand the molecular mechanisms behind nerve root edema.

The study’s limitations include a small sample size and retrospective design, highlighting the need for multicenter prospective studies for more comprehensive findings.

Nerve root swelling is a potential consequence of surgical intervention for degenerative lumbar disease and can contribute to recurring radiating pain. Excessive nerve root edema may be associated with an allergic condition.

However, through appropriate re-exploration, the recurrent symptoms can be gradually alleviated.

I am fellowship trained in joint replacement surgery, metabolic bone disorders, sports medicine and trauma. I specialize in total hip and knee replacements, and I have personally written most of the content on this page.

You can see my full CV at my profile page.