Optimizing care in lumbar radiculopathy and neurogenic claudication: from injection to inference, and from clinician to algorithm

Verheijen, E.J.A. (2026)

Doctoral Thesis

This thesis focuses on improving the care of patients with lumbar radiculopathy and neurogenic claudication by investigating the effectiveness of transforaminal epidural steroid injections (TEI) and improving the diagnosis and prognosis of lumbar spinal stenosis (LSS). 

Lumbar radiculopathy is a very common but debilitating spinal disorder with a lifetime prevalence up to 43%. TEI is a widely used treatment option, but its use remains a matter of debate. In this thesis it was demonstrated that TEI provide modest but significant short-term improvements compared with placebo. A large retrospective study showed that approximately 70% of patients experience at least some improvement after TEI, regardless of the pathology on MRI. Reviews of prognostic factors found no robust predictors of TEI success, although shorter symptom duration may be associated with better outcomes. Modic type II changes were not associated with treatment response. 

For lumbar spinal stenosis, a novel MRI grading system showed that central canal stenosis is the most reliable and clinically relevant imaging parameter, correlating with postoperative improvement. The grading of LSS on MRI can be automated as reviews demonstrated that deep learning algorithms can accurately detect and classify LSS, approaching human-level performance.

• Lumbar radiculopathy
• Neurogenic claudication
• Transforaminal epidural steroid injection
• Lumbar spinal stenosis
• Lumbar decompression surgery

• All authors: Verheijen, E.J.A.
• Supervisor: Vleggeert-Lankamp, C.L.A.; Staring, M.
• Committee: Gussekloo, J.; Lelieveldt, B.F.W.; Bartels, R.H.M.A.; Arnts, H.
• Qualification: Doctor (dr.)
• Awarding Institution: Faculty of Medicine, Leiden University Medical Center (LUMC), Leiden University
• Date: 2026-06-30
• ISBN (print): 9789465343839
• DOI: doi:10.60602/1887-4307337